Sunday, April 21, 2013

PLANETARY TREMORS: Strong 6.1 Magnitude Earthquake Hits Japan's Izu Islands As Earthquake Swarm Continues Under Miyake Volcano!

April 21, 2013 - JAPAN - An earthquake measuring 6.1 on the Richter scale jolted Izu Islands, Japan at 03:22:16 GMT on Sunday, the U.S. Geological Survey said.

The epicenter, with a depth of 424.10 km, was initially determined to be at 29.9151 degrees north latitude and 138.9262 degrees east longitude.

Earthquake Swarm Continues Under Miyake Volcano At The Izu Islands.

A strong earthquake swarm, presumably caused by a magmatic intrusion, has started Wednesday at Miyake volcano in the Japanese Izu Islands. On Wednesday alone, JMA recorded 136 earthquakes with magnitudes up to an earthquake of magnitude 5.6, which was widely felt in the region. The quakes’ hypocenters are clustered in a NNW-SSW trending area about 10 km west of the island, at depths of 5-15 km. The volcano last erupted in 2010. - Volcano Discovery.

Tectonic Summary - Seismotectonics of the Philippine Sea and Vicinity.
The Philippine Sea plate is bordered by the larger Pacific and Eurasia plates and the smaller Sunda plate. The Philippine Sea plate is unusual in that its borders are nearly all zones of plate convergence. The Pacific plate is subducted into the mantle, south of Japan, beneath the Izu-Bonin and Mariana island arcs, which extend more than 3,000 km along the eastern margin of the Philippine Sea plate. This subduction zone is characterized by rapid plate convergence and high-level seismicity extending to depths of over 600 km. In spite of this extensive zone of plate convergence, the plate interface has been associated with few great (Magnitude greater than 8.0) ‘megathrust’ earthquakes. This low seismic energy release is thought to result from weak coupling along the plate interface (Scholz and Campos, 1995). These convergent plate margins are also associated with unusual zones of back-arc extension (along with resulting seismic activity) that decouple the volcanic island arcs from the remainder of the Philippine Sea Plate (Karig et al., 1978; Klaus et al., 1992).

South of the Mariana arc, the Pacific plate is subducted beneath the Yap Islands along the Yap trench. The long zone of Pacific plate subduction at the eastern margin of the Philippine Sea Plate is responsible for the generation of the deep Izu-Bonin, Mariana, and Yap trenches as well as parallel chains of islands and volcanoes, typical of circum-pacific island arcs. Similarly, the northwestern margin of the Philippine Sea plate is subducting beneath the Eurasia plate along a convergent zone, extending from southern Honshu to the northeastern coast of Taiwan, manifested by the Ryukyu Islands and the Nansei-Shoto (Ryukyu) trench. The Ryukyu Subduction Zone is associated with a similar zone of back-arc extension, the Okinawa Trough. At Taiwan, the plate boundary is characterized by a zone of arc-continent collision, whereby the northern end of the Luzon island arc is colliding with the buoyant crust of the Eurasia continental margin offshore China.

USGS historic seismicity for the region.

Along its western margin, the Philippine Sea plate is associated with a zone of oblique convergence with the Sunda Plate. This highly active convergent plate boundary extends along both sides the Philippine Islands, from Luzon in the north to the Celebes Islands in the south. The tectonic setting of the Philippines is unusual in several respects: it is characterized by opposite-facing subduction systems on its east and west sides; the archipelago is cut by a major transform fault, the Philippine Fault; and the arc complex itself is marked by active volcanism, faulting, and high seismic activity. Subduction of the Philippine Sea Plate occurs at the eastern margin of the archipelago along the Philippine Trench and its northern extension, the East Luzon Trough. The East Luzon Trough is thought to be an unusual example of a subduction zone in the process of formation, as the Philippine Trench system gradually extends northward (Hamburger et al., 1983). On the west side of Luzon, the Sunda Plate subducts eastward along a series of trenches, including the Manila Trench in the north, the smaller less well-developed Negros Trench in the central Philippines, and the Sulu and Cotabato trenches in the south (Cardwell et al., 1980). At its northern and southern terminations, subduction at the Manila Trench is interrupted by arc-continent collision, between the northern Philippine arc and the Eurasian continental margin at Taiwan and between the Sulu-Borneo Block and Luzon at the island of Mindoro. The Philippine fault, which extends over 1,200 km within the Philippine arc, is seismically active. The fault has been associated with major historical earthquakes, including the destructive M7.6 Luzon earthquake of 1990 (Yoshida and Abe, 1992). A number of other active intra-arc fault systems are associated with high seismic activity, including the Cotabato Fault and the Verde Passage-Sibuyan Sea Fault (Galgana et al., 2007).

Relative plate motion vectors near the Philippines (about 80 mm/yr) is oblique to the plate boundary along the two plate margins of central Luzon, where it is partitioned into orthogonal plate convergence along the trenches and nearly pure translational motion along the Philippine Fault (Barrier et al., 1991). Profiles B and C reveal evidence of opposing inclined seismic zones at intermediate depths (roughly 70-300 km) and complex tectonics at the surface along the Philippine Fault.

Several relevant tectonic elements, plate boundaries and active volcanoes, provide a context for the seismicity presented on the main map. The plate boundaries are most accurate along the axis of the trenches and more diffuse or speculative in the South China Sea and Lesser Sunda Islands. The active volcanic arcs (Siebert and Simkin, 2002) follow the Izu, Volcano, Mariana, and Ryukyu island chains and the main Philippine islands parallel to the Manila, Negros, Cotabato, and Philippine trenches.

Seismic activity along the boundaries of the Philippine Sea Plate (Allen et al., 2009) has produced 7 great (Magnitude greater than 8.0) earthquakes and 250 large (Magnitude greater than 7) events. Among the most destructive events were the 1923 Kanto, the 1948 Fukui and the 1995 Kobe (Japan) earthquakes (99,000, 5,100, and 6,400 casualties, respectively), the 1935 and the 1999 Chi-Chi (Taiwan) earthquakes (3,300 and 2,500 casualties, respectively), and the 1976 M7.6 Moro Gulf and 1990 M7.6 Luzon (Philippines) earthquakes (7,100 and 2,400 casualties, respectively). There have also been a number of tsunami-generating events in the region, including the Moro Gulf earthquake, whose tsunami resulted in more than 5000 deaths. - USGS.

MASS ANIMAL/BIRD/FISH DIE-OFF IN THE UK: Hundreds Of Dead Fish Found In River Stour In Kent, England; Over 1,000 Birds Washed Up Dead From Oil Pollution In Cornwall And Devon, England; Over 20,000 Sheep Dead From Snowfall In Northern Ireland, Many More Still Buried In Snow; Pile Of Dead Frogs Found At Singelton Lakes In Ashford, Kent, England; Worry Over Marsh Horses "Dropping Dead Like Flies" In Wales!

April 21, 2013 - UNITED KINGDOM -The number of birds that have died after being washed up on South West beaches has passed 1,000.  The shocking total, described by wildlife charities as “a whole generation of seabirds”, comes just a week after the first reports of seabirds covered in a sticky glue-like substance being found across the Westcountry coastline. 

Over 1,000 Birds Washed Up Dead From Oil Pollution In Devon And Cornwall, England.

This is in addition to more than 200 birds currently in the care of the RSPCA and South Devon Seabird Trust. It is the second time in just three months that the substance identified by Plymouth University researchers as polyisobutene – or PIB - has killed hundreds of seabirds in the South West.  “This is an absolute tragedy for wildlife, but it is bad for all of us too,” said Harry Barton, chief executive of Devon Wildlife Trust. “Our region is famous for its stunning natural environment and clean beaches, and that is why we have such a successful tourist industry.  "The prospect of wading through piles of dead birds on the shore is hardly the advertisement we want. This is the clearest possible sign that our economy depends on a healthy natural environment.  “Pollution incidents like this can be prevented if the political will is there to do so,” said Mr Barton. “We must act quickly and decisively to stop this happening a third time.”  In this latest incident birds have been found in a wide area from Dodman Point, Cornwall, to the Teign Estuary, Devon, but the worst hit areas have been beaches along Whitsand Bay in South East Cornwall where locals have been counting hundreds of birds every day.  Alison Fogg, zoologist and environment campaigner who lives by the sea near Lanteglos, Cornwall, has been close to the unfolding disaster: “It is hard to sum up so many different emotions, from the last few days, in a few words.  “Seeing over 157 dead birds on Lansallos beach, followed by hundreds more at Lantic Bay, was quite devastating. Lansallos is a small sheltered beach on the South Coast of Cornwall,” she said. 

“The scale of destruction to wildlife, in the beginning of the bird breeding season and at the start of the tourist season is quite difficult to comprehend.”  It is not known whether the substance got into the sea as a spill from a ship or as part of legal and routine tank washing operations, said Tony Whitehead, from the RSPB.  “The devastation this substance has caused has been appalling,” Mr Whitehead said. “To see the images of beaches strewn with bodies is a sobering reminder that we just cannot go on treating our precious marine environment as a dustbin.  “If this was an illegal spill, we need to support the Maritime and Coastguard Agency in tracking down the ship responsible. Although this will be difficult, surely it’s not impossible.  “If this was the result of legal tank washing operations, we need to urge the International Maritime Organisation to tighten up the rules and make it illegal to wash this stuff into the sea. It’s a noxious substance and we don’t want it in our marine environment.”  Abby Crosby, marine conservation officer for Cornwall Wildlife Trust, said people have been responding to an appeal to contact it about birds in distress.  “The public have been calling our hotline in droves,” she said, “and our brilliant strandings volunteers have been sending in their reports. But, as dead birds may continue to wash up, we need to keep on recording.  “It has been a terribly sad time for everyone seeing these beautiful birds washing up dead in horrific numbers along our coastline. Something must change in the legislation managing our seas to stop this happening again.” - Plymouth Herald.

Hundreds Of Dead Fish Found In River Stour In Kent, England.
Pollution is believed to have killed hundreds of fish spotted floating along the River Stour in Ashford.  The Environment Agency is now investigating the cause for the deaths but said that initial findings suggest the problem has been contained to the Ashford area.  Ruth Moore, 66, of Tufton Road, Ashford, and her daughter Hannah Moore, 38, reported the dead fish to the Environment Agency yesterday afternoon after they saw them on their walk home near the Stour Centre.  Mrs Moore said: “It was a sad and horrible sight. We are an animal loving family and the worst part was seeing the big pike dying and struggling for air.”

Lewis Brown from the Environment Agency said: “The Environment Agency was made aware of a pollution incident on the River Stour in Ashford yesterday afternoon.  “Our officers attended the scene and have been working with Kent County Council and Ashford Borough Council to investigate. We are monitoring the situation.  “Our initial investigation suggests that the impact has been localised, this morning we have not seen any fresh signs of pollution or fish in distress."  The Environment Agency is appealing to anyone with information about the pollution to call their hotline.  Mr Brown added: “If anyone has seen anyone acting suspiciously or has concern or information about pollution to the river please call our emergency hotline 0800 807060.” - Kent Online.

Pile Of Dead Frogs Found At Singelton Lakes In Ashford, Kent, England.
One of the dead frogs discovered by wildlife enthusiast Matt Lacey at Singleton Lakes.
A wildlife enthusiast was shocked to discover a pile of up to 50 dead frogs near an Ashford lake.  Matt Lacey is now calling for action, claiming waste dumped at Singleton Lakes might have poisoned the large number of animals.  The 30-year-old, from Singleton, said he has discovered the bodies of scoresWildlife enthusiast Matt Lacey of the creatures when walking at the lakes. Mr Lacey - who owns several reptiles, including snakes, lizards and geckos - attempted to isolate waste dumped in the area by damming off a smaller pool from the main lakes.  He said: "I took my son down to show him the wildlife, and I noticed piles of dead frogs.  "I started searching the bushes and the more I looked, the more I found. There must have been around 40 to 50 bodies in total.  "I made a dam to separate a stagnant pool, where I found drums of chip fat, brake fluid and other rubbish, from the main pond. 

The dead frogs were discovered at Singleton Lakes, near Ashford.

"My worry is, if the water level rises, the whole area could be affected. And if the substance is poisonous and a dog picks up a carcass, it could lead to some expensive vets bills for their owners.  "Perhaps we could organise a few volunteers to help the clear up the area and prevent this from happening again."  Mr Lacey also called the police and Environment Agency, who attended the scene after he made the discovery. An Environment Agency spokesman said: "An officer went out to the site last Thursday and Friday and reported one dead frog.  "We went out to the site again on Tuesday and have seen five dead frogs. There are no dead fish or birds and the frogs were discovered in a ditch which currently has no water flowing through it.  "The officer tested for dissolved oxygen and ammonia and all results have come back clear and the oxygen levels are fine." - Kent Online.

Over 20,000 Sheep Dead From Snowfall In Northern Ireland, Many More Still Buried In Snow.
The number of dead sheep cleared from farms hit by the recent snow blizzards has now topped 20,000 — and many more are still to come. Department of Agriculture officials last night said 20,000 animals had been collected from farms across Co Down and the Glens of Antrim.  Of those 15,000 were lambs and 5,000 ewes.  Meanwhile 623 dead cattle have also been collected, of which 223 were calves under the age of three months, the officials told Stormont’s Agriculture Committee.  Dead animals have now been collected from 790 farms and renderers have received 1,450 calls from farmers seeking to have animals cleared under a state-funded disposal scheme set in motion by Agriculture Minister Michelle O’Neill.  Officials said 289 farmers have now been approved for aid under the scheme, while 23 were found to be ineligible and 11 are still being dealt with. 

However, sheep farmers have warned that animal carcasses are still scattered across the uplands hit by the worst of the blizzards and many of these will still not have been retrieved by the time the scheme comes to a close on April 19.  Members of the National Sheep Association have called for the carcass collection to be extended beyond that date.  John Blaney of the National Sheep Association said farmers are in the middle of lambing at the moment and don’t have time to spare to scour the hills for carcasses.  Meanwhile, there are still deep drifts of snow in some remote areas where animals are still buried.  “Probably it will be into May before we can get the full extent. It’s very difficult to get the full picture,” he said.  DARD officials said 70 of the sheep farmed by Greenmount College at Glenwherry were found but 70 are still missing.  Deputy chief veterinary officer Robert Huey said he would be advising the minister that the postcode application scheme for dealing with carcasses end on April 19 but the scheme be kept open for exceptional cases.  Many of the animals still missing are likely to have made for the shelter of walls where it is likely their remains could be found in groups in various stages of decomposition, he said. - Belfast Telegraph.

Worry Over Marsh Horses "Dropping Dead Like Flies" In Wales.
Horses have been "dropping like flies" on the Loughor Estuary, according to a lifeboatman.  John Edwards said horses have congregated at the marsh near Loughor inshore lifeboat station for years, and knew how to steer clear of the incoming tide, but that a high number of the animals had got stuck in the mud or perished.  The Post has been emailed photographs which are too shocking to print of horse carcasses on the marsh. The photographer, who asked the Post not to name her, also sent this snap (left) of what she says are horse bones at the same location.  The RSPCA is investigating. Swansea Council said the dead animals were on the Carmarthenshire side of the estuary, while Carmarthenshire Council said the area was "a bit of a no-man's land".  Loughor inshore lifeboat station secretary Mr Edwards said: "I don't know what is going on. We have never had these problems before. All of a sudden they are dropping like flies."

Grim sight bones found near the Loughor Estuary.

Mr Edwards said the lifeboat had launched to help mud-trapped horses, but had to be careful not to scare the animals and make the situation worse.  "Unless they are actually in danger we won't respond," he said.  "People say it's the owners' responsibility, but a lot of them are wild horses. Our concern is that if the animals are left to rot they (their remains) will go back into the water."  Mr Edwards said there were around 40 horses opposite the lifeboat station, and that an elderly man often used to pop along with bread for them. "When the tide comes in they go onto the bank and huddle together," he said.  The anonymous photographer described seeing 24 dead horses - or remains of. "For any person that feels these horses are at home on these marshes and estuary, may they think again," she said.  The Welsh Government is holding a consultation on fly-grazing and horse abandonment which ends on April 29.  The RSPCA meanwhile said it had removed three live horses this week from the Gower marshes which are now in the charity's care.  An RSPCA spokesman added: "Police and Natural Resources Wales have removed all the animal carcasses that were on the site. An RSPCA investigation is ongoing." - South Wales Evening Post.

GEOLOGICAL UPHEAVAL: Tracking Developments At The Giant Louisiana Sinkhole - After "Burp" Event, Trees Sinking Straight Into The Ground As Liquid Shifts Back And Forth!

April 21, 2013 - UNITED STATES - Here is the latest update from the Assumption Parish Police Jury on the giant Louisiana sinkhole:

A video was captured yesterday after the “burp” in the sinkhole.

You can clearly see trees sinking and immediately thereafter, the movement of the water in the sinkhole.

Watch the video HERE.

PLANETARY TREMORS: 6.1 Magnitude Earthquake Strikes Off Kuril Islands!

April 21, 2013 - KURIL ISLANDS - An earthquake measuring 6.1 on the Richter scale jolted Kuril Islands at 13:12:51 GMT on Saturday, the U.S. Geological Survey said.

The epicenter, with a depth of 20.20 km, was initially determined to be at 50.1398 degrees north latitude and 157.2247 degrees east longitude.

Tectonic Summary - Seismotectonics of the Kuril-Kamchatka Arc
The April 19, 2013 M 7.2 earthquake ENE of Kuril’sk, Russia, occurred as a result of oblique normal faulting at intermediate depths within the subducting lithosphere of the Pacific plate. At the latitude of this earthquake, the Pacific plate converges with the North America plate (and the smaller Okhotsk microplate) towards the west-northwest at a velocity of approximately 82 mm/yr, and subducts beneath the Kuril Islands at the Kuril-Kamchatka trench, some 160 km to the southeast of the April 19 event. The depth of this earthquake, and its oblique-faulting mechanism, indicate that it involved intraplate faulting within the subducting slab, rather than being an interplate thrust event on the shallower seismogenic zone between the two tectonic plates.

The Kuril-Kamchatka arc has frequent moderate-to-large earthquakes, and has hosted over three-dozen M 6.5+ events within 250 km of the April 19 earthquake over the past 40 years. None are known to have caused shaking-related fatalities. The largest of these was the November 2006 M 8.3 interplate thrust event, approximately 200 km to the east of the April 19 earthquake. However, while the Pacific slab is seismically active in this region to depths of almost 700 km, just one of these nearby M 6.5+ events has occurred at depths greater than 70 km – a M 6.7 event in October 1994, 130 km to the southwest.

Intermediate depth (70 – 300km) and deep-focus (depth greater than 300 km) earthquakes are distinguished from shallow earthquakes (depth less than 70 km) by the nature of their tectonic setting, and are in general much less hazardous than their shallow counterparts, though they may be felt at great distances from their epicenters.

USGS historic seismicity for the region.

The Kuril-Kamchatka arc extends approximately 2,100 km from Hokkaido, Japan, along the Kuril Islands and the Pacific coast of the Kamchatka Peninsula to its intersection with the Aleutian arc near the Commander Islands, Russia. It marks the region where the Pacific plate subducts into the mantle beneath the Okhotsk microplate, part of the larger North America plate. This subduction is responsible for the generation of the Kuril Islands chain, active volcanoes located along the entire arc, and the deep offshore Kuril-Kamchatka trench. Relative to a fixed North America plate, the Pacific plate is moving towards the northwest at a rate that increases from 75 mm/year near the northern end of the arc to 83 mm/year in the south.

Plate motion is predominantly convergent along the Kuril-Kamchatka arc with obliquity increasing towards the southern section of the arc. The subducting Pacific plate is relatively old, particularly adjacent to Kamchatka where its age is greater than 100 Ma. Consequently, the Wadati-Benioff zone is well defined to depths of approximately 650 km. The central section of the arc is comprised of an oceanic island arc system, which differs from the continental arc systems of the northern and southern sections. Oblique convergence in the southern Kuril arc results in the partitioning of stresses into both trench-normal thrust earthquakes and trench-parallel strike-slip earthquakes, and the westward translation of the Kuril forearc. This westward migration of the Kuril forearc currently results in collision between the Kuril arc in the north and the Japan arc in the south, resulting in the deformation and uplift of the Hidaka Mountains in central Hokkaido.

The Kuril-Kamchatka arc is considered one of the most seismically active regions in the world. Deformation of the overriding North America plate generates shallow crustal earthquakes, whereas slip at the subduction zone interface between the Pacific and North America plates generates interplate earthquakes that extend from near the base of the trench to depths of 40 to 60 km. At greater depths, Kuril-Kamchatka arc earthquakes occur within the subducting Pacific plate and can reach depths of approximately 650 km.

This region has frequently experienced large (Magnitude greater than 7) earthquakes over the past century. Since 1900, seven great earthquakes (M8.3 or larger) have also occurred along the arc, with mechanisms that include interplate thrust faulting, and intraplate faulting. Damaging tsunamis followed several of the large interplate megathrust earthquakes. These events include the February 3, 1923 M8.4 Kamchatka, the November 6,1958 M8.4 Etorofu, and the September 25, 2003 M8.3 Hokkaido earthquakes. A large M8.5 megathrust earthquake occurred on October 13, 1963 off the coast of Urup, an island along the southern Kuril arc, which generated a large tsunami in the Pacific Ocean and the Sea of Okhotsk, and caused run-up wave heights of up to 4-5 m along the Kuril arc. The largest megathrust earthquake to occur along the entire Kurile-Kamchatka arc in the 20th century was the November 4, 1952 M9.0 event. This earthquake was followed by a devastating tsunami with run-up wave heights as high as 12 m along the coast of Paramushir, a small island immediately south of Kamchatka, causing significant damage to the city of Severo-Kurilsk.

On October 4,1994, a large (M8.3) intraplate event occurred within the subducted oceanic lithosphere off the coast of Shikotan Island causing intense ground shaking, landslides, and a tsunami with run-up heights of up to 10 m on the island.

The most recent megathrust earthquake in the region was the November 15, 2006 M8.3 Kuril Island event, located in the central section of the arc. Prior to this rupture, this part of the subduction zone had been recognized as a seismic gap spanning from the northeastern end of the 1963 rupture zone to the southwestern end of the 1952 rupture. Two months after the 2006 event, a great (M8.1) normal faulting earthquake occurred on January 13, 2007 in the adjacent outer rise region of the Pacific plate. It has been suggested that the 2007 event may have been caused by the stresses generated from the 2006 earthquake. - USGS.

PLAGUES & PESTILENCES: Costa Rica Reports Fowl Typhoid Outbreak - 64,481 Birds Affected; Of Which 1,566 Died!

April 21, 2013 - COSTA RICA - There has been an outbreak of fowl typhoid at an egg farm in central Costa Rica.

Map of outbreak locations.
Image: OIE.

The veterinary authority sent an Immediate Notification dated 15 April to the World Organisation for Animal Health (OIE).

The report describes one outbreak of fowl cholera, caused by Salmonella gallinarum, at a commercial layer farm with eggs for human consumption in San Miguel in the state of Alajuela in central Costa Rica.

Image: OIE.

Image: OIE.

Starting on 23 March, the outbreak affected 64,481 birds, of which 1,566 died.

Investigations are on-going in neighbouring holdings in order to find new outbreaks. Biosecurity measures are strengthened, including control of infestations such as rodents and flies in the affected farm, which is under quarantine. Samples will be sent to an international laboratory to carry out genome sequencing of isolated bacteria.

Image: OIE.

The following measures have been applied: quarantine, movement control inside the country, disinfection of infected premises/establishment(s), vaccination is prohibited and there is no treatment of affected animals.

The last outbreak of fowl typhoid in Costa Rica was in 1999. - The Poultry Site.

PLANETARY TREMORS & GEOLOGICAL UPHEAVAL: Most Powerful 6.6 Magnitude Earthquake Strikes China's Sichuan Province Destroying Hundreds Of Homes And Creating Many Landslides - 1,100 Aftershocks; Almost 200 Killed; Over 11,000 Injured; Thousands Displaced!

"It was as if the mountain was alive ... Now I have no home to go". - Sichuan earthquake survivor.

April 21, 2013 - CHINA
- Thousands of rescuers are fighting to thwart a rising death toll as they search earthquake-shattered villages in southwest China for survivors.

Homes were razed and lives destroyed in the deadliest earthquake to hit China in three years.

Rescue teams battled landslides and collapsed roads to reach isolated parts of Sichuan province on the edge of the Tibetan Plateau, in images aired on state broadcaster CCTV on Sunday.  Almost 200 people have so far been confirmed dead, with more than 11,000 injured in Saturday's 6.6 magnitude quake. Almost 1,000 were seriously injured in the quake.  Soldiers searched through the night and day for survivors in villages where houses had been destroyed and treated some of the injured.  China's new Premier Li Keqiang has rushed to the disaster zone and was shown by CCTV eating breakfast in a tent.

USGS earthquake map and location.

"The rescue effort is our first duty," he told state media.  Xinhua news agency said more than 17,000 Chinese soldiers, pilots and police had joined the rescue mission and five drones were sent to capture aerial images.  A military vehicle carrying 17 troops headed for the quake area plummeted over a cliff on Saturday, killing one soldier and injuring seven others. 

WATCH: Deadly quake strikes China's Sichuan province.

Al Jazeera’s Robert McBride, reporting from Hong Kong, said the suddenness of the earthquake had contrasted with the 2008 one in the same province, which left more than 90,000 people dead or missing.  "People are now watching to see how the new leadership is dealing with this," McBride said.  "This their first test of how they deal this natural disaster."

The 6.6 magnitude earthquake has devastated the lives of villagers in southwest China,
destroying houses an cutting power.

Hospitals have been inundated with thousands of injured people and have been forced to erect
makeshift tents to treat the wounded.

People have lost their homes and their livelihoods, with many farmers losing livestock.

The rescue operation was hampered by huge queues of traffic, some stretching back for 20km, that clogged roads into the disaster zone. "We really want to go in and help people, but instead we are waiting in traffic," one relief official said in his car.   Boulders the size of cars littered streets in Lushan county, the epicentre of the earthquake.  More than 1,100 aftershocks have followed since the quake struck Sichuan province on Saturday morning.  Chinese seismologists registered the tremor at 7.0 magnitude while the US Geological Survey gave it as 6.6.  Firefighters helped by sniffer dogs pulled 91 people alive from the rubble, Xinhua said, citing the Ministry of Public Security.  A steady stream of ambulances continued to arrive at Lushan People's Hospital on Sunday.  Most survivors were taken to tents erected in the grounds surrounding the hospital, where doctors treated the wounded.

China dispatched more than 17,000 rescuers, including the military, to search for and rescue survivors.

Rescuers battled landslides and aftershocks to reach the remote region.

More than 90 people have been pulled alive from rubble as more than 17,000 rescuers help out.

Devastation left people vying for basic needs, such as food, water and blankets, as quake razed homes.

Power cut
A 68-year-old woman with a broken arm spoke of the terror she experienced when the earthquake struck. "It was as if the mountain was alive," she told the AFP news agency. "Now I have no home to go, so I don't know what I am going to do."  The earthquake cut off power and water supplies to much of the area, with Longquan villager Sot Yang Yiyun among the many affected.  "Now we don't have drinking water and power," Sot said.  "We must wait for the government to come and help us out. Also we want to call for help from other parts of the country."  Earthquake-prone Japan, which has been mired in tension with China over a high-seas territorial dispute , offered any help that was required.  "Japan is ready to offer its maximum support," Prime Minister Shinzo Abe said in a message to Chinese President Xi Jinping and Premier Li, according to Japan's foreign ministry.  China responded that overseas help was not needed but it would contact Tokyo if the situation changed, the ministry said. - Aljazeera.

WATCH:  China in rescue effort after deadly quake.

Tectonic Summary
The April 20, 2013 UTC Mw6.6 earthquake in the Sichuan province of China occurred as the result of east-west oriented reverse-type motion on a north-south striking fault. A preliminary source location suggest the event likely occurred on the Longmenshan fault or a tectonically related fault at a depth of 12km. The Longmenshan fault was the source fault of the May 12, 2008 Mw7.9 Sichuan earthquake. The preliminary April 20 event location is approximately 85km from the hypocentral location of the 2008 Sichuan earthquake. The April 20 earthquake reflects tectonic stresses resulting from the convergence of crustal material slowly moving from the high Tibetan Plateau, to the west, against strong crust underlying the Sichuan Basin and southeastern China.

On a continental scale, the seismicity of central and eastern Asia is a result of northward convergence of the India plate against the Eurasia plate with a velocity of about 50 mm/y. The convergence of the two plates is broadly accommodated by the uplift of the Asian highlands and by the motion of crustal material to the east away from the uplifted Tibetan Plateau.

Four events of Mw6.0 or greater have occurred within 200km of the April 19 event in the past 40 years, including the May 2008 Sichuan earthquake and a subsequent aftershock. The northwestern margin of the Sichuan Basin has previously experienced destructive earthquakes. The magnitude 7.5 earthquake of August 25, 1933, killed more than 9,300 people, while the May 12, 2008 killed 69,197.

Seismotectonics of the Himalaya and Vicinity
Seismicity in the Himalaya dominantly results from the continental collision of the India and Eurasia plates, which are converging at a relative rate of 40-50 mm/yr. Northward underthrusting of India beneath Eurasia generates numerous earthquakes and consequently makes this area one of the most seismically hazardous regions on Earth. The surface expression of the plate boundary is marked by the foothills of the north-south trending Sulaiman Range in the west, the Indo-Burmese Arc in the east and the east-west trending Himalaya Front in the north of India.

The India-Eurasia plate boundary is a diffuse boundary, which in the region near the north of India, lies within the limits of the Indus-Tsangpo (also called the Yarlung-Zangbo) Suture to the north and the Main Frontal Thrust to the south. The Indus-Tsangpo Suture Zone is located roughly 200 km north of the Himalaya Front and is defined by an exposed ophiolite chain along its southern margin. The narrow (less than 200km) Himalaya Front includes numerous east-west trending, parallel structures. This region has the highest rates of seismicity and largest earthquakes in the Himalaya region, caused mainly by movement on thrust faults. Examples of significant earthquakes, in this densely populated region, caused by reverse slip movement include the 1934 M8.1 Bihar, the 1905 M7.5 Kangra and the 2005 M7.6 Kashmir earthquakes. The latter two resulted in the highest death tolls for Himalaya earthquakes seen to date, together killing over 100,000 people and leaving millions homeless. The largest instrumentally recorded Himalaya earthquake occurred on 15th August 1950 in Assam, eastern India. This M8.6 right-lateral, strike-slip, earthquake was widely felt over a broad area of central Asia, causing extensive damage to villages in the epicentral region.

USGS historic seismicity for the region.

The Tibetan Plateau is situated north of the Himalaya, stretching approximately 1000km north-south and 2500km east-west, and is geologically and tectonically complex with several sutures which are hundreds of kilometer-long and generally trend east-west. The Tibetan Plateau is cut by a number of large (greater than 1000km) east-west trending, left-lateral, strike-slip faults, including the long Kunlun, Haiyuan, and the Altyn Tagh. Right-lateral, strike-slip faults (comparable in size to the left-lateral faults), in this region include the Karakorum, Red River, and Sagaing. Secondary north-south trending normal faults also cut the Tibetan Plateau. Thrust faults are found towards the north and south of the Tibetan Plateau. Collectively, these faults accommodate crustal shortening associated with the ongoing collision of the India and Eurasia plates, with thrust faults accommodating north south compression, and normal and strike-slip accommodating east-west extension.

Along the western margin of the Tibetan Plateau, in the vicinity of south-eastern Afghanistan and western Pakistan, the India plate translates obliquely relative to the Eurasia plate, resulting in a complex fold-and-thrust belt known as the Sulaiman Range. Faulting in this region includes strike-slip, reverse-slip and oblique-slip motion and often results in shallow, destructive earthquakes. The active, left-lateral, strike-slip Chaman fault is the fastest moving fault in the region. In 1505, a segment of the Chaman fault near Kabul, Afghanistan, ruptured causing widespread destruction. In the same region the more recent 30 May 1935, M7.6 Quetta earthquake, which occurred in the Sulaiman Range in Pakistan, killed between 30,000 and 60,000 people.

On the north-western side of the Tibetan Plateau, beneath the Pamir-Hindu Kush Mountains of northern Afghanistan, earthquakes occur at depths as great as 200 km as a result of remnant lithospheric subduction. The curved arc of deep earthquakes found in the Hindu Kush Pamir region indicates the presence of a lithospheric body at depth, thought to be remnants of a subducting slab. Cross-sections through the Hindu Kush region suggest a near vertical northerly-dipping subducting slab, whereas cross-sections through the nearby Pamir region to the east indicate a much shallower dipping, southerly subducting slab. Some models suggest the presence of two subduction zones; with the Indian plate being subducted beneath the Hindu Kush region and the Eurasian plate being subducted beneath the Pamir region. However, other models suggest that just one of the two plates is being subducted and that the slab has become contorted and overturned in places.

Shallow crustal earthquakes also occur in this region near the Main Pamir Thrust and other active Quaternary faults. The Main Pamir Thrust, north of the Pamir Mountains, is an active shortening structure. The northern portion of the Main Pamir Thrust produces many shallow earthquakes, whereas its western and eastern borders display a combination of thrust and strike-slip mechanisms. On the 18 February 1911, the M7.4 Sarez earthquake ruptured in the Central Pamir Mountains, killing numerous people and triggering a landside, which blocked the Murghab River.

Further north, the Tian Shan is a seismically active intra-continental mountain belt, which extends 2500 km in an ENE-WNW orientation north of the Tarim Basin. This belt is defined by numerous east-west trending thrust faults, creating a compressional basin and range landscape. It is generally thought that regional stresses associated with the collision of the India and Eurasia plates are responsible for faulting in the region. The region has had three major earthquakes (greater than M7.6) at the start of the 20th Century, including the 1902 Atushi earthquake, which killed an estimated 5,000 people. The range is cut through in the west by the 700-km-long, northwest-southeast striking, Talas-Ferghana active right-lateral, strike-slip fault system. Though the system has produced no major earthquakes in the last 250 years, paleo-seismic studies indicate that it has the potential to produce M7.0+ earthquakes and it is thought to represent a significant hazard.

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The northern portion of the Tibetan Plateau itself is largely dominated by the motion on three large left-lateral, strike-slip fault systems; the Altyn Tagh, Kunlun and Haiyuan. The Altyn Tagh fault is the longest of these strike slip faults and it is thought to accommodate a significant portion of plate convergence. However, this system has not experienced significant historical earthquakes, though paleoseismic studies show evidence of prehistoric M7.0-8.0 events. Thrust faults link with the Altyn Tagh at its eastern and western termini. The Kunlun Fault, south of the Altyn Tagh, is seismically active, producing large earthquakes such as the 8th November 1997, M7.6 Manyi earthquake and the 14th November 2001, M7.8 Kokoxili earthquake. The Haiyuan Fault, in the far north-east, generated the 16 December 1920, M7.8 earthquake that killed approximately 200,000 people and the 22 May 1927 M7.6 earthquake that killed 40,912.

The Longmen Shan thrust belt, along the eastern margin of the Tibetan Plateau, is an important structural feature and forms a transitional zone between the complexly deformed Songpan-Garze Fold Belt and the relatively undeformed Sichuan Basin. On 12 May 2008, the thrust belt produced the reverse slip, M7.9 Wenchuan earthquake, killing over 87,000 people and causing billions of US dollars in damages and landslides which dammed several rivers and lakes.

Southeast of the Tibetan Plateau are the right-lateral, strike-slip Red River and the left-lateral, strike-slip Xiangshuihe-Xiaojiang fault systems. The Red River Fault experienced large scale, left-lateral ductile shear during the Tertiary period before changing to its present day right-lateral slip rate of approximately 5 mm/yr. This fault has produced several earthquakes greater than M6.0 including the 4 January 1970, M7.5 earthquake in Tonghai which killed over 10,000 people. Since the start of the 20th century, the Xiangshuihe-Xiaojiang Fault system has generated several M7.0+ earthquakes including the M7.5 Luhuo earthquake which ruptured on the 22 April 1973. Some studies suggest that due to the high slip rate on this fault, future large earthquakes are highly possible along the 65km stretch between Daofu and Qianning and the 135km stretch that runs through Kangding.

Shallow earthquakes within the Indo-Burmese Arc, predominantly occur on a combination of strike-slip and reverse faults, including the Sagaing, Kabaw and Dauki faults. Between 1930 and 1956, six M7.0+ earthquakes occurred near the right-lateral Sagaing Fault, resulting in severe damage in Myanmar including the generation of landslides, liquefaction and the loss of 610 lives. Deep earthquakes (200km) have also been known to occur in this region, these are thought to be due to the subduction of the eastwards dipping, India plate, though whether subduction is currently active is debated. Within the pre-instrumental period, the large Shillong earthquake occurred on the 12 June 1897, causing widespread destruction. - USGS.