Earthquakes Not Growing, Just Populations

Experts say the earthquakes that shook Haiti, then Chile and Turkey are not a problem of what is happening under the ground, but above it.

Scientists say that more people are moving into megacities that happen to be built on fault lines, and they are building substandard structures that cannot withstand earthquakes.

Better seismic monitoring and around-the-clock news coverage has made it seem that earthquakes are increasing.

"I can definitely tell you that the world is not coming to an end," Bob Holdsworth told the ASsociated Press (AP), referring to the number of quakes. Holdsworth is an expert in tectonics at Durham University in northern England.

Over 200,000 people were killed in Haiti last month by a 7.0 magnitude earthquake.  Less than two weeks ago an 8.8 magnitude quake took the lives of 900 people in Chile.  And on Monday, Turkey was hit with a 6.0 magnitude quake that killed at least 51 people.

According to the U.S. Geological Survey, there are 134 earthquakes a year that have a magnitude between a 6.0 and a 6.9. 

Paul Earle, a seismologist at the U.S. Geological Survey, told AP the reason for so many earthquakes this year is because the 8.8 quake in Chile generated a large number of strong aftershocks. 

Earle said that it is not the number of quakes that occur, but their devastating impacts that gain attention with the death tolls, mostly because of construction standards and crowding.

"The standard mantra is earthquakes don’t kill people, buildings do," he said.

University of Colorado geologist Roger Bilham said there have been more deaths over the past decade from earthquakes.  Bilham wrote in an opinion column last month in the journal Nature that there should be better construction standards in the world’s megacities.  Last year he revealed a study on earthquake deaths, population, quake size and other factors that produced disturbing results. 

"We found four times as many deaths in the last 10 years than in the previous 10 years," Bilham told AP on Monday. "That’s definitely up and scary."

Other experts have said that they also noticed a general increase in earthquake deaths.  The World Health Organization said there have been 453,000 deaths from earthquakes in the last decade. 

However, Statisticians say the hit-or-miss nature of earthquake fatalities makes it hard to find a trend in deaths.

Two statistic experts found no statistically significant upward trend since the 1970s because of variability. 

University of Miami geologist Tim Dixon told AP the Haiti quake set a modern record for deaths per magnitude of earthquake "solely as a function of too many people crammed into a city that wasn’t meant to have that many people and have an earthquake."

Disaster experts say they have seen more deaths from earthquakes that would not have been as bad decades ago.  They pointed out two specifically – a 1999 earthquake in Izmit that killed 18,000 people and the 2001 disaster that killed 20,000 in Bhuj.

"Look at some of the big ones recently," said Debarati Guha-Sapir, director of the WHO’s disaster epidemiology research center. "Had the Izmit or Bhuj quakes happened 30 years ago, the events would have been relatively insignificant as the population of these cities were a third of what it was when it did happen. Increasing population density makes a small event into a big one."

Bilham told AP that of the 130 cities with over a million people globally, more than half are on fault lines, making them more prone to earthquakes.

"I’ve calculated more than 400 million people at risk just from those," he said.

Bilham said that developing nations, where the population is booming, do not pay attention to earthquake preparedness.  "If you have a problem feeding yourself, you’re not really going to worry about earthquakes."

He said that when he took a trip to Haiti after the January quake, people were rebuilding their houses their old unsafe ways, instead of quake-proof methods.

Dennis Mileti, a former seismic safety commissioner for the state of California, said that the attention from the earthquakes in Haiti and Chile would not last.

"People are paying attention to the violent planet we’ve always lived in," Mileti said. "Come back in another six months if there has been no earthquakes, most people will have forgotten it again."

Image Courtesy Marco Dormino/United Nations