Excellent South Asia Earthquake Resource
October 14th, 2005Posted by: Roger Pielke, Jr.
And now, back to your regularly scheduled programming … A colleague of mine here at CIRES, geologist Roger Billham, has an excellent web site on the South Asia earthquake. Roger observes,
“How bad was it? If reports from the Kashmir epicentral region are confirmed, the number of fatalities exceeds 40,000 making it the most fatal earthquake ever to occur in the Indian subcontinent. The number of fatalities in an earthquake is linked to the vulnerability of local buildings, population density, and shaking intensity. In 1935 a Richter magnitude M7.5 strike-slip earthquake near the city of Quetta, the only large settlement in an otherwise sparsely populated region of Afghanistan, Pakistan and Baluchistan, resulted in an estimated 35,000 dead. The M7.8 Kangra earthquake in 1905 caused 20,000 fatalities, and the Mw=7.6 Bhuj 2001 earthquake 18,500.”
This figure which shows deaths versus earthquake magnitude is very interesting. Of it Roger notes,
“Deaths vs earthquake magnitude for earthquakes throughout the world 1900-2004 compared to the Kashmir 2005 earthquake. Although a simple relation between earthquake magnitude and the number of resulting deaths can be discerned (gray shading), the fatal consequences of large earthquakes depends more on their proximity to urban populations, the vulnerability of dwellings, and the time of day, than on the energy released. (fig. from Hough & Bilham,2005). The Sumatra/Andaman/Nicobar earthquake resulted in epicentral building collapse and damage, and huge loss of life along a thin but concentrated population on a coastal strip throughout the Indian ocean and Andaman sea.”
Lots more here.
October 14th, 2005 at 7:18 am
Regarding the figure of fatalites vs. magnitude, I’d be keen to know what proportion of the variability in fatalities can be explained by the different factors – “proximity to urban populations, the vulnerability of dwellings, and the time of day” – as well as magnitude.
October 14th, 2005 at 8:23 am
Daniel- Good question. I’ll ask Roger, though he is out of the country for a month, so it will be a while before we hear back.
October 14th, 2005 at 10:08 am
Thanks to Roger Billham for this speedy reply from the Adaman Islands:
“The collapse of buildings in Kashmir is widespread, and it looks to me as many of them collapsed because of poor construction
The population is quite sparse, spread over numerous valleys- no high rise buildings etc
The time of day matters in that if farmers are in fields they are usually immune to shaking. In this case the schools collapsed – this is indefensible! Pakistan spends 60% of her budget on defense. Yet 6% on strengthening housing would have save most of the lives in this earthtquake”
October 15th, 2005 at 3:18 pm
Judging from the web site and historical article, it looks like the Kathmandu Valley is a major disaster zone waiting to happen. Seems to be the largest population (2 million +) directly in an area overdue for a great one. Nothing is built to survive, the government is already essentially non-functional, and there is no money to spare. This recent quake killed around 40K and it’s a relatively unpopulated region with functional governments. Has there been an analysis of Nepal’s vulnerability?