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★“Liquefaction” Key to Much of structures to shift or sink or
Japanese Earthquake Damage collapse .
The massive subduction zone1 But most earthquakes are much
earthquake in Japan caused a shorter than the recent event in
significant level of soil Japan, Ashford said. The length of
"liquefaction"2 that has surprised the Japanese earthquake, as much as
researchers with its widespread five minutes, may force researchers
severity, a new analysis shows. to reconsider the extent of
"We've seen localized3 liquefaction damage possibly
examples of soil liquefaction as occurring in situations such as this8.
extreme as this before, but the "With such a long-lasting
distance and extent of damage in earthquake, we saw how
Japan were unusually severe," said structures that might have been okay
Scott Ashford, a professor of after 30 seconds just continued to
geotechnical engineering4 at Oregon sink and tilt as the shaking continued
State University5. "Entire structures for several more minutes," he said.
were tilted and sinking into the "And it was clear that younger
sediments," Ashford said. "The shifts sediments, and especially areas built
in soil destroyed water, drain and gas on recently filled ground, are much
pipelines6, crippling the utilities and more vulnerable."
infrastructure munities The data provided by analyzing
need to function . We s