Don't blame sneaky Greeks in a hollow horse for breaching ancient Troy's defenses. Don't look to besieging armies to explain Jericho's repeated destruction. Don't ask who buried some of the Dead Sea scrolls. Impersonal earthquakes - not human violence - may have done the job.
Geophysicist Amos Nur has taken a new look at ancient Eastern Mediterranean history. Where archaeologists see mainly the remains of warfare and pillage, he sees seismic destruction. He has also taken a new look at the region's seismicity.
According to conventional theory, quakes occur independently here and there along a fault line as accumulated strain is released in local areas. Instead, Dr. Nur sees evidence that devastating quakes can occur in swarms that can unzip an entire fault line. Swarms would be separated by long periods of quiescence. This could lull inhabitants into a false sense of security. But when a swarm hits, cities built along the fault could be knocked out within decades. Nur says that may be what ended the region's Bronze Age when dozens of civilized centers - including Knossos, Mycenae, and Troy - were destroyed within a 50-year period. If it happened then, it could happen now. That makes this new look at ancient history relevant to efforts to better understand earthquake hazards in regions like the Middle East, where large population centers now lie along or close to dangerous fault lines. Long-held assumptions Nur, who is chairman of Stanford University's geophysics department in Stanford, Calif., explained this to reporters last month during the meeting of the American Geophysical Union in San Francisco. He noted that, while he feels confident of his ideas, they challenge long-held assumptions. He needs more research to back them up. It can seem arbitrary, for example, to blame an earthquake for a city's destruction when there's evidence that a war was going on. In Nur's view, the quake opened up the defenses to attackers. He explained that the protected centers were strongholds of an elite that exploited the populace. "The earthquakes made these centers open to attack, mostly from the indigenous people," he said. Even in Troy, where there was a besieging army, a quake seems to Nur to have been the likely agent in opening the city walls. …