Lessons from Christchurch

This piece was originally posted on February 24, 2011. Since then, there have been approximately 9,000 aftershocks in the Christchurch, New Zealand area.

The “Ring of Fire” earthquake zone is the source of 80% of the world’s earthquakes.

According to the USGS, the Ring of Fire “extends from Chile, northward along the South American coast through Central America, Mexico, the West Coast of the United States, and the southern part of Alaska, through the Aleutian Islands to Japan, the Philippine Islands, New Guinea, the island groups of the Southwest Pacific, and to New Zealand”.

This earthquake belt was responsible for 70,000 deaths in Peru in May 1970, and 65 deaths and a billion dollars’ damage in California in February 1971 (the San Fernando quake).

Located on the Ring of Fire, Christchurch, New Zealand has some of the world’s most stringent building codes. Why then, did Tuesday’s 6.3 magnitude earthquake cause the collapse of many buildings, when September’s 7.1 magnitude quake in the same vicinity did little damage?

The devastation from the latest quake was an unfortunate combination of proximity, timing, and stress from September’s stronger but more distant rupture.

Tuesday’s earthquake, centered just 3 miles from Christchurch, a city of 390,000 people, was also just 3 miles deep. Shallower, closer quakes are more destructive. While September’s quake struck early on a weekend morning, catching most people at home in bed, Tuesday’s quake struck in the middle of a workday, finding people at multistory pre-World War II as well as more modern buildings, many of them unreinforced masonry, already weakened by September’s temblor.

The New Zealand Herald newspaper gives us a real-time glimpse into actual conditions following the quake. This report is from 4:22 PM today:

- All hospitals are operational and have been emptied to make room for victims

- 80% of the city is still without water. Emergency water supplies are available at locations, primarily schools throughout the city and neighboring towns. People are advised to bring their own containers. The water needs to be boiled before drinking.

If it rains, residents are urged to save all water for drinking. It is not to be used to flush toilets, take showers or baths.

- The sewage system has been damaged. People are advised not to flush their toilets and to use a bucket or dig a hole outside for human waste.

- Gasoline supplies are low and needed for emergency vehicles. People are advised not to buy gas except for critical uses. Roads are damaged.

- People are encouraged to walk to keep vehicles off the road. The public is to bring bedding, medications and personal effects with them to shelters.

- Power has been restored to 60% of the city. It may be several weeks before it is restored completely.

- All schools and day care centers are closed. People are only to report to work if they work in an industry supplying food.

- Telephone and cellphone calls are to be limited. Text messages are preferred as they place less load on networks. In yesterday’s paper, people were asked to change their cellphone messages to let callers know their location and to give alternate details if possible.

- Many supermarkets and ATMs are closed due to damage.

- The Port has sustained serious damage

- Aftershocks are continuing. More damage is expected. Residents are urged to drop, cover and hold on at the first sign of an aftershock.

Update: 2 26 11

The death toll stands at 145, with hundreds more missing. There are many traumatic injuries from collapsed concrete buildings.