Updated 3/27/2011
Northern Burma was hit by a 7.0M earthquake Thursday, March 24, 2011 at 13:55 UTC (8:25 pm local time). 74 people were reported killed and 111 injured. 413 buildings were damaged and one bridge destroyed. The epicenter was 365 miles NE of Rangoon in the remote northern part of the country near the border of Laos, Thailand and China. The quake was felt as far away as Hanoi and Bangkok.
This quake follows a 5.4M quake just across the border in southern Yunaan Province in China that caused extensive damage. Initial reports were that 24 people were killed, 207 injured and over 1,000 buildings damaged in that quake.
The quake was caused by the movement of the Indian Plate NNE into the Eurasian Plate at the rate of 45mm(1.77 inches)/yr. This is the collision that has made the Himalayas the tallest mountains on earth. Burma is on the eastern edge of this zone. It is subject to earthquakes as India slides past. (See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* Death toll of Myanmar's earthquake rises to 74, 111 people injured (Xinhua 3/26/11))
* Burma earthquake hits faded drug area (Christian Science Monitor 3/24/11)
3/11/2011 Sendai, Japan Earthquake
Updated 5/14/11
The east coast of Japan was hit by a 9.0 Magnitude earthquake on March 11,2011 at 05:46UTC (2:46 pm local time), that caused major damage in the northeastern part of the country. Severe shaking lasted over 2 1/2 minutes. The epicenter was undersea off the coast of Honshu, Japan's largest island, 230 miles northeast of Tokyo, 80 miles from the city of Sendai, which sustained the worst damage. Sendai is the largest city in the area, with over 1 million people. The northeastern prefectures of Miyagi, Iwate and Fukushima were the worst hit. Over 300 bodies were found along the coast in that city alone immediately after the tsunami. The final number killed is estimated at about 25,000. As of May 13, 2011 the official toll is 15,019 dead, 9056 missing two months after the quake,5,282 injured,88,873 houses damaged. 440,000 people were evacuated. Two months later 100,000 were still in shelters. Damage from the quake is expected to reach $230 billion. The Japanese economy will suffer from the disaster, but as reconstruction efforts, which could last 5 years, get underway it should provide a stimulus.
Strong shaking and some damage in Tokyo was dwarfed by the damage further north. Initial relief assistance was provided by the military. A Japanese relief team that had been helping after the quake in New Zealand was called home. International teams are offering their help in rescue efforts. The US military has many bases in Japan and has mobilized resources to help. Much of the initial rescue work was done with helicopters, since many roads were impassable and many areas were submerged in seas of mud and standing water left from the tsunami. Temperatures were near or below freezing at night in the days after the quake, with many left homeless. Then it got colder and started snowing. It took days for rescue crews to reach some areas. 380,000 were living in shelters in school gymnasiums with little heat due to fuel and electricity shortages and short rations food. People remained generally calm even under very difficult circumstances. It was difficult to get supplies into these areas and the government is overwhelmed. People are being urged to leave the northeast and go to other parts of Japan but with transportation systems inoperable and little available fuel, it is unclear how large numbers can be evacuated.
According to the USGS list of the largest earthquakes, this was the 4th largest earthquake in the world since 1900. A tsunami was generated that flooded coastal areas of Japan and caused tsunami warnings throughout the Pacific. Damage from the tsunami was extensive with 30 foot waves reaching sometimes as far as 6 miles inland. There was little warning, 15 to 30 minutes, for the areas nearest the epicenter. Many of the dead and missing are believed to be from the tsunami. News cameras show a wall of water, churning with mud and debris advancing inexorably over the land, swallowing everything in its path. Fishing boats, cars, lumber, even whole houses are caught up and carried along. Once caught in the fierce currents, it is almost impossible to escape. A giant whirlpool was filmed off the coast, that dwarfed a boat caught in it. Afterwards all that was left was mud, standing water and debris that is hardly recognizable as having been a city.
Although the destruction in the quake area is very bad, it will not rival the 2004 Indian Ocean tsunami for destructiveness. In that case, there were large populations living on the coast of the Indian Ocean, all of which were in range of the destructive tsunami waves. Tsunami warnings were sent throughout the Pacific and people in the Philippines, Indonesia and as far away as the west coast of the United States were evacuated from coastal areas. The tsunami waves in Hawaii were about 6 feet and caused some damage but no injuries. There was damage to boats in marinas in Santa Cruz and Crescent City, California and Seaside Oregon. One man in Crescent City was swept out to sea while he was photographing the waves at a beach during the second tsunami surge two hours after the first one hit. Crescent City was also hit hard, with 11 people killed, by the 1964 tsunami after the Anchorage, Alaska quake.
The Japanese transportation system was brought to a halt with buses and trains unable to operate. Four trains in the northeast are unaccounted for, with fears that they were swept away by the tsunami. A ship with 100 passengers was reported missing. Power was knocked out over large areas. Over 1 million people are without drinking water. Store shelves are bare as people bought what they could get and suppliers are unable to deliver more. Roads became impassable with large cracks from the quake or clogged with traffic as hundreds of thousands tried to leave the affected area. The government advised people to stay where after the quake they were if they were in a safe place. Large numbers of people were stranded in Tokyo and other cities unable to get home. many slept in shelters. Oil refineries caught fire, as were parts of the hardest hit cities. Under these circumstances, there is little that firefighters can do. Large areas of the city of Kesennuma, a city of 74,000 were burning. One third of that city was submerged. Iwate, with 23,000 people was largely destroyed. Whole villages have been reportedly washed away. Millions of people lost power and 4 days later 850,000 were still without electricity and 1.5 million still had no water.
Earthquakes are common in Japan, although this is the strongest one in recorded history there. Buildings are designed to sway, rather than collapse, with building codes reflecting the latest anti-quake techniques. The results of these efforts could be seen in Tokyo, where most buildings rode out the strong shaking without structural damage. An earthquake warning system gave a few precious seconds warning to many before the quake struck, allowing people to take cover. Two days after the quake, transportation was moving again in Tokyo and life was returning to normal. It will be a long time before the same can be said of the north.
Despite the severity of the quake, most of the deaths were from the tsunami. Building codes designed to protect against earthquakes worked very well despite the unprecedented size of this one. Many less powerful earthquakes have killed many times the number that died in this one because buildings were not built to resist them.
The scale of destruction from the tsunami was tremendous. The areas it hit were covered with mud and the debris of the cities that were inundated. One estimate said that the disaster produced a century worth of garbage. The government is struggling to figure out how to dispose of it all. There are many challenges including where to dump it all. New dump sites were established but they are filling up quickly. Nobody seems to be prepared to salvage ships that have been washed up on top of the debris of the cities. The clean up is expected to take years.
Five nuclear reactors at two power plants in Fukushima Prefecturate shut down automatically following the quake but the combination of the quake and tsunami cut off power needed to keep the cooling systems operating and disabled the backup diesel generators, which were located in the basement and flooded in the tsunami. A week after the quake, emergency crews may have a new power line in operation. This may help efforts to cool the stricken reactors. The worst hit plant is the Fukushima Daiichi plant, which has 6 reactors. They have all seen serious damage to their cooling systems. The scope and strength of this quake has strained the ability to recover. In the week following the quake there were hydrogen explosions at these plants and at least 2 fires. 170,000 people in a 12 mile radius around the Fukushima plants were evacuated. Those within 19 miles were advised to stay indoors. The US government advised Americans within 50 miles to leave the area if possible, or remain inside. The government attributes the explosions to hydrogen buildup in the cooling system and denies reports of a core meltdown. However, it has become apparent that parts of the reactor cores did melt. Radiation levels outside the plant are many times the normal background level, limiting the ability of workers to bring the reactors or spent fuel under control. the greatest danger is from spent fuel stored at the plant because it is not contained as well as the reactor core. Despite heroic efforts by plant workers radiation releases continued in the weeks following the quake. In the worst case scenario, there is a danger of a meltdown of fuel in any of these reactors that would release large amounts of radiation, as bad as, or worse than Chernobyl. Iodine tablets were distributed to those nearest the plants as a precaution to ameliorate the effects of larger radiation exposure, should that occur. Iodine taken before exposure can prevent the absorption of radioactive iodine, especially important for children. There has been a run on iodine pills worldwide amid fears of large scale radiation releases, despite government statements saying that this is not necessary for people far away. Workers were flooding the cores and spent fuel with sea water in a last ditch effort to cool it down. This has led to radioactive water leaking both within the plant and escaping into the sea. In all 11 of the 54 nuclear reactors in Japan have been shut down, leading to shortages of electricity, even in area that did not lose power. The accident is causing Japan to re-evaluate its heavy reliance on nuclear power. 30% of Japan's energy comes from nuclear. Power is being slowly restored to cities but smaller towns will have to wait longer. Some companies have curtailed production to conserve power. Foreign countries urged their citizens to leave Japan.
There have been frequent large aftershocks. In the 2 days following the quake there were over 85 quakes greater than 5.0 Magnitude, more than 20 over 6.0 M. After 4 days that number has climbed to over 100. Eyewitnesses reported quakes continuing so frequently that it seemed that they were continuous. These would all be considered large quakes capable of causing damage under any circumstances. The largest was 7.1 M. on March 11. The aftershocks continued, though not as frequently, for weeks. By April 7 there had been 136 aftershocks greater than 5.0 M. On April 7th there was another 7.1M aftershock. Even before the major quake there were foreshocks for a couple of days. On March 9, the same area was hit by a 7.1 M quake. This graphic animation shows the quake and aftershocks. The larger the circle, the larger the quake. It starts a few days before. Note the date and time at the bottom right.
The earthquake was the result of subduction of the Pacific Plate beneath the North American Plate. Japan is extremely prone to earthquakes because it is located at the intersection of four major tectonic plates, the Pacific Plate, The Eurasian Plate, The Phillipine Plate and the North American Plate. Despite its name, the North American Plate actually extends beyond Alaska north of the Pacific and into Siberia. An arm of the plate drops down to include northern Japan, sandwiched between the Pacific and the mainland of Asia, specifically the Russian Far East near Vladivostok, which is on the Eurasian Plate. Subduction quakes occur when plates, pieces of the earth's crust, collide, forcing one beneath the other. This type of quake has the potential to be among the largest earthquakes on earth. Generally, the continental plate will ride up over the oceanic plate in this situation. This earthquake resulted in the Japan's largest island of Honshu moving 8 feet to the east, overriding the floor of the Pacific Ocean. A large subduction quake will sometimes displace enough water when a large section of ocean floor suddenly slips under the over-riding plate to cause a tsunami. The size of the tsunami depends on the conditions at the epicenter and can be hard to predict. The destructiveness also depends on how close to populated areas the quake occurs. In this case there was large coastal populations nearby.
(See the Plate Tectonics page for a maps of the tectonic plates and more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* Nuclear emergency declared at quake-damaged reactor (USA Today 3/11/2011)
* Japan evacuates 50,000 after nuclear power plant explosion (LA Times 3/12/2011)
* Google Resources Page on the Japanese Earthquake and Tsunami
* Quake clean-up continues as death toll grows (ABC Australia 3/18/11)
* Cable reaches Japan nuclear plant (BBC 3/17/2011)
* Pictures (BBC 3/11/2011)
* Japan devastated by 8.9-magnitude quake, tsunami (Washington Post 3/11/2011)
* 10K dead in Japan amid fears of nuclear meltdowns (Seattle Times 3/13/2011)
* Death toll rises, stocks plunge, foreigners flee as nuclear crisis escalates (Washington Post 3/15/2011)
* Factbox: Japan disaster in figure (Reuters 3/15/2011)
* Japan begins quake relief mission (BBC 3/11/2011)
* Japan damage could reach $235 billion, World Bank estimates (LA Times 3/21/2011)
* Strongest aftershock since tsunami rattles northeast Japan; 2 dead, widespread power outages (Washington Post 4/7/2011)
* Japan earthquake: Dealing with mountains of debris (BBC 5/14/2011)
*Listen to Japan's massive quake (The Lookout-A Y News Blog 3/18/2011)
* Sendai Tsunami through Western Eyes (Facebook)
3/10/11 Yunaan, China Quake
Updated 3/27/2011
At 04:58 UTC(11:58 AM local time) a 5.4M quake in southern Yunaan province in China, near the border with Burma caused extensive damage. It was centered 221 miles NE of Mandalay, Burma, 350 miles north of Rangoon, Burma. 25 people were killed, 250 injured and over 6,000 buildings damaged in that quake. The quake was widely felt throughout Southeast Asia. It is in the same general area as the subsequent March 24, 2011 quake centered in northern Burma.
The quake was caused by the movement of the Indian Plate NNE into the Eurasian Plate at the rate of 45mm(1.77 inches)/yr. This is the collision that has made the Himalayas the tallest mountains on earth. Burma is on the eastern edge of this zone. It is subject to earthquakes as India slides past. (See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* China earthquake kills 24 and destroys over 1,000 buildings(Christian Science Monitor 3/10/11)
At 04:58 UTC(11:58 AM local time) a 5.4M quake in southern Yunaan province in China, near the border with Burma caused extensive damage. It was centered 221 miles NE of Mandalay, Burma, 350 miles north of Rangoon, Burma. 25 people were killed, 250 injured and over 6,000 buildings damaged in that quake. The quake was widely felt throughout Southeast Asia. It is in the same general area as the subsequent March 24, 2011 quake centered in northern Burma.
The quake was caused by the movement of the Indian Plate NNE into the Eurasian Plate at the rate of 45mm(1.77 inches)/yr. This is the collision that has made the Himalayas the tallest mountains on earth. Burma is on the eastern edge of this zone. It is subject to earthquakes as India slides past. (See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* China earthquake kills 24 and destroys over 1,000 buildings(Christian Science Monitor 3/10/11)
2/21/11 Christchurch New Zealand Quake
Updated 2/26/2011
The city of Christchurch, New Zealand was hit by a 6.3 M earthquake Monday, February 21, 2011 at 23:51:42 UTC (12:51 pm Tuesday Feb 22, 2011 local time). Damage has been extensive, with 144 confirmed dead and 200 missing and feared dead. As many as 1/3 of the buildings in downtown Christchurch may have to be demolished due to quake damage. The quake struck in the early afternoon when the city was at its busiest. Most of the worst damage was to older brick buildings. Newer construction generally fared better. The worst casualties occured when Christchurch Cathedral, the Pyne Gould Guinness building, and the Canterbury Television (CTV) building collapsed. Among the missing at CTV are a number of students at a school housed in the building. Rescuers have been searching for survivors but now, 5 days after the quake, they are saying that they are unlikely to find any more people alive.
Christchurch is New Zealand's second largest population center with a population of 390,000. The earthquake's epicenter was only 6 miles from the city center and had a shallow focus, only about 3 miles deep. Both of these facts contributed to the large amount of damage, as did the number of older brick building, which cannot withstand large quakes. International rescue teams are aiding in the search for survivors. The city lost power and five days after the quake, 62,000 homes still have no water, while 100,000 have lost their sewer connections. 800 portable toilets hardly seem like enough meet the need and counter the threat of disease. The quake damage casts doubt on the ability of Christchurch to host the Rugby World Cup in September.
According to the USGS, this quake is actually the largest aftershock of the 7.0 M September 3, 2010 Darfield, New Zealand earthquake. The September quake caused remarkably little damage, considering its size. However buildings in Christchurch had still not been repaired when the February quake occurred. The February 21 quake was so much more damaging due to its proximity to the city of Christchurch and a shallower focus. This highlights once again, as in Haiti, the difference location can have in determining the destructiveness of a quake. Since the September earthquake there have been 6 aftershocks in Christchurch with a magnitude over 5.0. Shake maps of the September 2010 andFebruary 2011 quakes show heavy to moderate shaking over a larger area for the September quake, while the February quake had very heavy shaking right in Christcurch.
New Zealand is in a very active earthquake zone. In the 15 years between 1992 and 2007, New Zealand experienced over 30 earthquakes of magnitude 6 or more. This is because the islands of New Zealand are located on the boundary of two tectonic plates. The Pacific Plate is moving towards the Northwest. You can see this movement by looking at earthquake faults on other edges of the Pacific Plate. The San Andreas Fault in California trends towards the northwest as the Pacific Plate slides along the edge of the North American Plate. In Alaska this same northwest motion causes subduction quakes in Alaska. The 1964 Anchorage quake was one result. The arc of the Aleutian archipelago is another. Finally, the Hawaiian Islands describe a line from the northwest to the southeast showing the progress of the Pacific Plate as it has passed over a hot spot that has generated a series of volcanoes that mark its passage. Meanwhile the Australian Plate is moving towards the northeast. This plate subducts beneath the Sunda Plate, which is a small continental plate next to the larger Eurasian Plate to the north and west of New Zealand, causing the devastating Sumatra earthquakes. These two plate motions result in the Pacific Plate subducting beneath the Australian Plate. The recent earthquakes have been shallow, towards the western edge of the subduction zone. As the Pacific Plate is forced under the Australian quake it descends towards the earth's mantle and earthquakes, which occur at the boundary between the plate are deeper and stronger. In the South Island, these occur along the Alpine Fault, which is capable of quakes as strong as anywhere on earth. This fault is responsible for raising the New Zealand Alps, and indeed, the islands of New Zealand. It has not seen a major rupture since 1717 and seismologists give it a high probability of a 8.0 M within the next 40 years. The recent quakes, destructive as they have been, have not relieved the strain on this fault. The destructive effects of such a quake will be mollified because it will be deeper and further to the west, away from the major population centers.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake. The New Zealand Earthquake Information Page is also loaded with information
See also the following news stories:
* Google Search Page - New Zealand Earthquake 2011
* Third of Christchurch buildings 'could face demolition' (BBC 2/26/11)
*New Zealand earthquake toll surges to 145 dead (Montreal Gazette 2/26/11)
*New Zealand – Earthquake Fact Sheet #1, Fiscal Year (FY) 2011 (USAID Reliefweb 2/25/11)
The city of Christchurch, New Zealand was hit by a 6.3 M earthquake Monday, February 21, 2011 at 23:51:42 UTC (12:51 pm Tuesday Feb 22, 2011 local time). Damage has been extensive, with 144 confirmed dead and 200 missing and feared dead. As many as 1/3 of the buildings in downtown Christchurch may have to be demolished due to quake damage. The quake struck in the early afternoon when the city was at its busiest. Most of the worst damage was to older brick buildings. Newer construction generally fared better. The worst casualties occured when Christchurch Cathedral, the Pyne Gould Guinness building, and the Canterbury Television (CTV) building collapsed. Among the missing at CTV are a number of students at a school housed in the building. Rescuers have been searching for survivors but now, 5 days after the quake, they are saying that they are unlikely to find any more people alive.
Christchurch is New Zealand's second largest population center with a population of 390,000. The earthquake's epicenter was only 6 miles from the city center and had a shallow focus, only about 3 miles deep. Both of these facts contributed to the large amount of damage, as did the number of older brick building, which cannot withstand large quakes. International rescue teams are aiding in the search for survivors. The city lost power and five days after the quake, 62,000 homes still have no water, while 100,000 have lost their sewer connections. 800 portable toilets hardly seem like enough meet the need and counter the threat of disease. The quake damage casts doubt on the ability of Christchurch to host the Rugby World Cup in September.
According to the USGS, this quake is actually the largest aftershock of the 7.0 M September 3, 2010 Darfield, New Zealand earthquake. The September quake caused remarkably little damage, considering its size. However buildings in Christchurch had still not been repaired when the February quake occurred. The February 21 quake was so much more damaging due to its proximity to the city of Christchurch and a shallower focus. This highlights once again, as in Haiti, the difference location can have in determining the destructiveness of a quake. Since the September earthquake there have been 6 aftershocks in Christchurch with a magnitude over 5.0. Shake maps of the September 2010 andFebruary 2011 quakes show heavy to moderate shaking over a larger area for the September quake, while the February quake had very heavy shaking right in Christcurch.
New Zealand is in a very active earthquake zone. In the 15 years between 1992 and 2007, New Zealand experienced over 30 earthquakes of magnitude 6 or more. This is because the islands of New Zealand are located on the boundary of two tectonic plates. The Pacific Plate is moving towards the Northwest. You can see this movement by looking at earthquake faults on other edges of the Pacific Plate. The San Andreas Fault in California trends towards the northwest as the Pacific Plate slides along the edge of the North American Plate. In Alaska this same northwest motion causes subduction quakes in Alaska. The 1964 Anchorage quake was one result. The arc of the Aleutian archipelago is another. Finally, the Hawaiian Islands describe a line from the northwest to the southeast showing the progress of the Pacific Plate as it has passed over a hot spot that has generated a series of volcanoes that mark its passage. Meanwhile the Australian Plate is moving towards the northeast. This plate subducts beneath the Sunda Plate, which is a small continental plate next to the larger Eurasian Plate to the north and west of New Zealand, causing the devastating Sumatra earthquakes. These two plate motions result in the Pacific Plate subducting beneath the Australian Plate. The recent earthquakes have been shallow, towards the western edge of the subduction zone. As the Pacific Plate is forced under the Australian quake it descends towards the earth's mantle and earthquakes, which occur at the boundary between the plate are deeper and stronger. In the South Island, these occur along the Alpine Fault, which is capable of quakes as strong as anywhere on earth. This fault is responsible for raising the New Zealand Alps, and indeed, the islands of New Zealand. It has not seen a major rupture since 1717 and seismologists give it a high probability of a 8.0 M within the next 40 years. The recent quakes, destructive as they have been, have not relieved the strain on this fault. The destructive effects of such a quake will be mollified because it will be deeper and further to the west, away from the major population centers.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake. The New Zealand Earthquake Information Page is also loaded with information
See also the following news stories:
* Google Search Page - New Zealand Earthquake 2011
* Third of Christchurch buildings 'could face demolition' (BBC 2/26/11)
*New Zealand earthquake toll surges to 145 dead (Montreal Gazette 2/26/11)
*New Zealand – Earthquake Fact Sheet #1, Fiscal Year (FY) 2011 (USAID Reliefweb 2/25/11)
10/25/2010 Metawai, Sumatra Tsunami and Quake
Updated 10/29/2010
A 7.7M Undersea earthquake triggered a 10 foot tsunami on Monday October 25, 2010 at 2:42 PM UTC (9:42 PM local time). 400 people have been confirmed dead and another 300 missing. It appears unlikely that any of these have survived. A government official said that they most likely had been swept out to sea or buried in the sand. The epicenter of the quake was off the southwest coast of Sumatra, 150 miles west of the city of Benkulu and 175 miles south of Padang. This area is 500 miles from Jakarta. The quake was felt as far away as Singapore. The tsunami was the main cause of the damage and casualties in the Mentawai Islands, a string of islands about 100 miles off the Sumatra Coast. North Pagai Island is 50 miles from the epicenter of the quake and took the brunt of the tsunami. Whole villages were leveled as the tsunami came ashore without warning. Indonesia has been installing tsunami warning systems following the 2004 tsunami that swept across the Indian Ocean killing over 200,000 people, half of them in Indonesia. However this quake was located close to shore and the tsunami arrived within minutes, before people could evacuate. It also appears that a buoy crucial to the warning system was not working at the time.
Aid has been hampered by bad weather and rough seas, which is making it difficult for rescuers to reach all the affected areas. Access is generally by sea in this island chain. Three Indonesian ships loaded with supplies arrived within three days but have had difficulty reaching those in need.
The quake was caused by the Australian plate subducting under the neighboring Sunda Plate to the Northeast. It was only the most recent of a series of quakes along the southwest coast of Sumatra that makes this the most seismically active area in the world. The current series began with the huge Acheh earthquake and tsunami in 2004 and has been working its way down the coast with major quakes every few years in different sections of this fault zone. As one area it builds up pressure on the adjoining areas. Actually this is a continual process since the motivating factor is the pressure of the Australian plate moving towards and forcing its way under the overlying Sunda plate. This will continue to create large quakes as stick and then slip past eachother. An undersea quake can displace enough of the seafloor to cause a tsunami. In general the larger the quake, the larger the tsunami, but there are a lot of factors can affect it. Theses factors are not all that well understood, especially in the immediate aftermath of a quake when the need to know whether to expect a tsunami is the greatest.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* Indonesia tsunami relief slowed by bad weather(BBC 10/29/10)
* Indonesian tsunami zone welcomes aid shipments (BBC 10/28/10)
* In Pictures: Indonesian Tsunami (BBC 10/27/10)
*Animated Guide - Tsunamis(BBC 9/8/08)
A 7.7M Undersea earthquake triggered a 10 foot tsunami on Monday October 25, 2010 at 2:42 PM UTC (9:42 PM local time). 400 people have been confirmed dead and another 300 missing. It appears unlikely that any of these have survived. A government official said that they most likely had been swept out to sea or buried in the sand. The epicenter of the quake was off the southwest coast of Sumatra, 150 miles west of the city of Benkulu and 175 miles south of Padang. This area is 500 miles from Jakarta. The quake was felt as far away as Singapore. The tsunami was the main cause of the damage and casualties in the Mentawai Islands, a string of islands about 100 miles off the Sumatra Coast. North Pagai Island is 50 miles from the epicenter of the quake and took the brunt of the tsunami. Whole villages were leveled as the tsunami came ashore without warning. Indonesia has been installing tsunami warning systems following the 2004 tsunami that swept across the Indian Ocean killing over 200,000 people, half of them in Indonesia. However this quake was located close to shore and the tsunami arrived within minutes, before people could evacuate. It also appears that a buoy crucial to the warning system was not working at the time.
Aid has been hampered by bad weather and rough seas, which is making it difficult for rescuers to reach all the affected areas. Access is generally by sea in this island chain. Three Indonesian ships loaded with supplies arrived within three days but have had difficulty reaching those in need.
The quake was caused by the Australian plate subducting under the neighboring Sunda Plate to the Northeast. It was only the most recent of a series of quakes along the southwest coast of Sumatra that makes this the most seismically active area in the world. The current series began with the huge Acheh earthquake and tsunami in 2004 and has been working its way down the coast with major quakes every few years in different sections of this fault zone. As one area it builds up pressure on the adjoining areas. Actually this is a continual process since the motivating factor is the pressure of the Australian plate moving towards and forcing its way under the overlying Sunda plate. This will continue to create large quakes as stick and then slip past eachother. An undersea quake can displace enough of the seafloor to cause a tsunami. In general the larger the quake, the larger the tsunami, but there are a lot of factors can affect it. Theses factors are not all that well understood, especially in the immediate aftermath of a quake when the need to know whether to expect a tsunami is the greatest.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* Indonesia tsunami relief slowed by bad weather(BBC 10/29/10)
* Indonesian tsunami zone welcomes aid shipments (BBC 10/28/10)
* In Pictures: Indonesian Tsunami (BBC 10/27/10)
*Animated Guide - Tsunamis(BBC 9/8/08)
4/13/10 Quinghai, China Quake
Updated 04/16/2010
The 6.9 Magnitude earthquake shook Yushu in southern Quinghai province in western China on Tuesday, April 13, 2010 at 23:49:38 UTC, 7:49 AM local time. This area is near Tibet, 1200 miles SW of Bejing. 1,144 people have been confirmed dead with 11,474 injured. Many building were completely destroyed. Residents are either afraid to spend the night in their homes, or have no homes left to return to. 15,000 houses were destroyed. Three days after the quake, tents and other aid is being distributed by the Chinese government. There were some complaints that aid was slow to arrive.
One thing that makes the rescue efforts more difficult is the high altitude, over 13,000 feet. Rescue workers from other parts of China are limited by the unaccustomed thin air. Nighttime temperatures have been dropping below freezing, with forecasts of wind and sleet. There is a small airport but it does not have refueling facilities. Planes must carry fuel for the round trip, which limits their cargo capacity.
Yushu is on the Tibetan Plateau and is populated by Tibetans. The 800 year old Taklung monastery was so badly damaged that rescue teams were unable to work there because of the danger from further collapse. The Chinese Premier, Wen Jiabao, visited the site and promised to rebuild the monastery. Monks have been prominent in the rescue effort.
This quake occurred in the interior of the Tibetan Plateau, which is being lifted and pushed to the east by the force of the collision between India and Asia. Over the past few million years, the Indian Subcontinent has been propelled across the Indian Ocean and slammed into southern Asia. The force of this collision has raised the Himalayan mountains along with the Tibetan Plateau behind them. This quake is the result of adjustments within the earth's crust as a result of the pressure of the collision a few hundred miles to the south.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
*Chinese rescue effort builds after Quinghai quake (BBC 4/16/10)
*Earthquake survivors in Tibet mourn loss of treasured heritage (Guardian 4/16/10)
*China quake death toll passes 1,000 (BBC 4-16-10)
*In Pictures: China's quake (BBC)
The 6.9 Magnitude earthquake shook Yushu in southern Quinghai province in western China on Tuesday, April 13, 2010 at 23:49:38 UTC, 7:49 AM local time. This area is near Tibet, 1200 miles SW of Bejing. 1,144 people have been confirmed dead with 11,474 injured. Many building were completely destroyed. Residents are either afraid to spend the night in their homes, or have no homes left to return to. 15,000 houses were destroyed. Three days after the quake, tents and other aid is being distributed by the Chinese government. There were some complaints that aid was slow to arrive.
One thing that makes the rescue efforts more difficult is the high altitude, over 13,000 feet. Rescue workers from other parts of China are limited by the unaccustomed thin air. Nighttime temperatures have been dropping below freezing, with forecasts of wind and sleet. There is a small airport but it does not have refueling facilities. Planes must carry fuel for the round trip, which limits their cargo capacity.
Yushu is on the Tibetan Plateau and is populated by Tibetans. The 800 year old Taklung monastery was so badly damaged that rescue teams were unable to work there because of the danger from further collapse. The Chinese Premier, Wen Jiabao, visited the site and promised to rebuild the monastery. Monks have been prominent in the rescue effort.
This quake occurred in the interior of the Tibetan Plateau, which is being lifted and pushed to the east by the force of the collision between India and Asia. Over the past few million years, the Indian Subcontinent has been propelled across the Indian Ocean and slammed into southern Asia. The force of this collision has raised the Himalayan mountains along with the Tibetan Plateau behind them. This quake is the result of adjustments within the earth's crust as a result of the pressure of the collision a few hundred miles to the south.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
*Chinese rescue effort builds after Quinghai quake (BBC 4/16/10)
*Earthquake survivors in Tibet mourn loss of treasured heritage (Guardian 4/16/10)
*China quake death toll passes 1,000 (BBC 4-16-10)
*In Pictures: China's quake (BBC)
March 8, 2010 Turkey Earthquake
Updated 03/09/2010
At 02:32 UTC (4:32 AM local time) on March 8, 2010, Eastern Turkey was hit by a 6.1 M earthquake. The epicenter was near Bingol, Turkey, 390 miles east of Ankara. Although the quake was not as strong as others in the news, many houses collapsed and 51 people were killed. The main building material in the area is mud bricks, which do not stand up well to earthquakes. The government pledged to provide safer houses, but despite a long history of earthquakes and previous similar pledges, this area has yet to get any. It is customary for people to keep their livestock on the ground floor of their houses and live upstairs. When houses collapsed, there was also a toll taken on the animals, which provide a significant portion of people's income.
The quake was caused by the stresses resulting from the collision of the Arabian Plate with the Eurasian Plate. In this process much of Turkey, the Anatolian block, is being squeezed off to the west. We see the quakes as a reflection of the plates of Earth's crust being jostled, bumping into each other, rubbing against each other and in the process knocking down buildings and causing so much suffering. Turkey has seen many devastating quakes over the years. In 1999, a quake in a different part of the country showed that even good building don't help if they aren't enforced.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* Strong earthquake hits eastern Turkey(BBC 3/8/10)
*Turkey pledges safer homes after quake(AP 3/8/10)
At 02:32 UTC (4:32 AM local time) on March 8, 2010, Eastern Turkey was hit by a 6.1 M earthquake. The epicenter was near Bingol, Turkey, 390 miles east of Ankara. Although the quake was not as strong as others in the news, many houses collapsed and 51 people were killed. The main building material in the area is mud bricks, which do not stand up well to earthquakes. The government pledged to provide safer houses, but despite a long history of earthquakes and previous similar pledges, this area has yet to get any. It is customary for people to keep their livestock on the ground floor of their houses and live upstairs. When houses collapsed, there was also a toll taken on the animals, which provide a significant portion of people's income.
The quake was caused by the stresses resulting from the collision of the Arabian Plate with the Eurasian Plate. In this process much of Turkey, the Anatolian block, is being squeezed off to the west. We see the quakes as a reflection of the plates of Earth's crust being jostled, bumping into each other, rubbing against each other and in the process knocking down buildings and causing so much suffering. Turkey has seen many devastating quakes over the years. In 1999, a quake in a different part of the country showed that even good building don't help if they aren't enforced.
(See the Plate Tectonics page for more information on these processes.) The US Geological Survey (USGS) is an invaluable resource in understanding and tracking earthquakes. See the USGS summary of this quake.
See also the following news stories:
* Strong earthquake hits eastern Turkey(BBC 3/8/10)
*Turkey pledges safer homes after quake(AP 3/8/10)
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