HACKING !
What is hacking?
Hacking can be defined as the process of gaining unauthorised access to a computer or computerised system and the information it contains. Both corporate and home users can be at risk of hacking.
What are the risks to home users?The risk to home users from hacking is growing. Until recently, the use of conventional dial-up modems meant that users tended to be connected to the Internet for relatively short periods of time. However, broadband and cable connections, through which systems can be permanently connected to the Internet, make it easier for hackers to be aware of your presence online and attempt to gain access to your system. Faster connections can also make it easier to transfer information from your system very quickly. Some viruses are known as ‘Trojan Horses’ or ‘Trojans’. Once installed these will open a ‘back door’ to your computer and notify the sender. The sender can then access your computer and open, delete or copy files from it without your knowledge.
In addition, an increasing number of programmes, such as real-time chat applications, act as servers to exchange information online. Your system needs to 'open up' more of its resources to the Internet to do this, which can make it more vulnerable.
What can home users do?There are several steps you can take to help protect your computer and the information it contains:
Use a "firewall", a piece of hardware or software that blocks unauthorised access to your system. Software versions can be found on the Internet, and many computer magazines feature software in their cover CDs.
Don’t leave any files that contain sensitive information – for example, your bank details - where they could easily be found by someone hacking your system.
Make sure you are running the latest versions of any software that acts as a server.
Remember as long as your system is switched on and connected to the Internet, it could be at risk of being hacked. You don’t have to actively be using your system for it to be vulnerable.
As with other Internet crimes, the best cure is prevention. If you have been the victim of a hacker you may not realise until any sensitive information stored on your system has been put to use.
Corporate, business and public sector usersThe risk to businesses and the public sector is high, as the sensitive nature of information held on their computer systems makes them an attractive target for hackers. This makes the use of security technology paramount. Companies should consider the use of dedicated firewall hardware as well as software. They should look at the ways in which the outside can gain access to their network, and ensure that their systems are not using installed default system passwords etc. Organisations dealing with this area include:
Local police forces, who now work in conjunction with the National High-Tech Crime Unit (NHTCU)
Unified Incident Reporting and Alert Scheme (UNIRAS). This scheme's purpose is to ensure the integrity of government, public service and infrastructure-related systems. However, its alerts and briefings are also available to users outside the UNIRAS community, which also welcomes reports of significant threats and vulnerabilities.
Tuesday, August 26, 2008
INTERNET HACKING .
INTERNET HACKING .
Netspionage Costing Billions.
Two years ago, a fifteen-year-old boy logged onto the Internet under the alias 'Comrade'. To some of us, our idea of hacking might include breaking into an email account or viewing confidential company information. However, no one expected that 'Comrade' would cause a three-week shutdown at NASA, steal government email passwords, intercept over 3000 emails and download close to $2 million worth of software used to operate the international space station. If that was not shocking enough, he had twice gained access to the computers used by the Pentagon to monitor threats of nuclear and biological warfare.
Computer hacking has been around for as long as we can remember - certainly as long as we have had a World Wide Web. Occasionally, the news speaks of silly pranks which imply nothing more than a temporary shutdown of a website, although 'Comrades' hack forced a three-week shutdown for repairs and cost the U.S. government $41,000.Recently, the case of the hackers tampering with the CIA's website, changing the title to 'Central Stupidity Agency' and filling it with obscenities was merely a nuisance for the agency. It posed no real threat because the CIA's files are inaccessible via that Internet site. Undoubtedly, there are some who see humour in this - a civilian, probably not even a professional, outwitting an elite US agency. Then there are more serious crimes, which are no laughing matter.In one case of corporate espionage, two 'heavy manufacturing' firms were bidding on a $900 million contract; one outbid the other by a fraction of a percent.This was no co-incidence as the losing company later discovered that someone had broken into the company's computer network and accessed files that contained bidding strategy information.In another case, authorities are chasing an individual who regularly hires U.S. teens to access confidential documents. One young hacker was paid $1,000 - and promised $10,000 more - for stealing design documents for kitchen appliances from U.S. firms.Beyond selling the trade secrets to a company's competition, some hackers resort to extortion of the company. In Sweden, a 15 and 17 year old tried to extort $2 million from a cellular company to destroy information they had illegally downloaded.Like most cases of extortion, the criminal's identity is especially difficult to trace and is magnified because of the nature of the Net.When the Internet was gaining immense popularity, businesses were scrambling to secure domain names and using the technology to expand their market. Seeing e-commerce as an untapped goldmine, many were eagerly diving headfirst into a slew of problems, including security breaches.Companies like eBay, Buy.com, Yahoo! Amazon and Excite were not prepared when 'Mafiaboy' decided to strike. The 16-year-old Montreal teen crippled their sites last year when he bombarded them with thousands of simultaneous messages, preventing legitimate users from gaining access. His five-day tirade caused an estimated $1.7 billion in damages.These malicious and insidious attacks threaten security and cost companies and organizations billions of dollars. A survey of the Fortune 1000 companies in 1999 estimates a loss of $45 billion from information theft.Of course, many organizations are taking extra security measures, including the usage of firewalls (a security mechanism that allows limited access to sites from the Internet).Still, hackers will gain access. If a fifteen year old can shutdown NASA, what hope is there?Recently, Ernst & Young, a major consulting and accounting firm, set up computer labs across North America which allow information security consultants to perform 'ethical hacks' to assess the strengths and weaknesses of a client's networks and systems.By using existing hacker tools, they're fighting fire with fire.'Ethical hackers' are being paid thousands of dollars to provide clients with clear evidence of how vulnerable their networks are to attacks that could compromise their most sensitive information.This is proving an effective way of gauging the level of security within a system.Hacking has become so prevalent that it is almost synonymous with the computer subculture. This "computer geek" culture is portrayed on television (X-files, the Lone Gunmen) and in movies (Hackers, Anti-Trust) as cynical and often self-righteous.With that, there is a sense of rebellion against big business; the proverbial David struggling against a corporate Goliath. In many of these crimes, people do them to defy corporations or the government; money is not always the motive. However, it is an act that is still unacceptable that victimizes all who use the Internet. Viruses, shutdowns, crashes and email hacking will be the burden of the user, a company's money lost to theft will be the burden of its customers and a government's money spent on security will be the burden of its citizens.Is there anyone not affected by Internet crime? Nope.
AntiVirus software is a good start to protecting yourself and your data
Netspionage Costing Billions.
Two years ago, a fifteen-year-old boy logged onto the Internet under the alias 'Comrade'. To some of us, our idea of hacking might include breaking into an email account or viewing confidential company information. However, no one expected that 'Comrade' would cause a three-week shutdown at NASA, steal government email passwords, intercept over 3000 emails and download close to $2 million worth of software used to operate the international space station. If that was not shocking enough, he had twice gained access to the computers used by the Pentagon to monitor threats of nuclear and biological warfare.
Computer hacking has been around for as long as we can remember - certainly as long as we have had a World Wide Web. Occasionally, the news speaks of silly pranks which imply nothing more than a temporary shutdown of a website, although 'Comrades' hack forced a three-week shutdown for repairs and cost the U.S. government $41,000.Recently, the case of the hackers tampering with the CIA's website, changing the title to 'Central Stupidity Agency' and filling it with obscenities was merely a nuisance for the agency. It posed no real threat because the CIA's files are inaccessible via that Internet site. Undoubtedly, there are some who see humour in this - a civilian, probably not even a professional, outwitting an elite US agency. Then there are more serious crimes, which are no laughing matter.In one case of corporate espionage, two 'heavy manufacturing' firms were bidding on a $900 million contract; one outbid the other by a fraction of a percent.This was no co-incidence as the losing company later discovered that someone had broken into the company's computer network and accessed files that contained bidding strategy information.In another case, authorities are chasing an individual who regularly hires U.S. teens to access confidential documents. One young hacker was paid $1,000 - and promised $10,000 more - for stealing design documents for kitchen appliances from U.S. firms.Beyond selling the trade secrets to a company's competition, some hackers resort to extortion of the company. In Sweden, a 15 and 17 year old tried to extort $2 million from a cellular company to destroy information they had illegally downloaded.Like most cases of extortion, the criminal's identity is especially difficult to trace and is magnified because of the nature of the Net.When the Internet was gaining immense popularity, businesses were scrambling to secure domain names and using the technology to expand their market. Seeing e-commerce as an untapped goldmine, many were eagerly diving headfirst into a slew of problems, including security breaches.Companies like eBay, Buy.com, Yahoo! Amazon and Excite were not prepared when 'Mafiaboy' decided to strike. The 16-year-old Montreal teen crippled their sites last year when he bombarded them with thousands of simultaneous messages, preventing legitimate users from gaining access. His five-day tirade caused an estimated $1.7 billion in damages.These malicious and insidious attacks threaten security and cost companies and organizations billions of dollars. A survey of the Fortune 1000 companies in 1999 estimates a loss of $45 billion from information theft.Of course, many organizations are taking extra security measures, including the usage of firewalls (a security mechanism that allows limited access to sites from the Internet).Still, hackers will gain access. If a fifteen year old can shutdown NASA, what hope is there?Recently, Ernst & Young, a major consulting and accounting firm, set up computer labs across North America which allow information security consultants to perform 'ethical hacks' to assess the strengths and weaknesses of a client's networks and systems.By using existing hacker tools, they're fighting fire with fire.'Ethical hackers' are being paid thousands of dollars to provide clients with clear evidence of how vulnerable their networks are to attacks that could compromise their most sensitive information.This is proving an effective way of gauging the level of security within a system.Hacking has become so prevalent that it is almost synonymous with the computer subculture. This "computer geek" culture is portrayed on television (X-files, the Lone Gunmen) and in movies (Hackers, Anti-Trust) as cynical and often self-righteous.With that, there is a sense of rebellion against big business; the proverbial David struggling against a corporate Goliath. In many of these crimes, people do them to defy corporations or the government; money is not always the motive. However, it is an act that is still unacceptable that victimizes all who use the Internet. Viruses, shutdowns, crashes and email hacking will be the burden of the user, a company's money lost to theft will be the burden of its customers and a government's money spent on security will be the burden of its citizens.Is there anyone not affected by Internet crime? Nope.
AntiVirus software is a good start to protecting yourself and your data
Death from the mailroom – iPhone hacks your company from the inside.
Death from the mailroom – iPhone hacks your company from the inside.
Las Vegas (NV) – The Apple iPhone is great for phone calls and viewing YouTube videos, but it can also be turned into one heck of a wireless hacking tool capable of wrecking havoc on almost any company or government organization from the inside. In a talk at the Defcon security convention, Robert Graham and David Maynor of Errata Security explained how they could defeat firewalls, intrusion detection systems and even armed security guards by Fedexing a modified iPhone to a fictitious employee. The phone calls home every hour and can then be instructed to sniff network traffic, discover nearby wireless devices and even download information.
Robert Graham, co-founder and CTO of Errata Security
Graham and Maynor first came up with the idea of the hacking iPhone when a client wanted them to perform a wireless penetration test at a faraway facility. Graham told TG Daily that such a test would have required costly travel and losing nearly a day sitting in airports and on a plane. The simpler way seemed to send them an iPhone with special scanning tools installed.Installing the software wasn’t the biggest problem as you can pretty much do anything to the phone after you jailbreak it. Graham and Maynor had to figure out how to power the phone for several days as it crisscrossed the United States. They also had to figure out how to control the phone from anywhere in the United States because the phone’s IP address would constantly change as it traversed cell towers and wireless access points on its journey.An APC extended battery pack fixed the power issue by providing approximately five days of power in a deck of cards form factor. Graham and Maynor solved the control issue by having the phone call home every hour with an SSH connection. Once connected, the pair could instruct the phone to launch wireless sniffing tools like Graham’s Ferret which enumerates nearby computers and all the hotspots they’ve connected to recently.The phone and the APC battery fit inside the original iPhone box which worked out great for Maynor as he walked to the local UPS store to ship the unit. “I just told people that someone won an eBay auction for an iPhone,” he joked.In initial runs, the iPhone’s scanning showed some interesting results. Graham told the audience that the phone would just sit in a receiving facility, usually a mailroom, for a long time. Fedex and UPS generally will deliver numerous boxes in a shipment and then a secretary or internal mailman (in larger companies) will then sort everything to its final destination. But if the package is addressed to someone who doesn’t work at the company, then employees will have no real urge to move it. Calls need to be made to verify that the employee doesn’t exist and then someone will finally call the shipping company to pick the package – this all takes time, time that the phone can use to scan the internal network.Once the phone was inside a business, Graham said most of the wireless networks were wide open. This should probably come as no surprise as companies usually trust employees and anyone’s who has made it past the front door must be friendly.While the notion of an iPhone attack may seem a bit too Hollywood-ish to some, Graham and Maynor say the idea is much better than a hacker sitting outside of a company sniffing for wireless traffic. They say police and even average citizens are quite suspicious of people sitting in their cars with glowing computers screens. Furthermore sending a company an iPhone means you can completely anonymous with a jailbroken iPhone and a third-party SIM card.Companies typically spend thousands even millions of dollars on physical and network security, but Maynor said their iphone can foil all of that by “getting past all the firewalls and crap that they’re buying.” He added that many organizations have armed guards that will stop any intruders, yet they let in the Fedex guy at 10 AM every morning.Graham was scheduled to demonstrate the sniffing software and promises to release it as open source in the near future. Unfortunately Graham and Maynor weren’t able to demonstrate the software because they accidentally left the prototype in a Las Vegas cab. “Some cabbie now has the power to take down the CIA,” Graham joked.
Las Vegas (NV) – The Apple iPhone is great for phone calls and viewing YouTube videos, but it can also be turned into one heck of a wireless hacking tool capable of wrecking havoc on almost any company or government organization from the inside. In a talk at the Defcon security convention, Robert Graham and David Maynor of Errata Security explained how they could defeat firewalls, intrusion detection systems and even armed security guards by Fedexing a modified iPhone to a fictitious employee. The phone calls home every hour and can then be instructed to sniff network traffic, discover nearby wireless devices and even download information.
Robert Graham, co-founder and CTO of Errata Security
Graham and Maynor first came up with the idea of the hacking iPhone when a client wanted them to perform a wireless penetration test at a faraway facility. Graham told TG Daily that such a test would have required costly travel and losing nearly a day sitting in airports and on a plane. The simpler way seemed to send them an iPhone with special scanning tools installed.Installing the software wasn’t the biggest problem as you can pretty much do anything to the phone after you jailbreak it. Graham and Maynor had to figure out how to power the phone for several days as it crisscrossed the United States. They also had to figure out how to control the phone from anywhere in the United States because the phone’s IP address would constantly change as it traversed cell towers and wireless access points on its journey.An APC extended battery pack fixed the power issue by providing approximately five days of power in a deck of cards form factor. Graham and Maynor solved the control issue by having the phone call home every hour with an SSH connection. Once connected, the pair could instruct the phone to launch wireless sniffing tools like Graham’s Ferret which enumerates nearby computers and all the hotspots they’ve connected to recently.The phone and the APC battery fit inside the original iPhone box which worked out great for Maynor as he walked to the local UPS store to ship the unit. “I just told people that someone won an eBay auction for an iPhone,” he joked.In initial runs, the iPhone’s scanning showed some interesting results. Graham told the audience that the phone would just sit in a receiving facility, usually a mailroom, for a long time. Fedex and UPS generally will deliver numerous boxes in a shipment and then a secretary or internal mailman (in larger companies) will then sort everything to its final destination. But if the package is addressed to someone who doesn’t work at the company, then employees will have no real urge to move it. Calls need to be made to verify that the employee doesn’t exist and then someone will finally call the shipping company to pick the package – this all takes time, time that the phone can use to scan the internal network.Once the phone was inside a business, Graham said most of the wireless networks were wide open. This should probably come as no surprise as companies usually trust employees and anyone’s who has made it past the front door must be friendly.While the notion of an iPhone attack may seem a bit too Hollywood-ish to some, Graham and Maynor say the idea is much better than a hacker sitting outside of a company sniffing for wireless traffic. They say police and even average citizens are quite suspicious of people sitting in their cars with glowing computers screens. Furthermore sending a company an iPhone means you can completely anonymous with a jailbroken iPhone and a third-party SIM card.Companies typically spend thousands even millions of dollars on physical and network security, but Maynor said their iphone can foil all of that by “getting past all the firewalls and crap that they’re buying.” He added that many organizations have armed guards that will stop any intruders, yet they let in the Fedex guy at 10 AM every morning.Graham was scheduled to demonstrate the sniffing software and promises to release it as open source in the near future. Unfortunately Graham and Maynor weren’t able to demonstrate the software because they accidentally left the prototype in a Las Vegas cab. “Some cabbie now has the power to take down the CIA,” Graham joked.
Nine Hacks That Will Make You the Master of Your IPhone.
Nine Hacks That Will Make You the Master of Your IPhone.
Only a few days after the iPhone went on sale, hackers were already kicking the wheels and checking under the hood to see if they could pimp out Apple's locked-down smartphone. After a month, they've made surprising progress. Below, we detail some of the milestone hacks for what has been called "the most significant consumer electronics product ever."
Department of Continuous Improvement
Corrections? Additions? Edit this article in the Wired How To Wiki.
Most of the hacks that have been publicized so far are aimed at controlling or enhancing your own iPhone, but a darker side has emerged too. A security firm announced a possible Wi-Fi-based browser exploit, which could give hackers access to an iPhone's microphone, surfing history and contact information -- and possibly website and e-mail passwords stored on the phone, too. Make no mistake: The iPhone is a magnet for hackers, both good and bad.
The hacks below run the gamut from easy hacks almost anyone can do to advanced mods that require serious hardware and software skills. Proceed at your own risk: With any hack, there is a chance you could permanently damage your iPhone or render it unusable, and you're almost certainly voiding your warranty if you try most of these hacks. You have been warned.
Activate the IPhone Without AT&T Ordinarily, the iPhone needs to be activated from within iTunes and registered with the carrier, AT&T, before it can be used for anything except telling the time and calling 911. Jon Lech Johansen (aka "DVD Jon"), who is notorious for cracking the CSS protection scheme on DVDs, took only five days to write a program that can bypass the activation step. It's called Phone Activation Server 1.0. Of course, if you don't have an AT&T account, the phone part won't work, but this hack does get you Wi-Fi, web surfing, e-mail and music capabilities. Difficulty: Medium Details: DVD Jon Hacks iPhone: No Activation Required
Use the IPhone with a Business or Prepaid Account Once the iPhone has been activated, it is possible to substitute the supplied AT&T SIM with another AT&T or Cingular SIM. Why would you do this? If you already have an account with AT&T, you can transfer it to your iPhone by dropping in your old phone's SIM card. This hack will let you use a business account (otherwise not available for the iPhone) or a pre-paid account with your iPhone. Another way to get a prepaid account for your iPhone is to fake bad credit. Here's how: During activation, keep entering a bogus Social Security number and eventually iTunes will give up and offer you a pre-pay account. Sweet. (The same trick also works if you actually do have bad credit and use your real Social Security number.) Difficulty: Beginner Details: Hackers Saw Through IPhone AT&T Shackles
Play Tilt Tilt is a game which takes advantage of the iPhone's tilt sensors, the things which cause the display to flip when you change the orientation of the handset. Developer Joe Hewitt created Tilt at iPhoneDev Camp, and the game involves tilting the phone to control the main character, Flip, and help him eat falling leaves and butterflies. It's no Wii Tennis, but it is a nice demonstration of the iPhone's innovative controls. Difficulty: Beginner Details: Play Tilt on your iPhone
Store Files on Your IPhone IPhoneDrive is a graphical file transfer tool for the iPhone. Just hook the phone up to your Mac and you can drag and drop files to and from the iPhone, using it as an external hard drive the way God intended. Why on earth Apple didn't include this feature from the start is a mystery, since every other iPod already has a similar capability. IPhoneDrive costs $10. Difficulty: Beginner Details: iPhoneDrive Product Page
Only a few days after the iPhone went on sale, hackers were already kicking the wheels and checking under the hood to see if they could pimp out Apple's locked-down smartphone. After a month, they've made surprising progress. Below, we detail some of the milestone hacks for what has been called "the most significant consumer electronics product ever."
Department of Continuous Improvement
Corrections? Additions? Edit this article in the Wired How To Wiki.
Most of the hacks that have been publicized so far are aimed at controlling or enhancing your own iPhone, but a darker side has emerged too. A security firm announced a possible Wi-Fi-based browser exploit, which could give hackers access to an iPhone's microphone, surfing history and contact information -- and possibly website and e-mail passwords stored on the phone, too. Make no mistake: The iPhone is a magnet for hackers, both good and bad.
The hacks below run the gamut from easy hacks almost anyone can do to advanced mods that require serious hardware and software skills. Proceed at your own risk: With any hack, there is a chance you could permanently damage your iPhone or render it unusable, and you're almost certainly voiding your warranty if you try most of these hacks. You have been warned.
Activate the IPhone Without AT&T Ordinarily, the iPhone needs to be activated from within iTunes and registered with the carrier, AT&T, before it can be used for anything except telling the time and calling 911. Jon Lech Johansen (aka "DVD Jon"), who is notorious for cracking the CSS protection scheme on DVDs, took only five days to write a program that can bypass the activation step. It's called Phone Activation Server 1.0. Of course, if you don't have an AT&T account, the phone part won't work, but this hack does get you Wi-Fi, web surfing, e-mail and music capabilities. Difficulty: Medium Details: DVD Jon Hacks iPhone: No Activation Required
Use the IPhone with a Business or Prepaid Account Once the iPhone has been activated, it is possible to substitute the supplied AT&T SIM with another AT&T or Cingular SIM. Why would you do this? If you already have an account with AT&T, you can transfer it to your iPhone by dropping in your old phone's SIM card. This hack will let you use a business account (otherwise not available for the iPhone) or a pre-paid account with your iPhone. Another way to get a prepaid account for your iPhone is to fake bad credit. Here's how: During activation, keep entering a bogus Social Security number and eventually iTunes will give up and offer you a pre-pay account. Sweet. (The same trick also works if you actually do have bad credit and use your real Social Security number.) Difficulty: Beginner Details: Hackers Saw Through IPhone AT&T Shackles
Play Tilt Tilt is a game which takes advantage of the iPhone's tilt sensors, the things which cause the display to flip when you change the orientation of the handset. Developer Joe Hewitt created Tilt at iPhoneDev Camp, and the game involves tilting the phone to control the main character, Flip, and help him eat falling leaves and butterflies. It's no Wii Tennis, but it is a nice demonstration of the iPhone's innovative controls. Difficulty: Beginner Details: Play Tilt on your iPhone
Store Files on Your IPhone IPhoneDrive is a graphical file transfer tool for the iPhone. Just hook the phone up to your Mac and you can drag and drop files to and from the iPhone, using it as an external hard drive the way God intended. Why on earth Apple didn't include this feature from the start is a mystery, since every other iPod already has a similar capability. IPhoneDrive costs $10. Difficulty: Beginner Details: iPhoneDrive Product Page
Tuesday, May 13, 2008
EARTHQUAKE
EARTHQUAKE
This article is about the natural seismic phenomenon. For other uses, see Earthquake (disambiguation).
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph. The moment magnitude of an earthquake is conventionally reported, or the related and mostly obsolete Richter magnitude, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.
At the Earth's surface, earthquakes manifest themselves by a shaking and sometimes displacement of the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.
In its most generic sense, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments.
An earthquake's point of initial rupture is called its focus or hypocenter. The term epicenter means the point at ground level directly above this.
Global earthquake epicenters, 1963–1998
Global plate tectonic movement
Contents[hide]
1 Naturally occurring earthquakes
2 Size and frequency of occurrence
3 Effects/impacts of earthquakes
3.1 Shaking and ground rupture
3.2 Landslides and avalanches
3.3 Fires
3.4 Soil liquefaction
3.5 Tsunami
3.6 Human impacts
4 Preparation for earthquakes
5 Specific fault articles
6 Major earthquakes
6.1 Pre-20th century
6.2 20th century
6.3 21st century
7 Earthquakes in mythology and religion
8 See also
9 References
10 External links
10.1 Educational
10.2 Seismological data centers
10.2.1 Europe
10.2.2 Japan
10.2.3 United States
10.3 Seismic scales
10.4 Scientific information
10.5 Miscellaneous
Naturally occurring earthquakes
Fault types
Most naturally occurring earthquakes are related to the tectonic nature of the Earth. Such earthquakes are called tectonic earthquakes. The Earth's lithosphere is a patchwork of plates in slow but constant motion caused by the release to space of the heat in the Earth's mantle and core. The heat causes the rock in the Earth to flow on geological timescales, so that the plates move slowly but surely. Plate boundaries lock as the plates move past each other, creating frictional stress. When the frictional stress exceeds a critical value, called local strength, a sudden failure occurs. The boundary of tectonic plates along which failure occurs is called the fault plane. When the failure at the fault plane results in a violent displacement of the Earth's crust, energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface, and cracking of the rock, thus causing an earthquake. This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the Elastic-rebound theory. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth or is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior.[1]
The majority of tectonic earthquakes originate at depths not exceeding tens of kilometers. In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, Deep focus earthquakes may occur at much greater depths (up to seven hundred kilometers). These seismically active areas of subduction are known as Wadati-Benioff zones. These are earthquakes that occur at a depth at which the subducted lithosphere should no longer be brittle, due to the high temperature and pressure. A possible mechanism for the generation of deep focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure.[2]
Earthquakes also often occur in volcanic regions and are caused there, both by tectonic faults and by the movement of magma in volcanoes. Such earthquakes can serve as an early warning of volcanic eruptions.
Sometimes a series of earthquakes occur in a sort of earthquake storm, where the earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, and with some of the later earthquakes as damaging as the early ones. Such a pattern was observed in the sequence of about a dozen earthquakes that struck the North Anatolian Fault in Turkey in the 20th century, the half dozen large earthquakes in New Madrid in 1811-1812, and has been inferred for older anomalous clusters of large earthquakes in the Middle East and in the Mojave Desert.
[edit] Size and frequency of occurrence
This article may not provide balanced geographical coverage on a region.An editor has expressed concern that this article is biased. Please improve this article or discuss the issue on the talk page.
Minor earthquakes occur nearly constantly around the world in places like California and Alaska in the U.S., as well as in Chile, Peru, Indonesia, Iran, India the Azores in Portugal, New Zealand, Greece, Italy, and Japan,[3] Larger earthquakes occur less frequently, the relationship being exponential; for example, roughly ten times as many earthquakes larger than magnitude 4 occur in a particular time period than earthquakes larger than magnitude 5. In the (low seismicity) United Kingdom, for example, it has been calculated that the average recurrences are:
an earthquake of 3.7 - 4.6 every year
an earthquake of 4.7 - 5.5 every 10 years
an earthquake of 5.6 or larger every 100 years.
The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past because of the vast improvement in instrumentation (not because the number of earthquakes has increased). The USGS estimates that, since 1900, there have been an average of 18 major earthquakes (magnitude 7.0-7.9) and one great earthquake (magnitude 8.0 or greater) per year, and that this average has been relatively stable.[4] In fact, in recent years, the number of major earthquakes per year has actually decreased, although this is likely a statistical fluctuation. More detailed statistics on the size and frequency of earthquakes is available from the USGS.[5]
Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-km-long, horseshoe-shaped zone called the circum-Pacific seismic belt, also known as the Pacific Ring of Fire, which for the most part bounds the Pacific Plate.[6][7] Massive earthquakes tend to occur along other plate boundaries, too, such as along the Himalayan Mountains.
With the rapid growth of mega-cities such as Mexico City, Tokyo or Tehran, in areas of high seismic risk, some seismologists are warning that a single quake may claim the lives of up to 3 million people.[8][9][10]
Effects/impacts of earthquakes
1755 copper engraving depicting Lisbon in ruins and in flames after the 1755 Lisbon earthquake. A tsunami overwhelms the ships in the harbor.
Smoldering after the 1906 San Francisco earthquake.
Earthquake damage in Anchorage, Alaska (1964).
Earthquake damage in Mexico City (1985).
Earthquake damage in Armenia (1988).
A section of the Cypress viaduct collapsed during the Loma Prieta Earthquake (1989).
Kaiser Permanente Building destroyed in the Northridge Earthquake (1994).
Damage in Great Hanshin earthquake (1995) in Kobe, Japan.
Chūetsu earthquake (2004).
Please help improve this section by expanding it.Further information might be found on the talk page or at requests for expansion.
There are many effects of earthquakes including, but not limited to the following:
[edit] Shaking and ground rupture
Shaking and ground rupture are the main effects created by earthquakes, principally resulting in more or less severe damage to buildings or other rigid structures. The severity of the local effects depends on the complex combination of the earthquake magnitude, the distance from epicenter, and the local geological and geomorphological conditions, which may amplify or reduce wave propagation. The ground-shaking is measured by ground acceleration.
Specific local geological, geomorphological, and geostructural features can induce high levels of shaking on the ground surface even from low-intensity earthquakes. This effect is called site or local amplification. It is principally due to the transfer of the seismic motion from hard deep soils to soft superficial soils and to effects of seismic energy focalization owing to typical geometrical setting of the deposits.
Ground rupture is a visible breaking and displacement of the earth's surface along the trace of the fault, which may be of the order of few metres in the case of major earthquakes. Ground rupture is a major risk for large engineering structures such as dams, bridges and nuclear power stations and requires careful mapping of existing faults to identify any likely to break the ground surface within the life of the structure.
[edit] Landslides and avalanches
Earthquakes can cause landslides and avalanches, which may cause damage in hilly and mountainous areas.
[edit] Fires
Following an earthquake, fires can be generated by break of the electrical power or gas lines. In the event of water mains rupturing and a loss of pressure, it may also become difficult to stop the spread of a fire once it has started.
[edit] Soil liquefaction
Soil liquefaction occurs when, because of the shaking, water-saturated granular material temporarily loses its strength and transforms from a solid to a liquid. Soil liquefaction may cause rigid structures, as buildings or bridges, to tilt or sink into the liquefied deposits.
[edit] Tsunami
Undersea earthquakes and earthquake-triggered landslides into the sea, can cause Tsunami. See, for example, the 2004 Indian Ocean earthquake.
[edit] Human impacts
Earthquakes may result in disease, lack of basic necessities, loss of life, higher insurance premiums, general property damage, road and bridge damage, and collapse of buildings or destabilization of the base of buildings which may lead to collapse in future earthquakes.
[edit] Preparation for earthquakes
Earthquake preparedness
Household seismic safety
HurriQuake nail (for resisting hurricanes and earthquakes)
Seismic retrofit
Seismic hazard
Mitigation of seismic motion
Earthquake prediction
Pre-20th century
Pompeii (62).
Aleppo Earthquake (1138).
Basel earthquake (1356). Major earthquake that struck Central Europe in 1356.
Carniola earthquake (1511). A major earthquake that shook a large portion of South-Central Europe. Its epicenter was around the town of Idrija, in today's Slovenia. It caused great damage to structures all over Carniola, including Ljubljana, and in western Carinthia, particularly in Villach and Klagenfurt which were almost completely destroyed. There was some minor damage in Venice and other cities, too.
Shaanxi Earthquake (1556). Deadliest known earthquake in history, estimated to have killed 830,000 in China.
Dover Straits earthquake of 1580 (1580).
Dubrovnik earthquake (1667). Disastrous earthquake in Dubrovnik, Croatia killed about 3/5 of the population.
Port Royal Earthquake (1692). An earthquake on June 7, 1692, largely destroyed Port Royal, a safe harbor for pirates, causing two thirds of the city to sink into the Caribbean Sea.
The great Sicilian earthquake (1693). As many as 100,000 may have died.
Cascadia Earthquake (1700).
Tokyo earthquake (1703). 37,000 died.
Kamchatka earthquakes (1737) The third biggest earthquake on record measuring 9.3 on the richter scale.
Lisbon earthquake (1755), one of the most destructive and deadly earthquakes in history, killing between 60,000 and 100,000 people and causing a major tsunami that affected parts of Europe, North Africa and the Caribbean.
Calabria earthquake (1783). Series of 6 earthquakes in Calabria, Italy killed 50,000.[11]
Quito earthquake. (1797) Quito, Viceroyalty of Peru, now the capital of Ecuador, was devastated by an earthquake. 40,000 died.
New Madrid Earthquake (1811), and another tremor (1812) that also struck the small Missouri town, was reportedly the strongest ever in North America and made the Mississippi River temporarily change its direction and permanently altered its course in the region.
Fort Tejon Earthquake (1857). Estimated Richter Scale above 8, said the strongest earthquake in Southern California history.
Great Neapolitan Earthquake (1857). Estimated Richter Scale of 6.9. 11,000 dead.
1872 Lone Pine earthquake (1872). Might been strongest ever measured in California with an estimated Richter Scale of 8.1 said seismologists.
Charleston earthquake (1886). Largest earthquake in the southeastern United States, killed 100.
Ljubljana earthquake (14. IV. 1895), a series of powerful quakes that ultimately had a vital impact on the city of Ljubljana, being a catalyst of its urban renewal.
Assam earthquake of 1897 (1897). Large earthquake that destroyed all masonry structures, measuring more than 8 on the Richter scale.
20th century
San Francisco Earthquake (1906). Between 7.7 and 8.3 magnitudes; killed approximately 3,000 people and caused around $400 million in damage; most devastating earthquake in California and U.S. history.
Messina Earthquake (1908). Killed about 60,000 people.
Gansu earthquake (1920). Killed 200,000 in Gansu province, China.[12]
Great Kantō earthquake (1923). On the Japanese island of Honshū, killing over 140,000 in Tokyo and environs.
1931 Hawke's Bay earthquake. Occurred in the Hawkes Bay in the North Island of New Zealand leaving 256 dead.
1933 Long Beach earthquake
1935 Balochistan earthquake at Quetta, Pakistan measuring 7.7 on the Richter scale. Anywhere from 30,000 to 60,000 people died
1939 Erzincan earthquake at Erzincan, Turkey measuring 7.9 on the Richter scale.
Ashgabat earthquake (1948). Earthquake in Ashgabat, Soviet Union measuring 7.3 on the Richter scale killed over 110,000 (2/3 the population of the city).[13]
Assam earthquake of 1950 (1950). Earthquake in Assam, India measures 8.6M.
Kamchatka earthquakes (1952 and 1737), measuring >9.0.
Great Kern County earthquake (1952). This was second strongest tremor in Southern California history, epicentered 60 miles North of Los Angeles. Major damage in Bakersfield, California and Kern County, California, while it shook the Los Angeles area.
1959 Yellowstone earthquake, formed Quake Lake in southern Montana, USA
Great Chilean Earthquake (1960). Strongest earthquake ever recorded,[14] 9.5 on Moment magnitude scale, and generated tsunamis throughout the Pacific ocean. It measured 9.6 on the Richter scale. [15]
1960 Agadir earthquake, Morocco with around 15,000 casualties.
1963 Skopje earthquake, measuring 6.1 on the Richter scale kills 1,800 people, leaves another 120,000 homeless, and destroys 80% of the city.
Good Friday Earthquake (1964) In Alaska, it was the fourth biggest earthquake recorded,[16] measuring 9.2M. and generated tsunamis throughout the Pacific ocean.
Ancash earthquake (1970). Caused a landslide that buried the town of Yungay, Peru; killed over 40,000 people.
Sylmar earthquake (1971). Caused great and unexpected destruction of freeway bridges and flyways in the San Fernando Valley, leading to the first major seismic retrofits of these types of structures, but not at a sufficient pace to avoid the next California freeway collapse in 1989.
Managua earthquake (1972), which killed more than 10,000 people and destroyed 90% of the city. The earthquake took place on December 23, 1972 at midnight.
Friuli earthquake (1976), Which killed more than 2.000 people in Northeastern Italy and in the Slovenian Littoral on the 6th of May
Tangshan earthquake (1976). The most destructive earthquake of modern times. The official death toll was 255,000, but many experts believe that two or three times that number died.
Guatemala 1976 earthquake (1976). Causing 23,000 deaths, 77,000 injuries and the destruction of more than 250,000 homes.
Coalinga, California earthquake (1983). 6.5 on the Richter scale on a section of the San Andreas Fault. Six people killed, downtown Coalinga, California devastated and oil field blazes.
Great Mexican Earthquake (1985). Killed over 6,500 people, according to official Mexican government reports,[citation needed] but as many as 30,000 people are thought to have been killed (they disappeared and never reappeared after the initial Earthquakes).
Great San Salvador Earthquake (October 10, 1986). Killed over 1,500 people.
Whittier Narrows earthquake (1987).
1989 Newcastle earthquake, Australia
Armenian earthquake (1988). Killed over 25,000.
Loma Prieta earthquake (1989). Severely affecting Santa Cruz, San Francisco, San Jose and Oakland in California. This is also called the World Series Earthquake. It struck as Game 3 of the 1989 World Series was just getting underway at Candlestick Park in San Francisco. Revealed necessity of accelerated seismic retrofit of road and bridge structures.
Iran Earthquake (1990). 7.7 on the Richter scale. Killed over 35,000 in Gilan Province, southwest of Caspian sea.[17]
Luzon Earthquake (1990). On 16 July 1990, an earthquake measuring 7.7 on the Richter scale struck the island of Luzon, Philippines.
Landers, California earthquake (1992). Serious damage in the small town of Yucca Valley, California and was felt across 10 states in Western U.S. Another tremor measured 6.4 struck 3 hours later and felt across Southern California.
August 1993 Guam Earthquake, measuring 8.2 on the Richter scale and lasting 60 seconds.
Northridge, California earthquake (1994). Damage showed seismic resistance deficiencies in modern low-rise apartment construction.
Sakhalin earthquake (1995). Measuring 7.6 on the Richter scale, killing over 2,000 people in Sakhalin, Russia.[18]
Great Hanshin earthquake (1995). Killed over 6,400 people in and around Kobe, Japan.
1998 Afghanistan earthquake (1998). 6.9 on the Richter scale. Some 125 villages were damaged and 4000 people killed.[19]
Athens earthquake (1999). 5.9 on the Richter scale, it hit Athens on September 7. Epicentered 10 miles north of the Greek capital, it claimed 143 lives.
Chi-Chi earthquake (1999) Also called the 921 earthquake. Struck Taiwan on September 21, 1999. Over 2,000 people killed, destroyed or damaged over ten thousand buildings. Caused world computer prices to rise sharply.
Armenia, Colombia (1999) 6.2 on the Richter scale, Killed over 2,000 in the Colombian Coffee Grown Zone.
1999 İzmit earthquake measuring 7.5 on the Richter scale and killed over 17,000 in northwestern Turkey.
Hector Mine earthquake (1999). 7.1 on the Richter scale, epicentered 30 miles east of Barstow, California, widely felt in California and Nevada.
1999 Düzce earthquake at Düzce, Turkey measuring 7.2 on the Richter scale.
Baku earthquake (2000).
[edit] 21st century
Nisqually Earthquake (2001).
El Salvador earthquakes (2001). 7.9 (13 January) and 6.6 (13 February) magnitudes, killed more than 1,100 people.
Gujarat Earthquake (26 January 2001).
Hindu Kush earthquakes (2002). Over 1,100 killed.
Molise earthquake (2002) 26 killed.
Bam Earthquake (2003). Over 40,000 people are reported dead.
Parkfield, California earthquake (2004). Not large (6.0), but the most anticipated and intensely instrumented earthquake ever recorded and likely to offer insights into predicting future earthquakes elsewhere on similar slip-strike fault structures.
Chūetsu earthquake (2004).
Sumatra-Andaman Earthquake (26 December 2004). By some estimates, the second largest earthquake in recorded history (estimates of magnitude vary between 9.1[20] and 9.3). Epicentered off the coast of the Indonesian island of Sumatra, this massive earthquake triggered a series of gigantic tsunamis that smashed onto the shores of a number of nations, causing 230,000 fatalities.
Sumatran (Nias) Earthquake (2005).
Fukuoka earthquake (2005).
Northern Chile Earthquake (2005). 7.9 (13 June). Killed only 15 people, but left many poor families homeless.
Kashmir earthquake (2005) (also known as the Great Pakistan earthquake). Killed over 79,000 people; and many more injured.
Lake Tanganyika earthquake (2005).
May 2006 Java earthquake (2006).
July 2006 7.7 magnitude Java earthquake which triggered tsunamis (2006).
October 2006 6.6 magnitude Kona, Hawaii earthquake (2006).
November 2006 8.1 magnitude north of Japan (2006).
December 26, 2006, 7.2 magnitude, southwest of Taiwan (2006).
Sumatra Earthquakes March 06, 2007, 6.4 and 6.3 magnitude, Sumatra, Indonesia (2007).
March 25, 2007, 6.9 magnitude, off the west coast of Honshū, Japan (2007).
April 1, 2007, 8.1 magnitude, Solomon Islands (2007).
2007 Guatemala Earthquake 6.7 magnitude (2007).
July 16, 2007, 6.6 magnitude, Niigata prefecture, Japan (2007).
2007 Peru earthquake 8.0 magnitude, August 15 (2007)[21]
September 2007 Sumatra earthquakes 8.0 magnitude September 12 (2007)[22]
November 14, 2007, 7.7 magnitude, Antofagasta, Chile (2007).
November 29, 2007, 7.4 magnitude, Caribbean Sea (2007).
December 20, 2007 6.8 magnitude, Gisborne, New Zealand (2007).
February 20, 2008 Sumatra earthquake 7.5 magnitude[23]
February 25, 2008 Sumatra earthquake 7.3 magnitude. The quake was centered about 160 km (100 miles) south-southwest of Padang. The Pacific Tsunami Warning Center issued a local tsunami watch.[24]
March 21, 2008 China earthquake 7.2 magnitude. The quake happened in Yutian County, Xinjiang, a remote region in the Kunlun Mountains far from any residential areas.[25]
March 29, 2008 Sumatra earthquake 6.3 magnitude. The epicenter was about 175 miles (281 kilometers) south of Banda Aceh -- in a region hard-hit by the 2004 Indian Ocean earthquake. It could trigger a tsunami on coasts near its epicenter, the Pacific Tsunami Warning Center told.[26]
April 8, 2008 earthquake 7.5 magnitude. The quake was in the southern Pacific Ocean, about 85 kilometers southwest of Vanuatu.
May 12, 2008 earthquake 7.9 magnitude about 60 kilometers northwest of Chengdu in the Sichuan province in China, killed about 10,000 people, expected to soar.
[edit] Earthquakes in mythology and religion
In Norse mythology, earthquakes were explained as the violent struggling of the god Loki. When Loki, god of mischief and strife, murdered Baldr, god of beauty and light, he was punished by being bound in a cave with a poisonous serpent placed above his head dripping venom. Loki's wife Sigyn stood by him with a bowl to catch the poison, but whenever she had to empty the bowl the poison would drip on Loki's face, forcing him to jerk his head away and thrash against his bonds, causing the earth to tremble.[27]
In Greek mythology, Poseidon was the god of earthquakes.[28]
This article is about the natural seismic phenomenon. For other uses, see Earthquake (disambiguation).
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph. The moment magnitude of an earthquake is conventionally reported, or the related and mostly obsolete Richter magnitude, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.
At the Earth's surface, earthquakes manifest themselves by a shaking and sometimes displacement of the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.
In its most generic sense, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments.
An earthquake's point of initial rupture is called its focus or hypocenter. The term epicenter means the point at ground level directly above this.
Global earthquake epicenters, 1963–1998
Global plate tectonic movement
Contents[hide]
1 Naturally occurring earthquakes
2 Size and frequency of occurrence
3 Effects/impacts of earthquakes
3.1 Shaking and ground rupture
3.2 Landslides and avalanches
3.3 Fires
3.4 Soil liquefaction
3.5 Tsunami
3.6 Human impacts
4 Preparation for earthquakes
5 Specific fault articles
6 Major earthquakes
6.1 Pre-20th century
6.2 20th century
6.3 21st century
7 Earthquakes in mythology and religion
8 See also
9 References
10 External links
10.1 Educational
10.2 Seismological data centers
10.2.1 Europe
10.2.2 Japan
10.2.3 United States
10.3 Seismic scales
10.4 Scientific information
10.5 Miscellaneous
Naturally occurring earthquakes
Fault types
Most naturally occurring earthquakes are related to the tectonic nature of the Earth. Such earthquakes are called tectonic earthquakes. The Earth's lithosphere is a patchwork of plates in slow but constant motion caused by the release to space of the heat in the Earth's mantle and core. The heat causes the rock in the Earth to flow on geological timescales, so that the plates move slowly but surely. Plate boundaries lock as the plates move past each other, creating frictional stress. When the frictional stress exceeds a critical value, called local strength, a sudden failure occurs. The boundary of tectonic plates along which failure occurs is called the fault plane. When the failure at the fault plane results in a violent displacement of the Earth's crust, energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface, and cracking of the rock, thus causing an earthquake. This process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the Elastic-rebound theory. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth or is converted into heat generated by friction. Therefore, earthquakes lower the Earth's available elastic potential energy and raise its temperature, though these changes are negligible compared to the conductive and convective flow of heat out from the Earth's deep interior.[1]
The majority of tectonic earthquakes originate at depths not exceeding tens of kilometers. In subduction zones, where older and colder oceanic crust descends beneath another tectonic plate, Deep focus earthquakes may occur at much greater depths (up to seven hundred kilometers). These seismically active areas of subduction are known as Wadati-Benioff zones. These are earthquakes that occur at a depth at which the subducted lithosphere should no longer be brittle, due to the high temperature and pressure. A possible mechanism for the generation of deep focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure.[2]
Earthquakes also often occur in volcanic regions and are caused there, both by tectonic faults and by the movement of magma in volcanoes. Such earthquakes can serve as an early warning of volcanic eruptions.
Sometimes a series of earthquakes occur in a sort of earthquake storm, where the earthquakes strike a fault in clusters, each triggered by the shaking or stress redistribution of the previous earthquakes. Similar to aftershocks but on adjacent segments of fault, these storms occur over the course of years, and with some of the later earthquakes as damaging as the early ones. Such a pattern was observed in the sequence of about a dozen earthquakes that struck the North Anatolian Fault in Turkey in the 20th century, the half dozen large earthquakes in New Madrid in 1811-1812, and has been inferred for older anomalous clusters of large earthquakes in the Middle East and in the Mojave Desert.
[edit] Size and frequency of occurrence
This article may not provide balanced geographical coverage on a region.An editor has expressed concern that this article is biased. Please improve this article or discuss the issue on the talk page.
Minor earthquakes occur nearly constantly around the world in places like California and Alaska in the U.S., as well as in Chile, Peru, Indonesia, Iran, India the Azores in Portugal, New Zealand, Greece, Italy, and Japan,[3] Larger earthquakes occur less frequently, the relationship being exponential; for example, roughly ten times as many earthquakes larger than magnitude 4 occur in a particular time period than earthquakes larger than magnitude 5. In the (low seismicity) United Kingdom, for example, it has been calculated that the average recurrences are:
an earthquake of 3.7 - 4.6 every year
an earthquake of 4.7 - 5.5 every 10 years
an earthquake of 5.6 or larger every 100 years.
The number of seismic stations has increased from about 350 in 1931 to many thousands today. As a result, many more earthquakes are reported than in the past because of the vast improvement in instrumentation (not because the number of earthquakes has increased). The USGS estimates that, since 1900, there have been an average of 18 major earthquakes (magnitude 7.0-7.9) and one great earthquake (magnitude 8.0 or greater) per year, and that this average has been relatively stable.[4] In fact, in recent years, the number of major earthquakes per year has actually decreased, although this is likely a statistical fluctuation. More detailed statistics on the size and frequency of earthquakes is available from the USGS.[5]
Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000-km-long, horseshoe-shaped zone called the circum-Pacific seismic belt, also known as the Pacific Ring of Fire, which for the most part bounds the Pacific Plate.[6][7] Massive earthquakes tend to occur along other plate boundaries, too, such as along the Himalayan Mountains.
With the rapid growth of mega-cities such as Mexico City, Tokyo or Tehran, in areas of high seismic risk, some seismologists are warning that a single quake may claim the lives of up to 3 million people.[8][9][10]
Effects/impacts of earthquakes
1755 copper engraving depicting Lisbon in ruins and in flames after the 1755 Lisbon earthquake. A tsunami overwhelms the ships in the harbor.
Smoldering after the 1906 San Francisco earthquake.
Earthquake damage in Anchorage, Alaska (1964).
Earthquake damage in Mexico City (1985).
Earthquake damage in Armenia (1988).
A section of the Cypress viaduct collapsed during the Loma Prieta Earthquake (1989).
Kaiser Permanente Building destroyed in the Northridge Earthquake (1994).
Damage in Great Hanshin earthquake (1995) in Kobe, Japan.
Chūetsu earthquake (2004).
Please help improve this section by expanding it.Further information might be found on the talk page or at requests for expansion.
There are many effects of earthquakes including, but not limited to the following:
[edit] Shaking and ground rupture
Shaking and ground rupture are the main effects created by earthquakes, principally resulting in more or less severe damage to buildings or other rigid structures. The severity of the local effects depends on the complex combination of the earthquake magnitude, the distance from epicenter, and the local geological and geomorphological conditions, which may amplify or reduce wave propagation. The ground-shaking is measured by ground acceleration.
Specific local geological, geomorphological, and geostructural features can induce high levels of shaking on the ground surface even from low-intensity earthquakes. This effect is called site or local amplification. It is principally due to the transfer of the seismic motion from hard deep soils to soft superficial soils and to effects of seismic energy focalization owing to typical geometrical setting of the deposits.
Ground rupture is a visible breaking and displacement of the earth's surface along the trace of the fault, which may be of the order of few metres in the case of major earthquakes. Ground rupture is a major risk for large engineering structures such as dams, bridges and nuclear power stations and requires careful mapping of existing faults to identify any likely to break the ground surface within the life of the structure.
[edit] Landslides and avalanches
Earthquakes can cause landslides and avalanches, which may cause damage in hilly and mountainous areas.
[edit] Fires
Following an earthquake, fires can be generated by break of the electrical power or gas lines. In the event of water mains rupturing and a loss of pressure, it may also become difficult to stop the spread of a fire once it has started.
[edit] Soil liquefaction
Soil liquefaction occurs when, because of the shaking, water-saturated granular material temporarily loses its strength and transforms from a solid to a liquid. Soil liquefaction may cause rigid structures, as buildings or bridges, to tilt or sink into the liquefied deposits.
[edit] Tsunami
Undersea earthquakes and earthquake-triggered landslides into the sea, can cause Tsunami. See, for example, the 2004 Indian Ocean earthquake.
[edit] Human impacts
Earthquakes may result in disease, lack of basic necessities, loss of life, higher insurance premiums, general property damage, road and bridge damage, and collapse of buildings or destabilization of the base of buildings which may lead to collapse in future earthquakes.
[edit] Preparation for earthquakes
Earthquake preparedness
Household seismic safety
HurriQuake nail (for resisting hurricanes and earthquakes)
Seismic retrofit
Seismic hazard
Mitigation of seismic motion
Earthquake prediction
Pre-20th century
Pompeii (62).
Aleppo Earthquake (1138).
Basel earthquake (1356). Major earthquake that struck Central Europe in 1356.
Carniola earthquake (1511). A major earthquake that shook a large portion of South-Central Europe. Its epicenter was around the town of Idrija, in today's Slovenia. It caused great damage to structures all over Carniola, including Ljubljana, and in western Carinthia, particularly in Villach and Klagenfurt which were almost completely destroyed. There was some minor damage in Venice and other cities, too.
Shaanxi Earthquake (1556). Deadliest known earthquake in history, estimated to have killed 830,000 in China.
Dover Straits earthquake of 1580 (1580).
Dubrovnik earthquake (1667). Disastrous earthquake in Dubrovnik, Croatia killed about 3/5 of the population.
Port Royal Earthquake (1692). An earthquake on June 7, 1692, largely destroyed Port Royal, a safe harbor for pirates, causing two thirds of the city to sink into the Caribbean Sea.
The great Sicilian earthquake (1693). As many as 100,000 may have died.
Cascadia Earthquake (1700).
Tokyo earthquake (1703). 37,000 died.
Kamchatka earthquakes (1737) The third biggest earthquake on record measuring 9.3 on the richter scale.
Lisbon earthquake (1755), one of the most destructive and deadly earthquakes in history, killing between 60,000 and 100,000 people and causing a major tsunami that affected parts of Europe, North Africa and the Caribbean.
Calabria earthquake (1783). Series of 6 earthquakes in Calabria, Italy killed 50,000.[11]
Quito earthquake. (1797) Quito, Viceroyalty of Peru, now the capital of Ecuador, was devastated by an earthquake. 40,000 died.
New Madrid Earthquake (1811), and another tremor (1812) that also struck the small Missouri town, was reportedly the strongest ever in North America and made the Mississippi River temporarily change its direction and permanently altered its course in the region.
Fort Tejon Earthquake (1857). Estimated Richter Scale above 8, said the strongest earthquake in Southern California history.
Great Neapolitan Earthquake (1857). Estimated Richter Scale of 6.9. 11,000 dead.
1872 Lone Pine earthquake (1872). Might been strongest ever measured in California with an estimated Richter Scale of 8.1 said seismologists.
Charleston earthquake (1886). Largest earthquake in the southeastern United States, killed 100.
Ljubljana earthquake (14. IV. 1895), a series of powerful quakes that ultimately had a vital impact on the city of Ljubljana, being a catalyst of its urban renewal.
Assam earthquake of 1897 (1897). Large earthquake that destroyed all masonry structures, measuring more than 8 on the Richter scale.
20th century
San Francisco Earthquake (1906). Between 7.7 and 8.3 magnitudes; killed approximately 3,000 people and caused around $400 million in damage; most devastating earthquake in California and U.S. history.
Messina Earthquake (1908). Killed about 60,000 people.
Gansu earthquake (1920). Killed 200,000 in Gansu province, China.[12]
Great Kantō earthquake (1923). On the Japanese island of Honshū, killing over 140,000 in Tokyo and environs.
1931 Hawke's Bay earthquake. Occurred in the Hawkes Bay in the North Island of New Zealand leaving 256 dead.
1933 Long Beach earthquake
1935 Balochistan earthquake at Quetta, Pakistan measuring 7.7 on the Richter scale. Anywhere from 30,000 to 60,000 people died
1939 Erzincan earthquake at Erzincan, Turkey measuring 7.9 on the Richter scale.
Ashgabat earthquake (1948). Earthquake in Ashgabat, Soviet Union measuring 7.3 on the Richter scale killed over 110,000 (2/3 the population of the city).[13]
Assam earthquake of 1950 (1950). Earthquake in Assam, India measures 8.6M.
Kamchatka earthquakes (1952 and 1737), measuring >9.0.
Great Kern County earthquake (1952). This was second strongest tremor in Southern California history, epicentered 60 miles North of Los Angeles. Major damage in Bakersfield, California and Kern County, California, while it shook the Los Angeles area.
1959 Yellowstone earthquake, formed Quake Lake in southern Montana, USA
Great Chilean Earthquake (1960). Strongest earthquake ever recorded,[14] 9.5 on Moment magnitude scale, and generated tsunamis throughout the Pacific ocean. It measured 9.6 on the Richter scale. [15]
1960 Agadir earthquake, Morocco with around 15,000 casualties.
1963 Skopje earthquake, measuring 6.1 on the Richter scale kills 1,800 people, leaves another 120,000 homeless, and destroys 80% of the city.
Good Friday Earthquake (1964) In Alaska, it was the fourth biggest earthquake recorded,[16] measuring 9.2M. and generated tsunamis throughout the Pacific ocean.
Ancash earthquake (1970). Caused a landslide that buried the town of Yungay, Peru; killed over 40,000 people.
Sylmar earthquake (1971). Caused great and unexpected destruction of freeway bridges and flyways in the San Fernando Valley, leading to the first major seismic retrofits of these types of structures, but not at a sufficient pace to avoid the next California freeway collapse in 1989.
Managua earthquake (1972), which killed more than 10,000 people and destroyed 90% of the city. The earthquake took place on December 23, 1972 at midnight.
Friuli earthquake (1976), Which killed more than 2.000 people in Northeastern Italy and in the Slovenian Littoral on the 6th of May
Tangshan earthquake (1976). The most destructive earthquake of modern times. The official death toll was 255,000, but many experts believe that two or three times that number died.
Guatemala 1976 earthquake (1976). Causing 23,000 deaths, 77,000 injuries and the destruction of more than 250,000 homes.
Coalinga, California earthquake (1983). 6.5 on the Richter scale on a section of the San Andreas Fault. Six people killed, downtown Coalinga, California devastated and oil field blazes.
Great Mexican Earthquake (1985). Killed over 6,500 people, according to official Mexican government reports,[citation needed] but as many as 30,000 people are thought to have been killed (they disappeared and never reappeared after the initial Earthquakes).
Great San Salvador Earthquake (October 10, 1986). Killed over 1,500 people.
Whittier Narrows earthquake (1987).
1989 Newcastle earthquake, Australia
Armenian earthquake (1988). Killed over 25,000.
Loma Prieta earthquake (1989). Severely affecting Santa Cruz, San Francisco, San Jose and Oakland in California. This is also called the World Series Earthquake. It struck as Game 3 of the 1989 World Series was just getting underway at Candlestick Park in San Francisco. Revealed necessity of accelerated seismic retrofit of road and bridge structures.
Iran Earthquake (1990). 7.7 on the Richter scale. Killed over 35,000 in Gilan Province, southwest of Caspian sea.[17]
Luzon Earthquake (1990). On 16 July 1990, an earthquake measuring 7.7 on the Richter scale struck the island of Luzon, Philippines.
Landers, California earthquake (1992). Serious damage in the small town of Yucca Valley, California and was felt across 10 states in Western U.S. Another tremor measured 6.4 struck 3 hours later and felt across Southern California.
August 1993 Guam Earthquake, measuring 8.2 on the Richter scale and lasting 60 seconds.
Northridge, California earthquake (1994). Damage showed seismic resistance deficiencies in modern low-rise apartment construction.
Sakhalin earthquake (1995). Measuring 7.6 on the Richter scale, killing over 2,000 people in Sakhalin, Russia.[18]
Great Hanshin earthquake (1995). Killed over 6,400 people in and around Kobe, Japan.
1998 Afghanistan earthquake (1998). 6.9 on the Richter scale. Some 125 villages were damaged and 4000 people killed.[19]
Athens earthquake (1999). 5.9 on the Richter scale, it hit Athens on September 7. Epicentered 10 miles north of the Greek capital, it claimed 143 lives.
Chi-Chi earthquake (1999) Also called the 921 earthquake. Struck Taiwan on September 21, 1999. Over 2,000 people killed, destroyed or damaged over ten thousand buildings. Caused world computer prices to rise sharply.
Armenia, Colombia (1999) 6.2 on the Richter scale, Killed over 2,000 in the Colombian Coffee Grown Zone.
1999 İzmit earthquake measuring 7.5 on the Richter scale and killed over 17,000 in northwestern Turkey.
Hector Mine earthquake (1999). 7.1 on the Richter scale, epicentered 30 miles east of Barstow, California, widely felt in California and Nevada.
1999 Düzce earthquake at Düzce, Turkey measuring 7.2 on the Richter scale.
Baku earthquake (2000).
[edit] 21st century
Nisqually Earthquake (2001).
El Salvador earthquakes (2001). 7.9 (13 January) and 6.6 (13 February) magnitudes, killed more than 1,100 people.
Gujarat Earthquake (26 January 2001).
Hindu Kush earthquakes (2002). Over 1,100 killed.
Molise earthquake (2002) 26 killed.
Bam Earthquake (2003). Over 40,000 people are reported dead.
Parkfield, California earthquake (2004). Not large (6.0), but the most anticipated and intensely instrumented earthquake ever recorded and likely to offer insights into predicting future earthquakes elsewhere on similar slip-strike fault structures.
Chūetsu earthquake (2004).
Sumatra-Andaman Earthquake (26 December 2004). By some estimates, the second largest earthquake in recorded history (estimates of magnitude vary between 9.1[20] and 9.3). Epicentered off the coast of the Indonesian island of Sumatra, this massive earthquake triggered a series of gigantic tsunamis that smashed onto the shores of a number of nations, causing 230,000 fatalities.
Sumatran (Nias) Earthquake (2005).
Fukuoka earthquake (2005).
Northern Chile Earthquake (2005). 7.9 (13 June). Killed only 15 people, but left many poor families homeless.
Kashmir earthquake (2005) (also known as the Great Pakistan earthquake). Killed over 79,000 people; and many more injured.
Lake Tanganyika earthquake (2005).
May 2006 Java earthquake (2006).
July 2006 7.7 magnitude Java earthquake which triggered tsunamis (2006).
October 2006 6.6 magnitude Kona, Hawaii earthquake (2006).
November 2006 8.1 magnitude north of Japan (2006).
December 26, 2006, 7.2 magnitude, southwest of Taiwan (2006).
Sumatra Earthquakes March 06, 2007, 6.4 and 6.3 magnitude, Sumatra, Indonesia (2007).
March 25, 2007, 6.9 magnitude, off the west coast of Honshū, Japan (2007).
April 1, 2007, 8.1 magnitude, Solomon Islands (2007).
2007 Guatemala Earthquake 6.7 magnitude (2007).
July 16, 2007, 6.6 magnitude, Niigata prefecture, Japan (2007).
2007 Peru earthquake 8.0 magnitude, August 15 (2007)[21]
September 2007 Sumatra earthquakes 8.0 magnitude September 12 (2007)[22]
November 14, 2007, 7.7 magnitude, Antofagasta, Chile (2007).
November 29, 2007, 7.4 magnitude, Caribbean Sea (2007).
December 20, 2007 6.8 magnitude, Gisborne, New Zealand (2007).
February 20, 2008 Sumatra earthquake 7.5 magnitude[23]
February 25, 2008 Sumatra earthquake 7.3 magnitude. The quake was centered about 160 km (100 miles) south-southwest of Padang. The Pacific Tsunami Warning Center issued a local tsunami watch.[24]
March 21, 2008 China earthquake 7.2 magnitude. The quake happened in Yutian County, Xinjiang, a remote region in the Kunlun Mountains far from any residential areas.[25]
March 29, 2008 Sumatra earthquake 6.3 magnitude. The epicenter was about 175 miles (281 kilometers) south of Banda Aceh -- in a region hard-hit by the 2004 Indian Ocean earthquake. It could trigger a tsunami on coasts near its epicenter, the Pacific Tsunami Warning Center told.[26]
April 8, 2008 earthquake 7.5 magnitude. The quake was in the southern Pacific Ocean, about 85 kilometers southwest of Vanuatu.
May 12, 2008 earthquake 7.9 magnitude about 60 kilometers northwest of Chengdu in the Sichuan province in China, killed about 10,000 people, expected to soar.
[edit] Earthquakes in mythology and religion
In Norse mythology, earthquakes were explained as the violent struggling of the god Loki. When Loki, god of mischief and strife, murdered Baldr, god of beauty and light, he was punished by being bound in a cave with a poisonous serpent placed above his head dripping venom. Loki's wife Sigyn stood by him with a bowl to catch the poison, but whenever she had to empty the bowl the poison would drip on Loki's face, forcing him to jerk his head away and thrash against his bonds, causing the earth to tremble.[27]
In Greek mythology, Poseidon was the god of earthquakes.[28]
Tuesday, February 12, 2008
Are Mobile Telephone Communication Antennas a Health Hazard?
Is the radiation from mobile phone base station antennas a health hazard?
Introduction:
There are mobile phone base station antennas on towers and buildings throughout Australia’s metropolitan areas. These antennas are part of the mobile (or cellular) telephone network and they emit radiofrequency (RF) radiation. This fact sheet provides information about the possibility of adverse health effects arising from exposure to this radiation.
Current research indicates that no adverse health effects should be expected from exposure to the RF radiation from mobile phone base station antennas. Read on for more detail.
Antenna Description and Operation
When a call is made from a mobile telephone, RF signals are transmitted between its antenna and the antenna at a nearby base station. The telephone call is then routed through telephone network (cable or radio) to the destination telephone.
Mobile telephones emit signals at the frequency of around 800 MHz for the CDMA (Code Division Multiple Access) network, 900 & 1800 MHz for the GSM (Global System for Mobile Communication) network and 2100 MHz for the 3G network. These signals are picked up by antennas which are on the towers. The signals may also be transmitted between base stations and are in a higher frequency range, 15 to 23 gigahertz, and radiated as a very narrow beam by dish shaped antennas, also mounted near the top of the tower.
Radio Frequency Radiation
RF radiation, as well as ultraviolet radiation, visible light, infrared radiation and power frequency fields, are types of non-ionising radiation. These radiations, together with ionising electromagnetic radiation (X radiation and gamma radiation) make up the electromagnetic spectrum (Download a chart (PDF 384kb) of the electromagnetic spectrum).
When ionising radiations collide with biological material, they create positively and negatively charged particles, which may have adverse effects. Non-ionising radiations cannot create such particles. As far as is currently known, RF radiation, for example, can only cause the molecules in biological material to vibrate and thereby generate heat.
Exposure Levels and Recommended Limits
The exposure levels of RF radiation are measured in microwatts per square centimeter (abbreviated as μW/cm2). One μW is a millionth of a watt. The maximum exposure levels measured adjacent to the base station towers are less than 2 μW/cm2. The exposure level decreases with increasing distance from the base of the tower.
These levels can be compared with 450 μW/cm2, which is the exposure limit at 900MHz for members of the public (that is, unlimited exposure duration) recommended by the ARPANSA Radiation Protection Standard - "Maximum exposure levels to radiofrequency fields - 3kHz to 300GHz"
Health Effects
Current research indicates that, at the exposure levels indicated above, RF radiation is not known to have any adverse health effects.
It is considered that rises in tissue or body temperature of about 1.0 oC or more are required before any adverse effects will occur. In cases of pregnancy, rises in the temperature of the foetus of 2.5 to 5 oC are necessary before defects are seen in the newborn. These temperature rises will not occur unless the exposure level is greatly in excess of the Australian Standard mentioned above. Exposure to the low level of RF radiation emitted from base station antennas will not, in fact, cause any noticeable temperature rise.
There are many reports in the literature of research on non-thermal effects, usually of a subjective nature. Studies that have investigated if RF radiation affects biological cells, other than by heating them, are inconclusive. In addition, the exposure levels used in these studies are higher than those mentioned above.
The present concern that people have about RF exposure is whether these non-thermal effects also include cancer. While human studies to assess the possibility that RF exposure increases the risk of cancer are few in number, laboratory studies do not provide evidence to support the notion that RF fields cause cancer. Review groups evaluating the state of knowledge about possible links between RF exposure and excess risk of cancer have concluded that there is no clear evidence for any links. The Australian Radiation Protection and Nuclear Safety Agency continues to closely monitor the research being conducted in this field.
Conclusion
No adverse health effects are expected from continuous exposure to the RF radiation emitted by the antennas on mobile telephone base station towers.
Introduction:
There are mobile phone base station antennas on towers and buildings throughout Australia’s metropolitan areas. These antennas are part of the mobile (or cellular) telephone network and they emit radiofrequency (RF) radiation. This fact sheet provides information about the possibility of adverse health effects arising from exposure to this radiation.
Current research indicates that no adverse health effects should be expected from exposure to the RF radiation from mobile phone base station antennas. Read on for more detail.
Antenna Description and Operation
When a call is made from a mobile telephone, RF signals are transmitted between its antenna and the antenna at a nearby base station. The telephone call is then routed through telephone network (cable or radio) to the destination telephone.
Mobile telephones emit signals at the frequency of around 800 MHz for the CDMA (Code Division Multiple Access) network, 900 & 1800 MHz for the GSM (Global System for Mobile Communication) network and 2100 MHz for the 3G network. These signals are picked up by antennas which are on the towers. The signals may also be transmitted between base stations and are in a higher frequency range, 15 to 23 gigahertz, and radiated as a very narrow beam by dish shaped antennas, also mounted near the top of the tower.
Radio Frequency Radiation
RF radiation, as well as ultraviolet radiation, visible light, infrared radiation and power frequency fields, are types of non-ionising radiation. These radiations, together with ionising electromagnetic radiation (X radiation and gamma radiation) make up the electromagnetic spectrum (Download a chart (PDF 384kb) of the electromagnetic spectrum).
When ionising radiations collide with biological material, they create positively and negatively charged particles, which may have adverse effects. Non-ionising radiations cannot create such particles. As far as is currently known, RF radiation, for example, can only cause the molecules in biological material to vibrate and thereby generate heat.
Exposure Levels and Recommended Limits
The exposure levels of RF radiation are measured in microwatts per square centimeter (abbreviated as μW/cm2). One μW is a millionth of a watt. The maximum exposure levels measured adjacent to the base station towers are less than 2 μW/cm2. The exposure level decreases with increasing distance from the base of the tower.
These levels can be compared with 450 μW/cm2, which is the exposure limit at 900MHz for members of the public (that is, unlimited exposure duration) recommended by the ARPANSA Radiation Protection Standard - "Maximum exposure levels to radiofrequency fields - 3kHz to 300GHz"
Health Effects
Current research indicates that, at the exposure levels indicated above, RF radiation is not known to have any adverse health effects.
It is considered that rises in tissue or body temperature of about 1.0 oC or more are required before any adverse effects will occur. In cases of pregnancy, rises in the temperature of the foetus of 2.5 to 5 oC are necessary before defects are seen in the newborn. These temperature rises will not occur unless the exposure level is greatly in excess of the Australian Standard mentioned above. Exposure to the low level of RF radiation emitted from base station antennas will not, in fact, cause any noticeable temperature rise.
There are many reports in the literature of research on non-thermal effects, usually of a subjective nature. Studies that have investigated if RF radiation affects biological cells, other than by heating them, are inconclusive. In addition, the exposure levels used in these studies are higher than those mentioned above.
The present concern that people have about RF exposure is whether these non-thermal effects also include cancer. While human studies to assess the possibility that RF exposure increases the risk of cancer are few in number, laboratory studies do not provide evidence to support the notion that RF fields cause cancer. Review groups evaluating the state of knowledge about possible links between RF exposure and excess risk of cancer have concluded that there is no clear evidence for any links. The Australian Radiation Protection and Nuclear Safety Agency continues to closely monitor the research being conducted in this field.
Conclusion
No adverse health effects are expected from continuous exposure to the RF radiation emitted by the antennas on mobile telephone base station towers.
Friday, February 8, 2008
Cordless phones: the unspoken DECT hazard at home and at work
Cordless phones: the unspoken DECT hazard at home and at work
Why talk about DECT phones on a TETRA website? One main reason is to help determine causes of symptoms that might be attributed falsely to TETRA. We have heard and found many reports of similar adverse symptoms that are more likely to be caused by DECT (Digital Electronic Cordless Telephones), and indeed that have been eliminated by stopping using these phones. You will be unaware of what they do, but if you have one, read the following carefully. Many people will be equally unaware of neighbours using DECT, whose pulses penetrate right through their walls. DECT comes with no guidance and no health warnings. This must be wrong.
About DECT Cordless Telephones
All modern (DECT) digital cordless phones emit the same type of pulsed microwave radiation (about 1.8 GHz) as ordinary (GSM) mobile phones. Emissions can be about 6 V/m within a metre of the base unit, for as long as it is plugged in. These base stations emit their radiation even when the phone is not in use. All DECT base units emit microwaves continuously 24 hours a day as long as they are plugged in. For this reason cordless phones are regarded as bad news. The latest Lennart Hardell paper on mobile phone use and brain tumours (× 3 for 5 years use and × 3 to 4 for 10 years use) also show a dose response increased brain cancer risk for long-term (over 5 years) regular cordless phone use. A DECT phone is a mobile phone, and its base is a mobile phone mast in your house or office. You must use one? Keep the base unit and remote extra handsets away from where you sit or sleep, and remember that you are transmitting into neighbouring property through your walls.
Unlike mobile phones, DECT cordless phones work at a fixed power. Mobiles turn their power down to the lowest level possible, so when you are near a base station this can be much lower than a DECT cordless. DECT pulses are far more aggressive than for mobiles.
Note: DECT phones are now being manufactured and available in Germany, and now in the UK that only transmit from the base when the handset is lifted. Of course, these are not sold as a ‘safer’ variety, but as ‘lower emission’. Lower emissions matter to the more wary manufacturers, who nevertheless claim that there is not much demand. They are safer – to everyone. But don’t be deceived, the handset is still a GSM mobile phone. Read on ...
Orchid have are now producing their 3rd generation ‘low radiation’ DECT cordless phones – their main advantages over the previous models are:
There are no microwave emissions when the phone is not being used. When a call is ended both the phone and the base station go into ‘sleep mode’ (no microwave radiation) until either a call is received or made. There is no need to return the handset back to the base station for ‘sleep mode’ to become operative.
The phone/base station adjust their power output depending on how far away the base station is from the handset. It you make a call up to several meters from the base station power output is reduced by as much as 75%.
Rowtex Limited has now taken over the sales and distribution of all Orchid Low Radiation phones.
Mobile phone concerns
A team led by Professor Kjell Mild, a Swedish biophysicist, who has produced a number of many leading mobile-phone health effects papers has published an update on his brain-tumour work in the summer of 2001, when he discussed his results to date at an international conference chaired by Alasdair Philips of Powerwatch.
Another study by Dr Lennart Hardell, published in the International Journal of Oncology, was based on the analysis of 1,600 tumour victims who had been using mobile phones for up to 10 years before being diagnosed. Prof. Mild now states: ‘The evidence for a connection between phone use and cancer is clear and convincing. The more you use phones and the greater the number of years you have them, the greater the risk of brain tumours. ... Mobile phones are here to stay so my advice is never to use one without a hands-free headset.’
An earlier study by Mild, a cancer specialist, linked brain tumours to the use of analogue mobile phones. The new research repeated this and also looked at digital mobiles and DECT cordless phones. It showed that all three types were linked with increased tumour rates. The extra tumours only start to really show up after about 5 years use, but there is increasing dose-related-response with minutes of use per month and number of years of use.
Since 1980, the number of acoustic neuromas (a rare tumour) diagnosed in Britain has risen from one in every 100,000 of the population to one in 80,000 a year. Some (but not all) other types of tumour also show an increase.
Dr Richard Sullivan, head of clinical programmes at Cancer Research UK and quoted in the Sunday Times on 16th March 2003, said the study was worrying. ‘It suggests a strong link between mobile phones and brain tumours. We now need a full-scale study.’
On 14 October a study by the Karolinska Institute in Sweden found a pronounced risk of acoustic nuroma (cancer) from use of mobile phones over a ten year period (imagine: aged just from 14 to 24: ages of many big users of mobile phones).
DECT pulse frequency concern
It is important to put out a warning about DECT phones, as they could be up to 100 times worse than an ordinary mobile, particularly if used in built up areas. The reason for this is the frequency of the pulse. DECT pulses at 100Hz whilst a GSM mobile pulses at 217Hz. Remember, the lower the pulsing frequency, the stronger the biological effect. It’s the pulsing within the ELF (extremely low frequency) range we have to be concerned about. That’s why TETRA is so dangerous. It pulses at 17.6Hz, right within the human beta brainwave rhythm range. Dr von Klitzing, who was one of the Medical Physicists signing the Freiburger Appeal, reported his research regarding DECT phones. His research on blood samples taken from children in the vicinity of DECT phones showed that the red blood corpuscles did not ‘ripen out properly’ (a direct translation of his words). The physical signs were: listlessness and/or aggression, pallor, sleeplessness etc. This could be reversed with the removal of the phone.
Choice
In your own home you have a choice, and it is yours. If you have reservations as a result of reading up on DECT, at least revert to an older style analogue cordless phone – or put up with wires!
Neighbours’ phones are another matter. If you know where such a phone base is, you may decide to try foil on the wall in a large patch, to screen the DECT out. If it works, you might prefer to install it more permanently under wallpaper. But do note that microwaves tend to run around such barriers like water around a stone in a stream, so a small phone-sized patch will not work. (Findings from using an Acousticom detector.)
If you find your foil disrupts the neighbouring phone, you don’t want to get into a dispute, with one of you moving the phone and the other moving the screen. Try and explain the problem in an open way, using the research listed here.
DECT in the office? Again an emotive subject. All your employer will do is refer to the Health and Safety Executive, who refer to the NRPB, who cite the ICNIRP (if it doesn’t heat you it can’t harm you) guidelines. These are wholly inappropriate, so employees have (a) no guidance and (b) no way to assess exposure in the office. The manufacturers give no advice on density of DECT per square metre. If you are sensitive to DECT, try to explain what you experience and ask for a wired phone. But I know it may not be easy.
Signs of change
One might ask why, if there is absolutely nothing to worry about from such a small radiation source as DECT, there has been such medical concern, and now, industry response. Here is a press notice ‘DECT – radiation source in the dwelling’ from the German Bundesamot für Strahlenschutz (Federal Office for Radiation Protection) [translation]. The issue is that DECT does not need to transmit continuously. And so a new DECT is being manufactured in Germany that does not transmit continuously, and only as required. In fact it is so popular, they cannot make them fast enough.
Why talk about DECT phones on a TETRA website? One main reason is to help determine causes of symptoms that might be attributed falsely to TETRA. We have heard and found many reports of similar adverse symptoms that are more likely to be caused by DECT (Digital Electronic Cordless Telephones), and indeed that have been eliminated by stopping using these phones. You will be unaware of what they do, but if you have one, read the following carefully. Many people will be equally unaware of neighbours using DECT, whose pulses penetrate right through their walls. DECT comes with no guidance and no health warnings. This must be wrong.
About DECT Cordless Telephones
All modern (DECT) digital cordless phones emit the same type of pulsed microwave radiation (about 1.8 GHz) as ordinary (GSM) mobile phones. Emissions can be about 6 V/m within a metre of the base unit, for as long as it is plugged in. These base stations emit their radiation even when the phone is not in use. All DECT base units emit microwaves continuously 24 hours a day as long as they are plugged in. For this reason cordless phones are regarded as bad news. The latest Lennart Hardell paper on mobile phone use and brain tumours (× 3 for 5 years use and × 3 to 4 for 10 years use) also show a dose response increased brain cancer risk for long-term (over 5 years) regular cordless phone use. A DECT phone is a mobile phone, and its base is a mobile phone mast in your house or office. You must use one? Keep the base unit and remote extra handsets away from where you sit or sleep, and remember that you are transmitting into neighbouring property through your walls.
Unlike mobile phones, DECT cordless phones work at a fixed power. Mobiles turn their power down to the lowest level possible, so when you are near a base station this can be much lower than a DECT cordless. DECT pulses are far more aggressive than for mobiles.
Note: DECT phones are now being manufactured and available in Germany, and now in the UK that only transmit from the base when the handset is lifted. Of course, these are not sold as a ‘safer’ variety, but as ‘lower emission’. Lower emissions matter to the more wary manufacturers, who nevertheless claim that there is not much demand. They are safer – to everyone. But don’t be deceived, the handset is still a GSM mobile phone. Read on ...
Orchid have are now producing their 3rd generation ‘low radiation’ DECT cordless phones – their main advantages over the previous models are:
There are no microwave emissions when the phone is not being used. When a call is ended both the phone and the base station go into ‘sleep mode’ (no microwave radiation) until either a call is received or made. There is no need to return the handset back to the base station for ‘sleep mode’ to become operative.
The phone/base station adjust their power output depending on how far away the base station is from the handset. It you make a call up to several meters from the base station power output is reduced by as much as 75%.
Rowtex Limited has now taken over the sales and distribution of all Orchid Low Radiation phones.
Mobile phone concerns
A team led by Professor Kjell Mild, a Swedish biophysicist, who has produced a number of many leading mobile-phone health effects papers has published an update on his brain-tumour work in the summer of 2001, when he discussed his results to date at an international conference chaired by Alasdair Philips of Powerwatch.
Another study by Dr Lennart Hardell, published in the International Journal of Oncology, was based on the analysis of 1,600 tumour victims who had been using mobile phones for up to 10 years before being diagnosed. Prof. Mild now states: ‘The evidence for a connection between phone use and cancer is clear and convincing. The more you use phones and the greater the number of years you have them, the greater the risk of brain tumours. ... Mobile phones are here to stay so my advice is never to use one without a hands-free headset.’
An earlier study by Mild, a cancer specialist, linked brain tumours to the use of analogue mobile phones. The new research repeated this and also looked at digital mobiles and DECT cordless phones. It showed that all three types were linked with increased tumour rates. The extra tumours only start to really show up after about 5 years use, but there is increasing dose-related-response with minutes of use per month and number of years of use.
Since 1980, the number of acoustic neuromas (a rare tumour) diagnosed in Britain has risen from one in every 100,000 of the population to one in 80,000 a year. Some (but not all) other types of tumour also show an increase.
Dr Richard Sullivan, head of clinical programmes at Cancer Research UK and quoted in the Sunday Times on 16th March 2003, said the study was worrying. ‘It suggests a strong link between mobile phones and brain tumours. We now need a full-scale study.’
On 14 October a study by the Karolinska Institute in Sweden found a pronounced risk of acoustic nuroma (cancer) from use of mobile phones over a ten year period (imagine: aged just from 14 to 24: ages of many big users of mobile phones).
DECT pulse frequency concern
It is important to put out a warning about DECT phones, as they could be up to 100 times worse than an ordinary mobile, particularly if used in built up areas. The reason for this is the frequency of the pulse. DECT pulses at 100Hz whilst a GSM mobile pulses at 217Hz. Remember, the lower the pulsing frequency, the stronger the biological effect. It’s the pulsing within the ELF (extremely low frequency) range we have to be concerned about. That’s why TETRA is so dangerous. It pulses at 17.6Hz, right within the human beta brainwave rhythm range. Dr von Klitzing, who was one of the Medical Physicists signing the Freiburger Appeal, reported his research regarding DECT phones. His research on blood samples taken from children in the vicinity of DECT phones showed that the red blood corpuscles did not ‘ripen out properly’ (a direct translation of his words). The physical signs were: listlessness and/or aggression, pallor, sleeplessness etc. This could be reversed with the removal of the phone.
Choice
In your own home you have a choice, and it is yours. If you have reservations as a result of reading up on DECT, at least revert to an older style analogue cordless phone – or put up with wires!
Neighbours’ phones are another matter. If you know where such a phone base is, you may decide to try foil on the wall in a large patch, to screen the DECT out. If it works, you might prefer to install it more permanently under wallpaper. But do note that microwaves tend to run around such barriers like water around a stone in a stream, so a small phone-sized patch will not work. (Findings from using an Acousticom detector.)
If you find your foil disrupts the neighbouring phone, you don’t want to get into a dispute, with one of you moving the phone and the other moving the screen. Try and explain the problem in an open way, using the research listed here.
DECT in the office? Again an emotive subject. All your employer will do is refer to the Health and Safety Executive, who refer to the NRPB, who cite the ICNIRP (if it doesn’t heat you it can’t harm you) guidelines. These are wholly inappropriate, so employees have (a) no guidance and (b) no way to assess exposure in the office. The manufacturers give no advice on density of DECT per square metre. If you are sensitive to DECT, try to explain what you experience and ask for a wired phone. But I know it may not be easy.
Signs of change
One might ask why, if there is absolutely nothing to worry about from such a small radiation source as DECT, there has been such medical concern, and now, industry response. Here is a press notice ‘DECT – radiation source in the dwelling’ from the German Bundesamot für Strahlenschutz (Federal Office for Radiation Protection) [translation]. The issue is that DECT does not need to transmit continuously. And so a new DECT is being manufactured in Germany that does not transmit continuously, and only as required. In fact it is so popular, they cannot make them fast enough.
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