Earthquake in Seoul

Two days ago there was an earthquake here in Seoul. A magnitude 3.0 shake occurred with its epicenter located near western Seoul on Tuesday evening. No injuries or serious property damage were reported.

The question is, how Seoul, a city of 20 million residents living in skyscrapers, is resistant to such a hazard?

Natural hazards cause loss of more than $700 million in property every year, mostly due to flooding and landslides during monsoon season. Occasionally tsunami or drought hits the peninsula adding more costs and loss to recover.

As to the risk of earthquakes, Korea is not based directly at the Pacific Hot Ring, but close enough to be called a semiseismic territory with small but present danger of an earthquake bigger than 6 Richter scale degrees.

Pacific tectonic plate meets with Eurasian one in the subduction zone through Japan and Philippines. From the west though, occasional wave of shakes may occur because of constant movement of Indian plate to the north.

Oldest chronicles note such phenomena in Korea. In 779 AD the quake killed 100 people and destroyed number of houses in Gyeongju, capital of Silla. During the Japanese occupation regular earthquake observation system was established and noted more than 320 cases of moderate magnitude.

In 1978 an earthquake of 5.0 destroyed 1128 buildings in one of the smaller cities in Korea, no casualties were reported luckily.

Before that, only public facilities, such as power plants and tunnels had any quake- resistant design. After 1978 every building taller than 6 levels has to be earthquake - resistant based on the average risk which is magnitude of 7.

If it comes to houses and apartments, this is the most vulnerable issue. Before 1988 citizens did not matter much in South Korea, or at least not their private belongings such as places to live. There was also no middle class, as middle range salary sector emerged with establishing of democracy in 1988. Since then, more attention and civil control is put to the Civil Defence.

After 1995 when severe earthquake stroke Kobe in Japan central government established special research institute which aim is to map and address the risk of quakes.

There are also a lot of agencies and offices which address the issue in terms of reaction, response and loss restoration, like Safety Management Bureau, National Safety Management Information System, National Disaster Management System, but their major problem is lack of sufficient communication systems and being understaffed ( as stated in: http://emi.pdc.org/cities/CP-Seoul-July2006.pdf).

What would be sites fragile to the quake? Squatters in some parts of the city, where rural migrants still live, as well some poor quarters of Bongcheon-dong, some sites of north Seoul, old buildings in Yongno.

What to do in case of a quake:
- don't panic
- avoid elevators
- cut off gas and electricity
- evacuate if possible

BTW. And the quake of 3.0 or similar you may as well sleep through as I did :P