The 9.0 earthquake that struck Japan on March 11 not only sent a tsunami barreling across the Pacific, but also waves of concern about natural disaster preparedness and nuclear safety elsewhere.

In United States, the media have paid particularly close attention to California, home to two nuclear power plants and the country’s most damaging temblors, and second only to Alaska in total number of quakes. The question on every reporter’s mind: could the same devastation meted out in Japan also befall the Golden State? Dozens of articles have tried to answer that question, but the information they have provided about the latest developments in earthquake science has been less than comprehensive.

Two headlines in particular had commentators scratching their heads (emphasis added):

• “Special report: Big California quake likely to devastate state” (Reuters, March 14)
• “Japan-style earthquake and tsunami unlikely to hit Southern California, experts say” (Los Angeles Times, March 14)

Which is it? Good question. The first article, by Peter Henderson, starts by painting a portrait of a dystopian, earthquake-ravaged future that is clearly meant to startle readers into paying attention:

California will experience unthinkable damage when the next powerful quake strikes, probably within 30 years, even though the state prides itself on being on the leading edge of earthquake science.

Modern skyscrapers built to the state’s now-rigorous building codes might ride out the big jolt that experts say is all but inevitable, but the surviving buildings will tower over a carpet of rubble from older structures that have collapsed.

Hot desert winds could fan fires that quakes inevitably cause, overwhelming fire departments, even as ancient water pipelines burst, engineers and architects say.

Part of the lesson from the disaster that hit Japan on Friday is that no amount of preparation can fully protect a region such as California that sits on top of fault lines.

Henderson’s introduction relies heavily on scare tactics and is, in some respects, overwrought. The future he sketches is based on a 2008 report from the United States Geological Survey (USGS), which the article goes on to quote saying, “The question is not if, but when Southern California will be hit by a major earthquake - one so damaging that it will permanently change the lives and livelihoods in the region.”

Titled “The ShakeOut Scenario,” the report describes the consequences of a hypothetical 7.8 earthquake on the southern San Andreas fault, which causes widespread destruction. It’s a grisly read, to be sure, but when Henderson reported that the analysis “predicted 2,000 deaths and $200 billion damage,” he failed to mention that that’s only “if we take no additional actions for preparedness and mitigation.” His article also didn’t explain that while the USGS emphasizes that its scenario (based on geologic, seismic, and socio-economic data and modeling) is “realistic,” and should be used for planning and preparedness purposes, it is not prediction.

“The next earthquake will be different in details for the ShakeOut earthquake, and its total damages and losses will differ, because each earthquake produces its own patters of shaking and damages,” the report said. “However, the widespread, regional effects will be similar, and so will the long-term social and economic impacts.”

Indeed, while Reuters risked pandering to readers, and news reporters should not emulate the purple prose of its lede, its article may have been closer to the mark the one from the Los Angeles Times, whose headline read, “Japan-style earthquake and tsunami unlikely to hit Southern California, experts say.”

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.

Curtis Brainard is the editor of The Observatory, CJR's online critique of science and environment reporting. Follow him on Twitter @cbrainard.