It was thought that the basin would amplify shaking from a large earthquake. Scientists hunting for signs of liquefied soils that could potentially cause buildings to collapse or pipes within them to break have found surprises as well. Researchers had been particularly concerned that some places filled with loose sediments, like those around Kent, would experience large-scale liquefying of soils in a major earthquake. Yet today, scientists just in from surveying such regions said soils from many of them were largely sitting perfectly, solidly intact. Like others, Kathy Troost, a research geologist at the University of Washington, was intrigued and, at this early stage, puzzled.
Scientists searching for signs of liquefied soils look for so-called sand volcanoes.
These are created when underlying soils liquefy and the pressure of overlying soils forces the mixture of water and sand and debris upward, creating a fountain that leaves behind a sand volcano. Even the site of the origin of the quake which occurred in nearly the same spot as a similar-sized earthquake in 1949 has geologists taking a second look at the Puget Sound region and wondering if there is something special about this previously undistinguished spot that has shaken the region hard twice in just over 50 years. But while in general the surprises have been in the direction of less damage and shaking than more, scientists emphasized that residents should not view the new findings as a sign that the Puget Sound region is safer than it had appeared to be. While they say they do not expect surprises, they are continuing to search for damage and note that there are still risks from this most recent earthquake. The biggest landslide occurred three days after the earthquake.