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| KoKo | Posted
on 23-Aug-01 03:41 PM
WRITING IN Friday’s issue of the journal Science, geophysicists Roger Bilham and Peter Molnar of the University of Colorado and Vinod Gaur of the Indian Institute for Astrophysics in Bangalore analyzed geological evidence and examined historical records regarding earthquakes in the region. “Our message is that a careful evaluation of all the data indicates that large earthquakes are overdue, and that earthquake-resistant design should be taken very seriously indeed,” Bilham said in an interview. SUDDEN LURCHES The Indian subcontinent once was an island continent that 40 million years ago crashed into the rest of Asia, pushing up the Himalayan mountains. The subcontinent’s basement rock still flexes and slides underneath the Himalayan mountains, not steadily but in localized sudden lurches during large earthquakes, the researchers said. Satellite measurements show that most of the force created by tectonic plates pressing against each other is absorbed in a relatively small area between India and southern Tibet, they added. Earthquakes represent the main release valve for this accumulated convergence pressure, they said. While historical records are spotty, Bilham said there appear to have been fewer great earthquakes in the Himalayan region than one would expect in the past 300 years, suggesting that the continuously building pressures could trigger huge quakes at one of several locations along the fault line. “What we’ve done is to examine the recent data to see whether we can offer any certainty about these future events,” Bilham said. “And what surprised us is the large area that appears not to have experienced a great earthquake for 200 years, maybe 300 or even more, and the size of the events that could possibly occur as a result.” A University of Colorado graphic shows how the movement of tectonic plates creates uplifts in the Himalayas. CAPITAL CITIES IMPERILED The concentration of many millions of people in large cities makes the potential human toll almost unimaginable, Bilham said. Major earthquakes in the Himalayan region could place at risk the capital cities of Bangladesh, Bhutan, India, Nepal and Pakistan, as well as numerous other large cities. The urban population in the Ganges Plain has increased by a factor of 10 over the past century. About 50 million people live in areas that are at high risk for a great Himalayan earthquake, the researchers estimated. Any single earthquake could affect up to 10 million people. India’s population has doubled to around 1 billion people since the last great Himalayan earthquake in 1950 in Assam, which had a magnitude of 8.5 and was the strongest earthquake ever recorded that did not take place on the ocean floor. A great earthquake in the Himalayan region could produce more fatalities even than the earthquake that hit the city of Tangshan in northeastern China in 1976, Bilham said. The official death toll from that 7.8-magnitude earthquake was 240,000 people. The researchers said they foresee the possibility of earthquakes in the magnitude range of 8.1 to 8.3 in the Himalayan region. The century's worst quakes This list shows earthquakes that caused a terrible loss of life in the 20th century | 1 | 2 | 3 | 4 Deaths Magnitude Country Year 240,000 7.8 to 8.2 Tangshan, China 1976 200,000 8.3 Xining, China 1927 150,000(est) 8.6 Gansu, China 1920 143,000 8.3 Yokohama, Japan 1923 70,000 7.7 Northern Peru 1970 50,000 7.3 to 7.7 Northwest Iran 1990 33,000 7.9 Erzincan province, Turkey 1939 28,000 8.3 Chillan, Chile 1939 | 1 | 2 | 3 | 4 Deaths Magnitude Country Year 25,000 6.9 Turkish-USSR border 1988 25,000 7.7 Northeast Iran 1978 22,778 7.5 Guatemala 1976 20,000 8.6 Santiago/Valparaiso, Chile 1906 19,000 8.6 Kangra, India 1905 15,613 7.8 Turkey 1999 12,000 8.1 Central Asia 1907 10,700 8.4 India/Nepal 1934 | 1 | 2 | 3 | 4 Deaths Magnitude Country Year 9,500 8.1 Michoacan, Mexico 1985 6,000+ 7.2 Kobe, Japan 1995 45,000 9.5 Chile 1960 5,000 6.1 Northeast Afghanistan 1998 2,990 8.9 Sanriku, Japan 1933 2,500 7.1 Varto, Turkey 1966 2,300 6.7 Turkey 1975 2,000+ 6.8 Taiwan 1999 | 1 | 2 | 3 | 4 Deaths Magnitude Country Year 1,530 8.7 India/Assam/Tibet 1950 1,500 7.1 Northern Iran 1997 1,330 8.4 Tonankai, Japan 1946 1,300 6.9 Turkey 1983 1,300 6.0 Turkey 1946 1,171 6 Western Colombia 1999 1,100 7.3 Gediz, Turkey 1970 1,000 8.9 Colombia 1906 Source: Associated Press, Reuters, MSNBC research Printable version CONSTRUCTION PRACTICES Advertisement Bilham said it appears that changes in construction practices intended to make buildings more resistant to earthquake damage have not reduced the percentage of the population killed in a major quake. For example, he said the 19,000 confirmed deaths in the earthquake in Bhuj, India, this past Jan. 26 — an earthquake not in the Himalayan region — represented about the same proportion of deaths as seen in an 1819 temblor in Kachchh, India. Major earthquakes in urban settings in recent years have inflicted death tolls of about 1 to 10 percent of the population — and may have approached 30 percent in Tangshan, according to experts. A 10 percent death rate in a city of 5 million would mean 500,000 people dead. © 2001 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content is expressly prohibited without the prior written consent of Reuters. |
| Hallaunu | Posted
on 24-Aug-01 10:55 AM
I hope Nepal has a contingency plan in case there is a big quake. I dont know if the emergency vehicles, rescue workers, hospitals are enough to handle what is likely to be a great disaster in the event of an earthquake. There has not been a really big quake in Kathmandu for 60 years. |
| nepali | Posted
on 24-Aug-01 02:39 PM
koko u suck man, stop posting these news. dont u have a brain to discuss something. nepali |
| Jarne | Posted
on 24-Aug-01 09:04 PM
Koko, this is an important issue you have brought for discussion. As usual, no one is listening. They will be surprised as they always are when something of this nature happens. Nepal never plan, it just lets this happen. Look at the unplanned expansion of neighborhoods. The is no long range Planning in Nepal. Sadly, many will be killed and injured. I just hope someone will pay attention to the warnings. I saw this story on CNN this morning. The warnings include Afghanistan, Pakistan, Tibet Nepal, India, and Bangladesh. |
| details | Posted
on 25-Aug-01 12:01 AM
more details at http://cires.colorado.edu/~bilham/Nepal.html |