The problem with the Times’s piece is the adjective “Japanese-style.” The article quotes an earthquake expert making the important observation that unlike Japan, where tectonic plates are converging, there is no subduction where plates meet in California. Instead, they slide past one another along a transform fault, and while the horizontal slip can create tsunamis, they are generally not as large as those created by thrust faults in subduction zones, which involve vertical slip and thus greater displacement of water (the article did mention that there is a subduction zone in the Pacific Northwest; an article produced by the U.S. National Science Foundation for U.S. News & World Report said the risks there are “nearly identical” to those in Japan). Another expert quoted in the article estimates that faults in Southern California could generate temblors of magnitude up to 7 to 7.5, well short of the 9.0 mega-quake that shook Japan. So, no, perhaps a “Japanese-style” quake and tsunami are not in the offing, but that statement belies the fact a “California-style” quake could cause plenty of destruction nonetheless.
Another article from Reuters, by Steve Gorman, took a similar tack as the Los Angeles Times, pointing out that the next “big one” in California is “expected to pale next to the Japan quake.” It explained that subduction zones create the world’s most powerful earthquakes and “a 9.0 quake is virtually impossible along the San Andreas” network of strike-slip faults. Unlike the Times, however, it quoted a USGS spokesperson emphasizing that “you don’t need a magnitude 9 to cause extensive damage,” though it was careful to mention that part of the reason for that is that California’s buildings are not as earthquake resistant as those in Japan.
A great piece from the Associated Press had more detail about the Golden State’s feeble infrastructure, pointing out, among other things, that “California’s five-year-old program for helping cash-strapped public schools seismically retrofit their most vulnerable buildings has so far disbursed only a tiny portion of the $200 million set aside under the effort. The San Francisco-Oakland Bay Bridge, damaged in the 1989 earthquake, still hasn’t been replaced. Thousands of old hospitals and apartment buildings remain despite being at serious risk in a quake.” (The San Diego Union Tribune published a letter from a member of the Structural Engineers Association of California calling on government to work more closely with the group to ensure public safety.)
Henderson’s article for Reuters cited a second 2008 report from the USGS, which concluded that there is 99 percent probability that California will experience one or more magnitude 6.7 or greater quakes in the next thirty years, and a 46 percent chance that it will experience one or more magnitude 7.5 or greater quakes in that time. The report also concluded that about three magnitude 5 or greater quakes will occur in the state per year, and that a magnitude 6 or greater quake will happen about every one-and-a-half years.
Gorman’s article for Reuters reported that a major California earthquake is “long overdue,” although it did not elaborate or provide any supporting evidence. For such detail, one would have to turn to MSNBC.com, which quoted an earthquake expert at the University of California at Davis, John Rundle, explaining that historical analyses show that there is a major temblor along the San Andreas about every 160 years and that the last one was in 1857, 154 years ago. Along the Cascadia subduction zone, which stretches from Vancouver Island to Northern California in the Pacific Northwest (and features the Juan de Fuca plate sliding under the North American plate), there is a major event every about 500 years and the last one was in 1700, 311 years ago (an AFP article, however, quotes a geotechnical engineer at the Oregon Department of Geology who says the fault ruptures more like every 240 years).