Earthquake alert: Who's ready to cope?
As Colombia digs out, a new worldwide network emerges to help nationslimit the toll of temblors.
To Swiss-based geophysicist Domenico Giardini, one of the enduring lessons from last week's devastating earthquake in Colombia is simple in statement, but difficult in execution. "If you want to save lives," he says, "you have to build better houses."
Yet to budget for and build better houses, schools, and offices appropriate to the risk, officials need to know the size of the risk they face. In many parts of the world, particularly in less-developed countries, that information hasn't existed - until now.
Teams of researchers worldwide are unveiling the results of a six-year effort to quantify the hazard from earthquakes in key regions of the world.
The aim of the effort, known as the Global Seismic Hazard Assessment Program, is to provide basic information - and the tools to expand it - to countries around the world.
Outside of developed countries, such as the United States and Japan, preparedness levels vary widely, according to Nafi Toksoz, a professor of geophysics at the Massachusetts Institute of Technology.
"You have some countries like China, Mexico, Turkey, and Chile that are well aware of the hazards and have detailed hazard maps for designing and constructing buildings," says Dr. Toksoz, a specialist on seismic hazards in the eastern Mediterranean. "Others have made less progress. Even though they have general hazard maps, the hazards are not well-defined and building codes are not strictly enforced."
One of the more troubling trends has taken place in Russia, where a once-enviable Soviet-era network of seismic monitoring stations - used to record data that can help analyze earthquakes, locate faults, and otherwise contribute to a better understanding of earthquakes - has dwindled to a poorly funded few.
"Russia has a federally funded seismic monitoring program, created in 1993. But the government paid none of the budgeted money into the program whatsoever in 1998, and this year will probably be just as bleak," according to Gennady Sobolev, who heads the seismology department at the Russian Academy of Science's Institute of Earth physics.
He estimates the country has 30 monitoring stations working - but only sporadically, because of the country's financial crisis.
Even where hazards are known, earthquakes can defy past trends. The fault system that leveled Armenia, Colombia, Jan. 25 has been reasonably well characterized, according to Waverly Pearson of the US Geological Survey's office in Golden, Colo. Faults there typically rupture at depths of from 100 to 150 kilometers (62 to 93 miles).
At those depths for that area, he says, a magnitude 6.2 quake would do very little damage. This time, however, the fault ruptured much closer to the surface, at a depth of 17 kilometers.
A network of research labs?
Still, the reports and maps coming out of the global hazard program are expected to provide a useful starting point for many countries. Moreover, the program's leaders say they already see signs that collaborations established during the effort will continue, with some blossoming into regional seismic hazard research labs.
To countries such as the US or Japan, which have spent hundreds of millions of dollars over many years to identify faults and take detailed measurements of ground motion and strain in specific locations, some of the results slowly emerging from the global program may seem overly general. In eastern Africa, for example, where the crust is splitting apart along the Great Rift Valley, the eight African and Norwegian scientists who analyzed the hazard did so on a regional basis, not at the level of individual cities.
Yet Dr. Giardini, director of the Swiss Seismological Service and coordinator of the global assessment program, notes that for places like eastern and southern Africa, where large earthquakes occur, even regional estimates of the hazard represent a major step forward. Out of the nine countries participating in the African effort, only South Africa had any seismic-risk information at the outset - stemming from its mining activities.
"We're planting seeds in places where they've never been established before," agrees Kaye Shedlock, a geophysicist at the US Geological Survey office in Golden, Colo., and a leader of one of the regional analysis groups.
As important as the data are, however, their use - and acceptance - is critical. "There are countries that didn't want to see high hazards," she says. In one case, the country was interested in building a reservoir in the mountains as a water supply. Referring to the geological processes that build mountains and generate earthquake faults, she adds, "active tectonics makes good scenery, but those areas show up red on our maps" of seismic hazards.
Still, she and others note, population pressures virtually ensure that people and earthquake zones will mix. At that point, adequate building codes and public education play key roles in ensuring the fewest casualties and least damage during a quake. Sometimes it takes a tragic temblor to drive the point home.
In July 1976 a quake with a magnitude measuring between 7 and 8 struck the city of Tangshan, in eastern China, killing between 150,000 and 200,000 people. Since then, the government has stepped up its investment in earthquake research and established building codes to account for quakes, according to Tan Jianfeng, a spokesman for the State Seismological Bureau in Beijing. Last year, he says, the government pumped more than 300 million yuan (about $37.5 million) into earthquake research. By contrast, the US National Science Foundation is funding $29.9 million in quake-related research, and is asking for $37.6 million for the fiscal year beginning Oct. 1.
In Mexico, the Mexico City quake of 1985, which killed an estimated 10,000 people, spawned efforts to reform building codes and educate the public about how to respond during a quake.
Schools and neighborhoods began conducting periodic earthquake drills, and the government installed an early-warning system of seismographs that can give Mexico City residents up to an extra minute's warning if a big quake strikes the west coast. "We're really focusing our attention on prevention measures," says Javier Prez, director of programs for Mexico City's civil defense agency.
"Education efforts are most successful where people see something," acknowledges Giardini. "When seismicity is sparse, it's pretty difficult to get anyone's attention."
Yet even with up-to-date building codes, population pressure can push structures onto areas that would seem to defy the most canny civil engineer. The Kobe earthquake in Japan four years ago wreaked some of its worst havoc on modern buildings, built to code, that were erected on "reclaimed" land, or fill, which liquefies in a heavy quake.
Since then, the government has worked harder to enhance readiness, according to Kazunori Mochizuki, a spokesman for the earthquake division of Japan's National Land Agency.
On the other side of the Pacific, the 1994 Northridge earthquake in southern California's San Fernando Valley inflicted $26 billion in damage - largely because researchers had underestimated ground motions, which took a toll on buildings that weren't designed to take the load they actually received. Since then, codes have been strengthened to reflect the new information. Still, more should be done, some researchers say.
"It's a question of priorities and awareness," says MIT's Toksoz. "We know earthquakes are going to happen; we know buildings are going to fail.
"Given these, education and response planning have to get higher priorities."
* This article includes reports from staff writers Howard LaFranchi in Mexico City, Kevin Platt in Beijing, and Cameron W. Barr in Tokyo, as well as correspondent Fred Weir in Moscow.