Tragic alarm on earthquake codes

By

The toll taken by the earthquake that hit Turkey this week is a tragic reminder that disaster preparedness depends on the thoroughness of thousands of local contractors and officials - not just on the knowledge of a few scientists in a lab.

Turkey is one of the most seismically active areas of the world, similar in that respect to California or Japan. Its national government has drawn up earthquake-protection building codes that are as tough and realistic as any in the industrial world.

But implementation and oversight of these codes are left to provinces and local communities, says Nafi Toksz, a geophysics professor at the Massachusetts Institute of Technology in Cambridge. "Enforcement is uneven," he says. "Expertise and a realization of their significance" are often lacking at the grass-roots level.

Recommended: Could you pass a US citizenship test?

In the wake of the disaster, sentiment in Turkey is running high against the laxity and corruption that many Turks feel compounded the damage from the temblor.

"Murderers" is the bold front-page banner headline that the mass-circulation daily Hurriyet used Wednesday to describe the people it considers responsible for the quake devastation.

Some Turkish experts estimate that more than half of the buildings in Istanbul do not comply with the requirements and standards set by the laws. That, they say, is why several tall apartment buildings on the outskirts of the city fell like a pile of cards, while older construction - even ancient Byzantine walls and minarets - survived.

Prime Minister Bulent Ecevit has complained about this situation as well as the fact that Turkey lacks the organization needed for speedy action after such disasters, from well-trained rescue teams to communication systems.

Help from abroad

Substantial foreign assistance, from the US, Israel, Russia, and even longtime adversary Greece, has already started to arrive.

Such aid will help the nation recover from the shock and grief of a disaster in which the death toll is more than 3,500. The question is whether the national government will now finally force longer-term measures to prevent the scale of destruction wrought by Tuesday's temblor, say Turkish analysts.

Mr. Ecevit has pushed through parliament some major economic and social reforms that have been on the Turkish agenda for a long time.

"Our hope is that, after this terrible experience, Ecevit will give priority to this problem and show the guts to enforce measures that we remember only at times of disaster like this," says a Turkish academic. "That's not an easy job, but it is as important as dealing with the problem of terrorism."

The earthquake, by almost any measure, was a huge one. US scientists made a preliminary estimate that it was 7.8 on the Richter scale. Turkish measurements registered a magnitude of 7.4.

The most recent big US temblor was the Northridge earthquake in Los Angeles on Jan. 17, 1994, which registered 6.8 on the Richter scale. If the larger US measurement on the Turkey quake is not revised downward, it "means that the ground movement at the epicenter was approximately 10 times as great" as Northridge, notes Don Blakeman, a geophysicist at the US Geological Survey's National Earthquake Information Center in Golden, Colo.

In terms of susceptibility, Turkey's geology is similar to southern California. Where Los Angeles sits astride the San Andreas fault, Turkey is atop the North Anatolian fault, a fissure that forms the boundary between two crustal plates.

The North Anatolian fault stretches 744 miles from just inland of Turkey's northern coast to its terminus at the Adriatic Sea. Over the past 60 years, it has been responsible for seven major quakes, each rating 7 or higher on the Richter scale, each affecting a portion of the nation just west of the preceding rupture zone.

Ironically, the quake struck just as the Turkish government began installing a network of high-tech sensors to measure strain along the fault.

Two months ago, Turkish seismologists installed the first of 11 receivers that use signals from the US global positioning satellite system to pinpoint their locations. As strain builds and the crust slowly deforms, the receivers move in relation to each other. Tracking those movements tells seismologists where strain is growing and which fault segment is likely to break.

The $1.6 million program - a joint effort between MIT and Turkish universities and government agencies - was adopted in 1997 following nearly a decade of measurements using other means that showed strain building along the segment that ruptured on Tuesday. But while researchers could say strain was building, they couldn't say when the fault was likely to snap.

Preparing for the next one

Professor Toksz of MIT says he remains concerned about the next segment along the North Anatolian fault. It passes by Istanbul, a city of 12 million people and home to some of the world's most treasured historic buildings. As tragic as Tuesday's quake was, he says, a similar quake on the next segment could be far worse.

Even technology that relies on GPS satellites originally designed for the US military can't predict when and where earthquakes will strike, however. What it can do, says Mr. Blakeman of the US Geological Survey, is direct relief groups to the site of a damaging earthquake more rapidly. "We can tell them where to go and how bad the earthquake may be," he says.

Damage is dependent not just on the size of the temblor, but on where it strikes. Densely populated areas, not surprisingly, are more vulnerable to quakes. Each time there's a large earthquake with a series of aftershocks, geologists are better able to define the locations of dangerous faults, and judge how active they are.

"But remember that each of these quakes is just one more data point in a whole series. It takes a lot of time, a lot of work, to put the whole puzzle together," says Blakeman.

Turkey is not the only country where illegal, flimsy construction has been exposed. The same complaint arose following deadly quakes in Latin America, China, and Central Asia.

"We known how to build earthquake-resistant structures, and the rules and regulations are in place in most countries, including Turkey," says Andrei Reinhorn, a civil engineer at the State University of New York at Buffalo. "But society needs to accept that these rules are costly and make sure they're enforced."

(c) Copyright 1999. The Christian Science Publishing Society

Share this story:

We want to hear, did we miss an angle we should have covered? Should we come back to this topic? Or just give us a rating for this story. We want to hear from you.

Loading...

Loading...

Loading...