Earthquakes and Myths
"Myths are stories told by people about people: where they come from, how they handle major disasters, how they cope with what they must and how everything will end.” – Robert O’Connell
I frequently encounter otherwise rational, intelligent people repeating earthquake-related myths they’ve heard, especially in the wake of large, destructive quakes such as the M 7.0 Haiti event on January 12th – the worst natural disaster to strike Haiti in more than 200 years. So here’s a teachable moment – a time when we can debunk at least some of the myths that are often accepted as true, but lack factual basis. Here are three:
The magnitude of an earthquake determines whether disaster assistance is forthcoming. A magnitude 7 quake in the middle of a sparsely populated desert will do far less damage than a magnitude 6 in a densely populated region. It’s the magnitude of the damage, not necessarily the magnitude of the earthquake itself, that determines the level of response. However, if you live in an earthquake-prone region, remember that it could take up to a week before aid reaches you; in some remote places, even longer. Port au Prince and its surrounding towns and villages were on their own for the first few days, and those without access to water, food and medical care numbered in the tens of thousands.
We have good building codes, so we must have good buildings. This is partly true for countries or regions with buildings constructed under modern building codes. But even in countries with strict codes, enforcement of those codes can be an issue. And in the case of older buildings, retrofitting (bringing the building up to modern standards) is at the discretion of the building’s owner. Large segments of urban populations living I developing countries – Haiti for example – are at higher risk because building codes are either nonexistent, not enforced, or the buildings are so old they are vulnerable to ground motion. Pierre Fouche, Haiti’s only earthquake engineer, stated recently that Haiti has no building codes, and most of the country’s buildings “were barely built to engineering standards and were hopelessly fragile in the grip of such a strong quake”. Tens of thousands of people in Port au Prince were crushed by buildings that collapsed, and untold numbers more remain trapped under the rubble. Most buildings in the city are made of masonry – bricks or construction blocks – which tend to perform badly in an earthquake. Ironically, in 1751 and again in 1770, two major earthquakes destroyed Port au Prince. As a result of these earthquakes and several minor ones in between, the authorities required building with wood and forbade building with masonry.
Earthquakes are becoming more frequent. This one may fall under the heading of “the end of the world is coming soon”. However, research shows that earthquakes of magnitude 7.0 or greater have remained fairly constant over the last hundred years -- and have actually decreased in recent years. On the other hand, there are more seismological centers and instruments capable of locating many small earthquakes that went undetected in earlier years, so it may seem like there are more.
There's nothing I can do about earthquakes, so why worry about them? Earthquakes can't be stopped, but you can prepare. Put together earthquake kit and make sure to keep a portable kit in the family car as well (non-perishable food, water, blankets, flashlights, etc.), practice "drop, cover and hold" drills at home with your family and at work, and develop an earthquake plan (where would you meet family members if you weren't together when an earthquake hit?). And, if you live in a high-probability earthquake area, think about earthquake insurance.
- State of California Dept. of Conservation
- Evolutions of Myths, Robert O’Connell
- NPR News – Haiti’s Buildings Weren’t Fit to Withstand Quakes
- BBC News - Haiti devastation exposes shoddy construction
- San Francisco Chronicle Quake Country – How to Make an Earthquake Kit
- MSN Money – Get the Facts on Earthquake Insurance
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John Rundle is a Distinguished Professor of Physics and Geology at UC Davis and the Executive Director of the APEC Collaboration for Earthquake Simulations. He chaired the Board of Advisors for the Southern California Earthquake Center from 1994 to 1996. Read John's blog.