Can a colossal earthquake in Turkey's industrial heartland hold lessons for posh California? A team of American scientists and California engineers who traveled to the quake region this week say yes.
They say the San Andreas fault in California and the North Anatolian fault, which produced the 7.4 magnitude earthquake centered near Izmit, are kissing cousins. The two faults are the same size and length, and, more importantly, move in the same way because they are caused by the same type of tectonic plate formations. They are also lethal. Both fault lines run through large cities and heavy industrial areas.
Both faults are 600 miles long, 10 miles deep and move about an eighth of an inch each year. When a segment of the fault breaks, neighboring segments can become more or less strained depending on many factors that scientists are gradually learning to measure: local fault geometry, the direction of slip, amounts of friction, and depth of motion. Scientists say each earthquake sets off a reaction that leads to the next.
On Aug. 17, the Anatolian fault ruptured for at least 60 miles east of Izmit. In some places, scientists believe, one side of the fault zone shifted more than 12 feet relative to the other side. Apparently, two fault segments may have broken 30 seconds apart, producing such large and sustained shocks.
The American scientists, working under a $1 million grant to bring back some lessons from the latest quake, will also take a hard look at Turkey's structural damage. Building codes in California and Turkey are similar, but seriously underapplied in Turkey's quake zone.
The damage in Turkey has led to calls for criminal charges against faulty contractors. It also opened a socioeconomic divide between more well-to-do Turks who are Muslim in name only, and often less wealthy Muslim adherents (Turkey is officially over 95 percent Muslim), who are mostly seen as superstitious. The affluent are more likely to think of litigation, while the poor stress the will of Allah.