5/27/06 Java Quake

Updated 7/8/06

At 5:54 AM local time Saturday Morning May 27, 2006 (22:53 GMT Friday) a 6.3 Magnitude earthquake hit near the south coast of central Java in Indonesia. It was centered near the major city of Yogyakarta, 275 miles SE of Jakarta. Yogyakarta, (sometimes spelled Jogjikarta, or Jogji) is one of the major cities of Indonesia. About 5 million people live within 50 kilometers of the epicenter. A point of interest is that this is one of the few places that the pre-colonial government structure of a sultanate has survived. It is not known how the 18th Century Sultan's palace, a large architecturally significant building in the center of the city, has fared.

5,700 people have been killed and 36,300 injured according to the Indonesian government. People reported that this was by far the biggest quake that they had ever experienced. There was very extensive damage to buildings, especially in the hardest hit area south of the city in the Bantul area where the epicenter was located. Electricity and communications were been knocked out in the affected areas. The airport was closed due to damage to the runway and emergency flights had to come into the nearby city of Solo.

Hospitals were overwhelmed with the injured with temporary medical clinics set up in the streets. International aid has been offered by Russia, the Europeon Union and others. UNICEF said it is preparing emergency supplies and has sent staff to Yogyakarta. It has emergency supplies of tents, hygiene kits, health kits and school supplies available to be sent to the earthquake zone. The supplies include 9,000 tarpaulins, 850 hygiene kits, 1,165 small tents, 753 large tents, 4,000 lanterns, 160 collapsible water tanks, 1,707 school kits, 50 school tents, 152 recreation kits, and 90 school-in-a-box school supplies

Thousands of people fled inland immediately after the quake to escape a possible tsunami. This was a lesson learned after the 2004 tsunami. Although this quake was very much smaller and did not pose a tsunami threat, it was not immediately clear to people on the scene that this was the case. This self evacuation is exactly what earthquake experts recommend to people living in coastal areas who experience an earthquake. As we saw in 2004, waiting for official instructions would take too long and could prove fatal if there were to be a tsunami. They say that if you live near the coast and feel an earthquake, you should immediately move inland, as people did in this case.

The Mount Merapi volcano is just north of that area. Merapi has been erupting during the last few weeks. Many people have been evacuated from the volcano slopes for fear of a larger eruption with catastrophic landslides or lava flows. The earthquake appears to be unrelated to the eruptions, caused rather by normal tectonic processes but may be responsible for increased volcanic activity afterwards.

This quake was caused by the same plate interactions responsible for the 2004 earthquake and tsunami, although this quake was smaller (maybe 1/1000th as strong) than in 2004 and about 1200 miles to the south and east of that quake. This quake did not cause a tsunami. In general, the Indonesian archipeligo, especially Sumatra and Java, are formed by the subduction of the Australian Plate beneath the Eurasian plate. The actual situation is more complicated due to the many adjoining plates in that area of the world. These plate interactions make these islands among the most active areas of the world for both earthquakes and volcanos. Earthquakes are the result of the surface plates rubbing against eachother in a jerky fashion as one plate pushes itself beneath another. Volcanos occur as the subducting plate is forced down into the earth's interior. When it hits the mantle the rock melts into magma, some of which rises to the surface in volcanos.

(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.

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10/8/2005 Kashmir Quake

Updated 10/29/2005

The strongest earthquake to hit Pakistan in over a century hit in the middle of the morning on Saturday October 8 at 8:50 AM local time (03:50 UTC). With a magnitude of 7.6, it caused extensive damage and thousands of casualties throughout Kashmir. The epicenter was near the capital of Pakistani administered Kashmir, Muzaffarabad.

Death tolls have been estimated at over 79,000, with thousands more injured and, according to the UN, 3 million in need of shelter. Many villages and towns have been reduced to rubble. At least 400 children were killed when two schools collapsed. Whole families have been wiped out. An upscale apartment building in Islamabad, 60 miles away collapsed. With over a dozen aftershocks of at least Magnitude 5.5 in the first week after the quake, many were afraid to sleep inside, despite the bad weather. People have been arriving in the cities, having walked from their mountain villages where they say no aid had arrived after days of waiting.

Pakistani President Pervez Musharraf told the BBC that Pakistan needed "massive cargo helicopter support" and aid supplies. Aid has been offered from many countries. The US has offered helicopters, which are in need because rescue vehicles can't reach many areas because landslides have blocked roads. People were digging through the rubble by hand in heavy rain to try to find survivors. Ten days after the quake the Pakistani government said they had reached most, but not all the areas affected. However, they estimate that 20% of the affected area hadn't receives any shelter or supplies. Even 3 weeks afterwards, the World Food Programme estimates that 500,000 people haven't received any aid at all. The international community has provided 90 helicopters to help get supplies to remote areas and evacuate the wounded. Thousands of injured are still waiting for help in inaccessible areas. Helicopters cannot reach all of them due to high altitude, rugged terrain and bad weather. For many people, the only reliable way to get injured people out or supplies in, is on foot or mule. 30 field hospitals have been established but serious cases need to reach a major hospital in a city and that is still difficult. There are fears that people could develop gangrene due to lack of attention and that disease could spread due to lack of clean water and sanitary facilities.

An international donors conference pledged over $500 million dollars in aid, but only about 20% has been delivered so far. Meanwhile the UN is running out of funds for their efforts and will have to scale back if more money is not made available. The most serious problem, after the immediate rescue efforts, is lack of shelter. Many families are trying to stay on their land, but with the oncoming Himalayan winter, lack of adequate housing is a major problem.

Private charities who depend on individual contributions have noted a reduced level of giving from the United States, following the massive outpouring of donations for Hurricane Katrina victims last month and the tsunami last year. However, contributions and volunteers in India and Pakistan have been very substantial. In the Indian administered areas some of the first to respond were Kashmiri independence groups. Throughout the region, people have turned out to do whatever they can, even before the government has been able to reach many areas. Heavy rains have hampered relief efforts. Also hampering efforts has been a lack of coordination and organization of the relief. Mountain roads are being clogged by trucks bringing in supplies, making it difficult to evacuate the wounded. In some cases, roads that survived the quake, or had been repaired, are damaged by the heavy traffic.

One organization, Working Assets, is urging contributions specifically to rebuild schools, especially for girls, that were damaged. From their website: "One of the most heart-wrenching stories emerging from this catastrophe is that of the girls' school in the village of Ghari Habibibullah, Pakistan. There, 250 students were killed, more than 500 injured, and the school was completely demolished. Similar catastrophes happened in villages all over the region, such as Balakot. Girls' schools were often beacons of hope and implicit progress in a region dominated by fundamentalist Islam, and rebuilding these schools is likely to be at the bottom of the political agenda. So Working Assets has launched a campaign to support rebuilding girls' schools in Pakistan and India -- and we're asking for your help."

Most of the casualties have been in the Pakistani administered areas, but almost1400 have also died in Indian administered Kashmir. 5,000 were injured and 140,000 homeless. The Prime Minister and Congress Party leader, Sonia Gandhi, toured the area soon after the quake, but there have been complaints that aid was slow in coming.

The USGS reports : "Earthquakes and active faults in northern Pakistan and adjacent parts of India and Afghanistan are the direct result of the Indian subcontinent moving northward at a rate of about 40 mm/yr (1.6 inches/yr) and colliding with the Eurasian continent. This collision is causing uplift that produces the highest mountain peaks in the world including the Himalayan, the Karakoram, the Pamir and the Hindu Kush ranges. As the Indian plate moves northward, it is being subducted or pushed beneath the Eurasian plate. Much of the compressional motion between these two colliding plates has been and continues to be accommodated by slip on a suite of major thrust faults that are at the Earth�s surface in the foothills of the mountains and dip northward beneath the ranges. These include the Main Frontal thrust, the Main Central thrust, the Main boundary thrust, and the Main Mantle thrust. These thrust faults have a sinuous trace as they arc across the foothills in northern India and into northern Pakistan. In detail, the modern active faults are actually a system of faults comprised of a number of individual fault traces. In the rugged mountainous terrain, it is difficult to identify and map all of the individual thrust faults, but the overall tectonic style of the modern deformation is clear in the area of the earthquake; north- and northeast-directed compression is producing thrust faulting. Near the town of Muzaffarabad, about 10 km southwest of the earthquake epicenter, active thrust faults that strike northwest-southeast have deformed and warped Pleistocene alluvial-fan surfaces into anticlinal ridges. The strike and dip direction of these thrust faults is compatible with the style of faulting indicated by the focal mechanism from the nearby M 7.6 earthquake. "

(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.

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3/28/2005 Sumatra Quake

Updated 4/2/2005

This 8.7M quake was centered off the West coast of Northern Sumatra. Earthquakes over Magnitude 8 are classified as "Great" Earthquakes. "Great" quakes are relatively rare and usually very destructive. By comparison, this earthquake was considerably larger than the 1906 San Francisco earthquake and indeed larger than any seen in the US outside of Alaska. Of course damage from any quake is due to a number of factors including density of population, building methods and materials, local geology and the duration of shaking. This quake struck at 4:09 PM (GMT) or 11:09 PM local time. Shaking lasted 3 minutes, which is a long time for an earthquake. There have been at least 518 people confirmed killed and thousands displaced. A few people were pulled alive from the rubble after 4 days. Worst hit was the island of Nias, where electricity and water supplies have been disrupted. Roads and runways across the island have large cracks across them and are in many cases unusable. Also hard hit was the nearby island of Simeulue. Fires have raged unchecked with fire fighting equipment buried in rubble.

Aid has been arriving from around the world. Some teams were already in place in nearby Aceh from the December quake and tsunami. Some of the areas devastaed then have seen more damage from this quake. Tsunami warnings went out around the Indian Ocean and people were evacuated from coastal areas in Sri Lanka, India, Thailand, Malaysia and Indonesia. However this time there was no tsunami.

This earthquake occured on a neighboring section of the same subduction zone that caused the December 26, 2004 tsunami. Scientists had been concerned that that quake would increase the pressure on parts of the zone that had not moved and this appears to be what happened here. This map shows the relationship between these two quakes and two other quakes that have occured in the same area in the past. You can see quite clearly how different sections of this zone will move at different times.

(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. Here is the USGS report on this earthquake

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3/20/2005 Japan Quake

Updated 3/20/2005

This 6.4M quake hit 570 miles west of Tokyo, off the coast of the island of Kyushu, Japan at 01:53AM (GMT) or 10:53 AM local time. Some news reports rated the quake as a Magnitude 7, which would have been much more powerful than the 6.4 Magnitude reported by the USGS. Many buildings were damaged, utilities were cut off, 1 person was killed and another 250 were injured. Tall buildings swayed in Fukuoka. Numerous aftershocks have followed the main quake. Intial fears that the quake would generate a tsunami proved unfounded.

The damage from this quake was very much less than the Iranian quake of similar size just a month before. Hundreds of people died in that quake. Both areas are subject to frequent strong earthquakes, but Japan has done a much better job of preparing for the inevitable with strong earthquake resistant building codes. Even so, a large earthquake in an urban area can cause thousands of deaths and billions of dollars worth of damage, as demonstrated in Kobe.

Japan is subject to frequent earthquakes due to the interactions of the Pacific, Phillipines, North American and Eurasian Plates in this area of the world.

(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.

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2/22/2005 Kerman,Iran Quake

Updated 3/20/2005

This 6.4M quake hit Central Iran Tuesday, February 22, 2005 at 02:25AM (GMT) or 5:55 AM local time.

The epicenter was:
55 km (35 miles) NNW of Kerman, Iran
185 km (115 miles) NE of Sirjan, Iran
270 km (165 miles) ESE of Yazd, Iran
745 km (465 miles) SE of TEHRAN, Iran

According to the USGS at least 602 people were killed and 991 injured. The quake hit a rural area with no large cities, lessening the impact. Five villages were reported very heavily damaged with perhaps 50 more having substantial damage. Rescue efforts were somewhat hampered by heavy rains and freezing temperatures but there were also reports that rescue units were already on alert for fear that the rain would cause damage. Roads to some of the area have been blocked by landslides, making it difficult for needed heavy equipment to reach the scene. Numerous aftershocks kept many out of doors for fear of further damage to buildings. Most of the casualties were from collapsed buildings. Gas and electricity supplies have been disrupted and the government has asked people to limit use of mobile phones to allow better communications among emergency personnel. The Iranian government declared a national day of mourning for the dead.

The earthquake was caused by stresses generated by the northward movement of the Arbaian Plate into the Eurasian Plate at about 1 inch per year. This is sufficient to cause frequent quakes throughout Iran. The February 22 earthquake is 125 km northwest of the destructive earthquakes of June 11, 1981 (magnitude 6.6, approximately 3,000 deaths) and July 28, 1981 (magnitude 7.3, approximately 1,500 deaths) and about 250 km northwest of the devastating Bam earthquake of December 26, 2003 (magnitude 6.6, over 30,000 deaths).

(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.

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12/26/2004 Sumatra Earthquake and Tsunami

Updated 3/20/2005

At 9.0 Magnitude, this was the largest earthquake in the world since the 1964 Alaskan quake. It struck on December 26 at 6:58 AM local time (00:58 GMT). The epicenter was 255 km (160 miles) SSE of Banda Aceh, Sumatra, Indonesia 315 km (195 miles) W of Medan, Sumatra, Indonesia 1260 km (790 miles) SSW of BANGKOK, Thailand 1590 km (990 miles) NW of JAKARTA, Java, Indonesia.

Casualties have been very high, with over 283,000 dead, especially from the tsunami generated by the earthquake. The tsunami, reported as 15 - 20 feet high, fanned out over the Indian Ocean causing severe and sudden flooding in Sri Lanka, India, Thailand, Indonesia and other areas. Over a million people have been reported as homeless in Sri Lanka alone, at least 5 million were left without the basic necessities of life. Over 100,000 are reported dead in Indonesia. This tsunami was one of the largest ever in terms of casualties because it hit in heavily populated low lying coastal areas that were not well prepared. The lack of a warning system meant that most people were caught by surprise. It has been a long time since there has been a tsunami in this region. Unlike the Pacific Ocean, which has a well developed warning system, the Indian Ocean has no way to warn of an impending tsunami. Scientists knew as soon as the quake happened that it posed a danger of tsunami, but there was no way to get the word to the coastal areas in time. There were only a few minutes to a couple of hours between the quake and the tsunami. Communications were not up to the task.

The scope of this disaster is well beyond what is normal for even a strong earthquake. The tsunami hit 14 different countries, with severe damage in four (Indonesia, Thailand, India and Sri Lanka), spread out over thousands of miles. India reported that they had sufficient resources to provide needed aid in their own country and send some to Sri Lanka as well. Sri Lanka has a long coastline that suffered badly needs assistance, but with the interior undamaged can mobilize fairly well to receive and distribute aid. Indonesia is much worse off. They have to cope with quake damage and tsunami damage, as well as a less well developed infrastructure that make communications and travel difficult. There are shortages of petrol and machinery, such as forklifts that would make the relief effort easier.

People reported seeing the ocean pull back, exposing the sea floor and then return as a swift rise in the sea level, like an extremely high tide, inundating villages near the coast. The wave then pulled back, sucking houses, trees, people...everything in its path out to sea. These waves have a long period, so there are many minutes until the next wave hits. The process is similar to the ripples formed when a stone is thrown into water. Each successive wave carries more debris, causing more damage. The zone of damage extends up to 2 miles inland along the entire coast. Most buildings in this zone are severly damaged or destroyed, with a thick layer of mud covering everything. Food, water, electricity, and housing are all non existant or in short supply.

The area of the quake itself in Aceh province has seen severe damage from the earthquake and from the tsunami in coastal areas. Reports suggest that there may be over 100,000 dead in Sumatra alone. There have been reports of many buildings destroyed. Large amounts of international aid were desparately needed and relief supplies were sent from throughout the world. Some of the most severely affected areas did not receive any aid for a week after the disaster due to the huge need and difficulty of reaching remote areas. Observers repeatedly reported that the scope of the disaster was unbelievable, with almost complete destruction along hundreds of miles of coastal areas.

There have been many powerful aftershocks along the whole 745 mile fault that was affected, notably in the Andaman and Nicobar islands. Three months after the initial quake, aftershocks over magnitude 5 occur every few days along the fault line.

Both Aceh province and parts of Sri Lanka have been embroiled in civil wars that have slowed the flow of information and may hinder the distribution of government aid in contested or rebel held areas. Aceh has been under military control with very little access for foreigners. An independece movement has been fighting the Indonesian government for several years. Portions of Sri Lanka that were hard hit are under the control of Tamil rebels, in a war that has lasted for many years.

The scope of the disaster made it difficult to even bury the dead. Most have been buried in mass graves, although efforts were made to photograph the dead with photos and in places take DNA samples. It is hoped that these will help relatives identify victims. The World Health Organization has warned of danger of disease outbreaks that could kill thousands more. They say that dead bodies do not pose a threat, although they are unpleasant, but contaminated water supplies do. There have already been reports of outbreaks of diarhea, but the main danger is in the next few weeks. Water supplies within the affected areas have all been contaminated. Sanitation was already precarious in some of these areas. Now they have nothing. Clean water is high on the priority list for aid. Hundreds of millions of dollars of aid have been pledged from many countries around the world. Naval vessels are on the way to help but took several days to arrive. Because of the huge area involved and the limited communications available, it took days to even get reports from many areas, especially in Indonesia.

This explanation of the quake from the BBC:
How the Quake unfolded (BBC 12/27/04)

According to the USGS "The devastating megathrust earthquake of December 26th, 2004 occurred on the interface of the India and Burma plates and was caused by the release of stresses that develop as the India plate subducts beneath the overriding Burma plate. The India plate begins its descent into the mantle at the Sunda trench which lies to the west of the earthquake's epicenter. The trench is the surface expression of the plate interface between the Australia and India plates, situated to the southwest of the trench, and the Burma and Sunda plates, situated to the northeast." The interactions of these plates, along with the Indian Plate, the Pacific Plate and the Phillipines Plate, make this one of the most seismiscally and volcanically active regions of the world. Subduction earthquakes are the largest known. The 1964 Alaskan quake and the 9.5 Magnitude Chilean quake of 1960 were both subduction quakes.

In this case the subducting plate is being forced down into the earth under an overriding plate. Heat rising as the plate hits the earth's mantle and melts rises to form a volcanic island chain - Indonesia. Since the descending plate is fairly rigid and flat, when the magma rises, it creates an arc of volcanic islands on the curved surface of the Earth, which shows the direction of the plate movement nicely. The Aleutian Islands are another nice example of this process.

(See the Plate Tectonics page for more information on these processes.)

A tsumani, or tidal wave, occurs when an earthquake displaces a portion of the seafloor. In this case, according to USA Today, a section of seafloor 745 miles long was raised 100 feet by the quake. This sudden movement displaced a massive amount of water, which fanned out from the epicenter. This wave moved at 500 miles an hour across the Bay of Bengal, the Indian Ocean and the Pacific Ocean. If you look at a map of the region you will see that the areas hardest hit were across the Bay of Bengal from the epicenter at the Western edge of Indonesia.

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12/26/2003 Iranian Earthquake

Updated 1/7/2004

The 6.7 Magnitude earthquake struck at 01:58 GMT 12/26/03. This was 05:28 am local time. The epicenter was in Bam, a city of 80,000, with 200,000 in the surrounding area, in southern Iran, 620 miles southeast of Teheran. The BBC reported within hours of the quake, "A huge relief operation involving ordinary Iranians, the army, Islamic volunteer groups and local rescue teams is under way." The death toll has been estimated at over 30,000 people with over 30,000 injured. Two hospitals collapsed in the quake and remaining ones were strained to help the thousands injured. Electricity and telephone service were knocked out. Over 70% of the houses in Bam are reported to be destroyed.

The quake had been preceeded the night before by a foreshock strong enough to cause some people to sleep out of doors. Undoubtably some lives were saved as people were not inside when houses collapsed. People have continued to sleep outside due to the many aftershocks, which are typical after a major quake.

Relief efforts appear to have been well coordinated at the local level. Teams of people were working to dig out survivors soon after the quake. The dead were quickly buried in mass graves. Health and religious authorities both insisted on quick but respectful burials. Although the huge numbers of dead strained resources, this was accomplished. Trenches were dug with backhoes, groups of about 50 bodies were laid in them and covered with dirt by bulldozers. Then a new trench was started and the process repeated over and over again.

International aid arrived quickly to help survivors and help with reconstrution. Visa requirements were waived for aid workers and for the first time since the revolution 25 years ago, Americans were welcomed into Iran. There is some hope that this could be an opportunity to improve relations between the two countries.

Also destroyed was the Citadel,Arg-e-Bam, mostly dating from the Safavid period in the 16th and 17th C. This was a major historic structure, parts of which date back 2,000 years. As the largest mud brick structure in the world, and a major historic site, it was on the Unesco's list of World Heritage Sites. Bam is on major trade routes to India and the far east, as well as being an oasis in the desert has given it a special importance. The Citadel was a major tourist attraction, the loss of which will be devastating to the nation's cultural heritage and the local economy. Authorities say that it will be reconstructed, but that, of course, is far from the same as having the original.

International aid is on the way, with teams from Russia, Turkey and many other nations. Turkey has been especially responsive with aid teams, following devastating earthquakes in 1999, which raised their awareness of the need for quick aid following large quakes.

Despite frequent large quakes, Iran does not have strong building codes and many houses are built out of mud bricks and unreinforced masonry, which do not stand up well to earthquakes. Mud brick crumbles into a heavy powder without air pockets. Heavy cement roofs collapsed into houses crushing the occupants. Consequently, casualties and damage is much higher than in a similar quake elsewhere in the world. For example, the Northridge quake in Los Angeles in 1994 was a little stronger than this one but only killed about 100 people. In Kobe Japan in 1995 a similar quake killed about 5,000. There too, heavy tile roofs collapsed into many houses. Other factors contribute to the severity of a quake, but earthquake resistant buildings can make a huge different in the number of injuries.

Here is the USGS preliminary report on the causes of the quake:

This earthquake occurred as the result of stresses generated by the motion of the Arabian plate northward against the Eurasian plate at a rate of approximately 3 cm/yr (about one inch per year). Deformation of the Earth's crust in response to the plate motion takes place in a broad zone that spans the entire width of Iran and extends into Turkmenistan. Earthquakes occur as the result of both reverse faulting and strike-slip faulting within the zone of deformation. Preliminary analysis of the pattern of seismic-wave radiation from the December 26 earthquake is consistent with the earthquake having been caused by right-lateral strike-slip motion on a north-south oriented fault. The earthquake occurred in a region within which major north-south, right-lateral, strike-slip faults had been previously mapped, and the epicenter lies near the previously mapped, north-south oriented, Bam fault. However, field investigations will be necessary to determine if the earthquake occurred on the Bam fault or on another, possibly not yet mapped, fault. The December 26 earthquake is 100 km south of the destructive earthquakes of June 11, 1981 (magnitude 6.6, approximately 3,000 deaths) and July 28, 1981 (magnitude 7.3, approximately 1,500 deaths). These earthquakes were caused by a combination of reverse-motion and strike-slip motion on the north-south oriented Gowk fault.

(See the Plate Tectonics page for more information on these processes.)

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