A magnitude 5.9 earthquake has struck the east coast of the United States.
The quake was felt in Washington, where the Pentagon and US Capitol Building were evacuated, as well as in New York.
There were no immediate reports of any major damage or injuries.
The US eastern seaboard has few larger earthquakes. Many workers were bewildered -- and feared the worst -- as their desks swayed violently and their ceilings and walls shook.
Thousands of people across the US East Coast raced frantically into the streets Tuesday as an earthquake sent shock waves of the kind last seen almost exactly a decade ago on September 11
In a region days away from commemorating the trauma of the September 11, 2001 attacks, many immediately suspected terrorism as they raced down stairways to parks and street corners.
Many people in parks asked one another where they were on September 11, 2001. But unlike 10 years ago, the mood was more festive as people learned that there was little major damage.
Several bars in Washington smelled a business opportunity and declared earthquake happy hours for residents who did not want to brave the commuter crowds -- or who were suddenly given the afternoon off.
Many major institutions from schools to the Smithsonian museums closed for the day, some in hopes of easing pressure on commuters. Mass-transit systems around Washington, Baltimore and Philadelphia reported major delays, though trains ran closer to schedule in the New York area.
A 7.1-magnitude earthquake struck the central coastal area of Chile on Sunday, some 70 kilometers (45 miles) northwest of Temuco, the U.S. Geological Survey said. There were no immediate reports of major damage or injury.
The quake, which stuck around 5:20 p.m. (3:20 p.m. ET), was felt as far away as Santiago, roughly 595 km (370 miles) north of where the USGS said the quake occurred. The epicenter was more than 10 miles underground, the USGS said.
Loreto Henriquez, manager of the Holiday Inn Express in Temuco, felt the quake for about a minute, describing it as loud and strong. She said people ran into the streets, but did not report any major damage.
Earthquake preparedness is high around seismically active tectonic plate boundaries, often saving many lives and structures. Quake death rates within continental interiors are higher than that of continental plate boundaries. Their faults are often very complex and slow-moving, sometimes taking thousands of years to rupture.
Knowledge of seismic risk is badly skewed in favor of earthquakes that occur on plate boundaries, such as the March 11 temblor that hit northeast Japan, rather than those that strike deep inland, a pair of scientists said on Sunday.
In commentary appearing in the journal Nature Geoscience, Philip England of Oxford University and James Jackson of Cambridge University say that in seismic terms, the 9.0-magnitude Sendai quake was "a remarkable story of resilience."
Good civic training and building construction meant that the death rate was "impressively low," they said. Around 25,000 people died, or 0.4 percent of those exposed to the event, and most of these died from the tsunami that followed.
The March 11 event occurred on a plate boundary, where the jigsaw of plates that float on Earth's crust jostle and grind and slide under each other.
England and Jackson say plate boundaries are relatively well-studied, but a far greater threat lurks in continental inland areas.
"Death rates in earthquakes within continental interiors have often exceeded five percent and can be as high as 30 percent," they warn.
According to their count, over the past 120 years, there have been around 130 quakes around the world where a thousand people or more have died.
Of these, about 100 have occurred in continental interiors, causing 1.4 million deaths, whereas earthquakes at plate boundaries have inflicted 800,000 deaths, roughly half of them by tsunamis.
Among the inland killers were those in Bam, Iran, which cost 30,000 lives in 2003; in Muzzafarabad, Pakistan, which led to 75,000 deaths in 2005; and the 2008 Wenchuan quake in China in 2008 in which 70,000 died.
The main reason for these high tolls is because inland quake zones are poorly mapped, the commentary says.
Their faults are often very complex and slow-moving, sometimes taking hundreds or even thousands of years to build up tension to the point where they rupture.
Jackson and England call for the study of inland faults to be given the same priority as boundary faults, starting with the 10 million square kilometers (3.86 million sq. miles) of the Alpine-Himalayan belt, which stretches from Italy, Greece and Turkey, across the Middle East, Iran and central Asia, to China.
"The severity of this threat is increasing rapidly as millions of people every year migrate into mega-cities in vulnerable locations, many of which were devastated by earthquakes in the past, when their populations were much smaller."
Grimsvoetn volcano, located beneath Iceland's Vatnajoekull glacier, last erupted in 2004. Last year, Iceland's Eyjafjoell volcano, southwest of Grimsvoetn, shut down large swathes of European airspace for almost a month. For now, it is not known if Grimsvoetn will produce the troublesome fine ash Eyjafjoell generated.
The Grimsvoetn volcano under Iceland's largest glacier began erupting Saturday, the Icelandic Meteorological Office said, reporting a tall plume of smoke rising from the crater.
"An eruption at Grimsvoetn has started and there's an airplane on its way there now to investigate further," Haraldur Eirkisson of the office told AFP.
"There was a cloud rising up from Grimsvoetn around 1900 GMT and at just before 2000 GMT it had reached an altitude of 11 kilometers (6.8 miles)," he added.
Another meteorologist at the same office, Fridjon Magnusson, told AFP less than two hours later that the column of smoke had swelled to reach an altitude of 20 kilometers.
Grimsvoetn is Iceland's most active volcano, having erupted nine times between 1922 and 2004. It lies beneath the Vatnajoekull glacier in the southeast of the North Atlantic island nation.
The eruption in April last year of Iceland's Eyjafjoell volcano, southwest of Grimsvoetn, shut down large swathes of European airspace for almost a month amid fears the volcanic ash could wreak havoc on aircraft engines.
No two volcanic eruptions are the same, and it remained unclear late Saturday if the new eruption threatened to emit a similar kind of ash -- fine, with very sharp particles -- like the massive plume that burst from Eyjafjoell.
"The eruption has not yet spread very far, and is still looming over the Vatnajoekull glacier," Magnusson pointed out.
"These are just the first few hours of the eruption. We can't say yet whether this will have an effect on air traffic like Eyjafjoell," he added.
The problem with last year's eruption, which caused the planet's biggest air space shutdown since World War II, was according to the researchers that it happened under a glacier, bursting through 200-300 meters of ice.
It was the "interaction between the cold water and the hot magma that made the particles really tiny," and therefore especially dangerous to aircraft, Susan Stipp, a professor at the Nano-Science Centre at the University of Copenhagen, told AFP late last month.
"The (ash) particles were small so they went high and far. They were sharp, so they were a danger to airplane windows. It's like sand-blasting the airplane. And they were small and could melt at temperatures common in jet engines ... and could cause failure," she told AFP.
While Saturday's eruption had sent smoke high in the sky, Magnusson pointed out that there so far was only "heavy ash at the bottom of the bloom (that) has not reached high heights."
Bjarni Steinthorsson, a farmer who lives near the Vatnajoekull glacier, meanwhile told the Morgunbladid daily's website small amounts of ash had begun falling in the area and "the snow is getting darker."
He said that he expected more ash to fall overnight, although what happened would depend on the direction of the winds, which were currently almost still at the eruption site.
Iceland's State Road Authority meanwhile announced late Saturday it had temporarily closed a road near the glacier that is part of the national highway system.
Grimsvoetn is also located under a glacier, in an enormous, eight-kilometer (five-mile) diameter caldera -- a collapsed volcanic crater -- near the center of the Vatnajoekull icefield.
When it last erupted in November 2004, volcanic ash fell as far away as mainland Europe and caused minor disruptions in flights to and from Iceland.
Geologists had worried late last year the volcano was about to blow when they noticed a large river run caused by rapidly melting glacier ice.
Eruptions at Grimsvoetn traditionally result in massive flooding, although this has little impact since the surrounding areas are uninhabited.
Ash from an erupting Icelandic volcano could reach northern Scotland by Tuesday and parts of Britain, France and Spain by Thursday or Friday if the eruption continues at the same rate, airlines were warned on Sunday.
The warning is based on latest 5-day weather forecasts, but must be treated with caution because of the forecast period and the presence of different air currents from those prevailing at the time of last year's ash crisis, weather officials said.
European authorities said on Sunday no disruption was expected to European or transatlantic airspace over the next 24 hours from the eruption of Iceland's most active volcano on Saturday.
The warning comes nearly a year after one volcano erupted in Iceland and caused havoc for air passengers.
Grimsvoetn, Iceland’s most active volcano at the heart of its biggest glacier, began erupting late on Saturday, sending a plume of smoke and ash 12miles high.
So much ash was blasted into the sky that it blocked out the sun and covered nearby villages and farms.
Iceland has closed its main international airport and cancelled domestic flights after its most active volcano, Grimsvotn, began erupting.
A plume of smoke has risen 20km (12 miles) into the sky from the volcano.
But Iceland's Meteorological Office says the eruption should not cause widespread disruption to air traffic.
Last year, ash clouds from another Icelandic volcano, Eyjafjallajokul, led to the closure of a large section of European airspace.
Governments feared that ash particles could cause aircraft engines to fail, and the closure caused chaos to air travellers. Different ash Hjordis Gudmundsdottir, a spokeswoman for the Isavia civil aviation authority said: "We have closed the area until we know better what effect the ash will have."
The authority said Keflavik airport, the country's main hub, would remain shut for the rest of Sunday.
But officials say the eruption is unlikely to have the same impact as Eyjafjallajokul in 2010.
University of Iceland geophysicist Magnus Tumi Gudmundsson said this was Grimsvotn's largest eruption for 100 years, "much bigger and more intensive than Eyjafjallajokull".
He added: "There is a very large area in south-east Iceland where there is almost total darkness and heavy fall of ash. But it is not spreading nearly as much. The winds are not as strong as they were in Eyjafjallajokull."
He said this ash was coarser than last year's eruption, falling to the ground more quickly instead of floating long distances.
Europe's air traffic control organisation said on Sunday: "There is currently no impact on European or trans-Atlantic flights and the situation is expected to remain so for the next 24 hours.
"Aircraft operators are constantly being kept informed of the evolving situation." Threat to engines Grimsvotn lies under the the largest glacier in Europe, Vatnajokull in south-east Iceland.
When it last erupted in 2004, transatlantic flights had to be re-routed south of Iceland, but no airports were closed.
Last year's outpouring of ash from Eyjafjallajokull led to the largest closure of European airspace since World War II.
About 10 million travellers were affected and some questioned whether the shutdown was an over-reaction.
However, a scientific study published last month said the safety concerns had been well founded.
Researchers from the University of Copenhagen and the University of Iceland said ash particles from the early part of the Eyjafjallajokull eruption were especially abrasive, posing a possible threat to aircraft engines.
ScienceDaily (Apr. 8, 2011) — Researchers at the Institute of Geomatics -- Research Centre of the Polytechnic University of Catalonia (UPC) and the Government of Catalonia -- have estimated the ground deformation suffered in the area of Sendai, Japan, as a consequence of the earthquake of March 11, 2011 and its aftershocks. The estimate was derived from radar observations acquired by the Envisat satellite of the European Space Agency. According to this estimate, obtained over an area of approximately 300 x 100 km around the city of Sendai, the terrain has suffered a co-seismic deformation -- permanent deformation of Earth's surface -- associated with the earthquake of up to 1.69 m.
This value refers to the line connecting the satellite and the observed area, which is tilted about 41º from the vertical. The estimated value of 1.69 m is a deformation value relative to the observed area: the absolute deformation (i.e., calculated over an area not affected by the earthquake) is surely larger and cannot be estimated with this technique.
The minimum distance from the epicentre to the study area is 100 km approximately. At these distances the vast majority of earthquakes do not cause co-seismic deformation. However, in this case, there has been considerable deformation due to the exceptional magnitude of this earthquake.
The deformation can be seen in the map shown above, where the displacements are represented in a colour scale from black (no relative motion) to red (area of maximum deformation, which is the closest to the epicentre). There is relative deformation of 1.69 m from the area that appears black to the maximum area in red.
This study conducted by the Institute of Geomatics, and led by Dr. Michele Crosetto, head of the Remote Sensing Unit, is based on a well-known satellite-based microwave remote sensing technique called differential interferometry SAR (Synthetic Aperture Radar).
What does the observed deformation entail?
As mentioned above, the estimated 1.69 m deformation refers to the line connecting the satellite and the observed area. We know from other sources, such as measures of GPS (Global Positioning System), that the horizontal displacement has been of approximately 3 m eastwards, 0.5 m northwards and the vertical displacement varies between 0.5 and 1 m. The most important of these three components is probably the subsidence as it affects land elevation above sea level. Coastal areas are likely to be the most affected: in the worst case scenario, subsidence might lead to land loss. This is a phenomenon similar to what might result from climate change, although in this case, land would be lost as a result of sea-level rise.
How were the results derived?
SAR interferometry is a remote sensing technique used to monitor surface deformations. This technique, based on the analysis of SAR satellite data, has been used in various applications such as studying the dynamics of glaciers, earthquakes, volcanoes, mining, civil works, landslides and deformations due to exploitation of aquifers.
The results of this study were obtained using SAR data from the sensor ASAR mounted on the satellite Envisat of the European Space Agency. Specifically, in this case, two SAR images acquired before (19/02/2011) and after the seismic event (03/21/2011) have been used.
Story Source:
The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Universitat Politècnica de Catalunya.
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
(Reuters) - Government engineers will blow up a third section of a Mississippi River levee on Thursday to manage flooding, as a wall of water roared down the nation's largest river system, threatening towns and cities all the way to the Gulf of Mexico. The U.S. Army Corps of Engineers blew up a two-mile section of the Birds Point levee Monday night, inundating about 130,000 acres of Missouri farmland in a desperate attempt to ease flooding in towns in Illinois and Kentucky.
Water levels did recede but a second, smaller section was detonated Tuesday afternoon to allow water back into the river. A third and last blast was scheduled for Wednesday but was delayed until 1 p.m. on Thursday by "logistical difficulties," the Corps said in a statement on Wednesday night.
The Corps, which is responsible for the system of locks and dams along the Mississippi River, would then turn its attention to the growing threat further south.
"The entire system is experiencing flooding and we will continue our fight downstream," said Major Gen. Michael J. Walsh, president of the Mississippi River Commission, in a statement.
President Barack Obama on Wednesday declared parts of Kentucky, Mississippi and Tennessee as disaster areas due to flooding, freeing up federal aid to help those affected.
Arkansas closed a 15-mile stretch of westbound lanes of one of the busiest road arteries in the nation, Interstate 40, for the time ever due to flooding, according to the state's transportation department. More than 31,000 vehicles travel daily through the section of road closed, and 65 to 70 percent of those are trucks, said Glenn Bolick, Arkansas Transportation
Department spokesman.
Highway officials were diverting traffic onto rural roads but even some of these were flooded, they said.
Further downstream in Mississippi, some residents of the historic Civil War town of Vicksburg were moving to higher ground on Wednesday to avoid the rising flood waters.
"We are not going to stay here," said Vicksburg resident Harold Manner. "The families all around us are taking what they can and moving out of here, at least for now."
The levee system in Mississippi is holding for now but it has never been tested like this before, officials said.
"Compared to the Great Mississippi Flood of 1927 this flood is going to be a lot nastier," said Marty Pope, senior hydrologist for the National Weather Service in Jackson.
Mississippi Governor Haley Barbour has had sandbags delivered to his Yazoo City home to prevent it from flooding.
Large amounts of rain and melt from the winter snow has caused a chain reaction of flooding from Canada and the Dakotas through Illinois, Indiana, Missouri, Kentucky, Arkansas and Tennessee. It is expected to soon hit Mississippi and Louisiana at the mouth of the Mississippi River.
The first waves to hit Hawaii from a tsunami triggered by a massive earthquake off Japan have washed up onshore at Waikiki, with no initial reports of any damage.
The Pacific Tsunami Warning Centre reported wave changes at Waianae Harbour around 3.24am on Friday (0024 AEDT Saturday), shortly before the relatively small waves were seen at Waikiki.
The Tsunami Warning Centre in Palmer, Alaska, placed Hawaii and parts of the US West Coast under a warning following Japan's magnitude 8.9 earthquake, urging residents to stay tuned for more information on rising waves.
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"It's not going to be a major damaging event," said Gerard Fryer with the Pacific Tsunami Warning Centre as the surge began to hit, although he added there might be scattered damage.
Waves were measured at 48cm at Nawiliwili on the island of Kauai, according to officials at an emergency centre in Honolulu.
The warnings also affected coastal areas through Central and South America as well as the western rim of the Pacific.
US President Barack Obama said he was monitoring the tsunami threat to his home state of Hawaii and the US West Coast after expressing condolences to those killed in the earthquake and offering to aid Japan.
"We are asking all our citizens in the affected region to listen to their state and local officials," he said in a statement.
"I have instructed FEMA (the Federal Emergency Management Agency) to be ready to assist Hawaii and the rest of the US states and territories that could be affected."
Hawaii is about 6500km east of the epicentre of Friday's earthquake.
Hawaii authorities were arranging buses to evacuate residents and opening evacuation centres.
"All residents in tsunami evacuation zones ... should evacuate immediately," the emergency department said.
Peter Carlisle, the mayor of the state capital Honolulu, told CNN authorities had ordered the evacuation based on the "worst-case scenario".
"One of the things about tsunamis is they're very, very unpredictable, and you can't tell how many waves there are going to be, which wave is going to be the one that is ... going to cause the greatest damage."
"It's a very, very difficult situation to confront."
The US Pacific Fleet command said, however, that it would not be evacuating any personnel or sailing ships out of Pearl Harbour, on the south-eastern side of Oahu island, near Honolulu.
"Projected wave assessments inside harbour indicate no need to sortie ships. Taking all measures to ensure ships secure in port," it said on the micro-blogging website Twitter.
The tsunami warning centre, based in Ewa Beach, west of Honolulu, issued a widespread warning extending across virtually the entire Pacific Ocean, including Antarctica and South America.
"A tsunami has been generated that could cause damage along coastlines of all islands in the state of Hawaii," the centre said.
"Urgent action should be taken to protect lives and property."
Waves heights cannot be predicted, and the first wave may not be the largest, it said.
People scrambled to stock up on fuel, and arguments broke out as lines formed in front of service stations, the Star Advertiser reported.
The warning issued by the Alaska monitoring station extended to Hawaii, the northern and central California coast, the Oregon coast, and parts of Alaska. It urged residents to move inland and to higher ground.
An advisory, a lesser state of alert, was issued for southern California and the Washington coast, where residents were urged to clear beaches and stay out of marinas and harbours.
"With an earthquake of this size, we could definitely see some water on the West Coast," said Cindi Preller, a watcher at the centre.
In Japan, Foreign Minister Takeiaki Matsumoto asked Tokyo asked US Ambassador John Roos for US forces stationed in the country for help in quake and tsunami relief efforts.
The United States, which occupied Japan after World War II and is now the country's main security ally, has almost 50,000 forces stationed in the country.
The most powerful earthquake to hit Japan in at least 100 years unleashed walls of water that swept across rice fields, engulfing towns, dragging houses onto highways and tossing cars and boats like toys. Local media reported at least 32 deaths, with more casualties feared. And the 8.9-magnitude quake, which struck at 2:46 p.m., prompted the U.S. National Weather Service to issue a tsunami warning for at least 20 countries.
The quake's epicenter was 373 kilometers (231 miles) away from Tokyo, the United States Geological Survey said.
But residents there continued to feel aftershocks hours after the quake. More than 30 aftershocks followed, with the strongest measuring at 7.1.
Japanese Prime Minister Naoto Kan appealed for calm and said there were no reported leaks of radioactive materials from power plants.
Four nuclear power plants closest to the quake were safely shut down, the UN nuclear watchdog agency said.
At Tokyo Station, one of Japan's busiest subway stations, shaken commuters grabbed one another to stay steady as the ground shook. Dazed residents poured into the streets after offices and schools were closed. Children cried.
The quake toppled cars off bridges and into waters underneath. Waves of debris flowed like lava across farmland, pushing boats, houses and trailers. About 4 million homes had no power in Tokyo and surrounding areas.
Firefighters battled a fiery blaze at an oil refinery in Chiba prefecture near Tokyo.
Residents said though earthquakes are common in Japan, Friday's stunned most people.
The biggest earthquake to hit Japan in 140 years struck the northeast coast on Friday, triggering a 10-meter tsunami that swept away everything in its path, including houses and cars.
At least six people were killed, five in Fukushima prefecture north of the capital, Tokyo, where four million homes were without power, and one in eastern Tochigi prefecture, media said. A hotel collapsed in the city of Sendai and people were feared buried in the rubble. Thirty international search and rescue teams stand ready to go to Japan to provide assistance following a major earthquake, the United Nations said on Friday.
"We stand ready to assist as usual in such cases," Elisabeth Byrs of the U.N. Office for the Coordination of Humanitarian Assistance (OCHA) told Reuters in Geneva. "Thirty international search and rescue teams are on alert and monitoring the situation and stand ready to assist if necessary."
The 8.9 magnitude quake caused many injuries, public broadcaster NHK said, sparked fires and the wall of water, prompting warnings to people to move to higher ground in coastal areas.
Digital News Report – Hundreds may still be trapped below the rubble in Christchurch New Zealand. The 6.3 magnitude earthquake hit the South Island of New Zealand at 12:51 pm local time Tuesday. The February 22nd earthquake may be remembered as one of the worst or the worst disaster in the nation’s history.
It is not certain whether this earthquake is an aftershock of the Sept 4 2010 quake that hit the Canterbury region of the island. Whether an aftershock or not, this quake caused more damage because it was shallower and closer to the metropolitan area of Christchurch.
New Zealand Prime Minster, John Key, says this may be “New Zealand’s darkest day”. He said that 65 are confirmed dead but others say the death-toll could reach two to four hundred.
The Mayor of Christchurch, Bob Parker, says 200 people could still be trapped. Residents are being asked to conserve water. The defense forces have been called to assist residents in the area.
Power has been disrupted and buildings and roads have been destroyed. Eye-witnesses said that buildings near Cathedral Square in downtown have collapsed. There is also a report that the Catholic Church has collapsed.
Workers are believed to be trapped in the Pyne Gould Corporation building on Cambridge Terrace.
The spire of the Christchurch Cathedral has completely collapsed. The hospital and airport were both been evacuated. The hospital has reopened to treat the injured.
The airport is opened for emergency traffic only. The United States has offered assistance and Australia is sending a rescue team to the scene.
Rescue efforts and aftershocks continue through the night amid reports that the toll could go much higher. Two buses are reported crushed as buildings in Christchurch topple.
The earthquake's epicenter was reportedly 3 miles below ground about 12 miles southeast of Christchurch, a gateway city to New Zealand's South Island. The Sept. 4 quake had a 7.1 magnitude but its epicenter was deeper and it struck much farther from Christchurch, officials said. There have been thousands of aftershocks in the area following the September quake.
Stuart said unconfirmed reports put the death toll at more than 90, with estimates that it could reach as many as 1,000.
"The people of Christchurch were just believing they may be over the worst when the quake struck today," said Stuart.
"There were screams from trapped people and others digging with their hands to free trapped people," Stuart said. "I talked by phone with one woman who pulled her bed mattress on top of her. There are lots of old stone buildings in Christchurch and lots of those collapsed."
THE Queen has said she is "delighted" following the birth of her first great-grandchild.
Buckingham Palace announced that the wife of the Queen's grandson Peter Phillips gave birth to a daughter yesterday.
Autumn and Peter Phillips' first child, whose name is yet to be confirmed, weighed 8lbs 8oz when she was born at Gloucestershire Royal Hospital.
A statement from Buckingham Palace read: "The Queen, the Duke of Edinburgh, the Princess Royal, Captain Mark Phillips and Autumn's family have been informed and are delighted with the news."
The baby is the first child for Mr and Mrs Phillips, the first grandchild for the Princess Royal and the first great-grandchild for the Queen and the Duke of Edinburgh. She is 12th in line to the throne.
Earthquakes are often followed by aftershocks, causing even more damage to already weakened buildings and roads.
Land, especially hills, can also be damaged by earthquakes and result in devastating landslides and mudslides.
What is an aftershock?
• It's basically a smaller earthquake that happens after the main quake, in the same area.
• If it registers higher on the Richter scale than the first quake, it's renamed as the main earthquake and the original main quake becomes known as a foreshock.
• Aftershocks can happen for up to two years after the original earthquake, losing power over time.
A memorial to the China earthquake, which happened on 12 May 2008
In recent years, there have been some really big earthquakes.
January 2010: A strong earthquake hit Haiti in the Caribbean. It devastated the country, and it's thought between 100,000 and 200,000 people died. Hundreds of buildings were demolished and 1.5 million people were made homeless.
Troops and aid are being sent in from all around the world to help the people there.
April 2009: Around 150 people are killed in central Italy when an earthquake struck in a city called L'Aquila. More than 50,000 people were left homeless by the quake.
May 2008: Around 87,000 people are thought to have been killed in China by an earthquake in the Sichuan region of the country. As many as five million homes were destroyed in the quake which measured 7.5 on the Richter scale, and was the biggest to strike the country for 30 years.
August 2007: More than 450 people are killed in Peru by a quake measuring 7.9 on the Richter scale.
May 2006: More than 3,000 people are killed by an earthquake that struck the Indonesian island of Java. More than 200,000 people were left without shelter quake, which measured 6.2 on the Richter scale.
December 2004: Some 300,000 people are killed when an earthquake in the Indian Ocean measuring 9.0 on the Richter scale sends huge waves called tsunamis crashing into several Asian countries. The worst countries affected were Indonesia, Sri Lanka, India and Thailand.
December 2003: Over 50,000 people are killed in a quake in Iran, which measured 6.3 on the Richter scale.
May 2003: Over 1,000 people are killed and nearly 7,000 hurt in a quake in Algeria, which measured 6.7 on the Richter scale.
March 2002: Thousands die in a remote area of Afghanistan after an earthquake measuring 6.0 on the Richter scale.
January 2001: 30,000 people die and more than 50,000 are injured by an earthquake measuring 7.9 on the Richter scale in Gujarat, India.
January 2001: 1,000 people die in a 7.2 earthquake in El Salvador.
Earthquakes can be very dangerous, if you are in the wrong place. They can make buildings fall down and set off landslides, as well as having many other deadly effects.
An earthquake which occurs on the seafloor can push water upwards and create massive waves called tsunamis.
These waves can reach speeds of up to 500 kilometres per hour and cause massive devastation to anything in their path.
Earthquakes are measured on the Richter Scale.
The higher the number on the scale, the more powerful the quake. The more powerful a quake is, the more damage it can cause.
Earthquakes have killed hundreds of thousands of people even though scientists are able to make buildings much safer than in the past.
Unfortunately many quakes happen in parts of the world where people can't afford to spend lots of money on safety measures.
A memorial to the China earthquake, which happened on 12 May 2008
