Everyone knows that California’s San Andreas fault is a ticking time bomb ready to erupt – but a new study shows that another fault right under the East Bay is far more dangerous. The Hayward fault could decimate major cities like Oakland and Berkeley, killing hundreds and destroying tens of thousands of homes. And according to scientists, “it’s just waiting to go off.”

This week, scientists published a landmark study that detailed a 52-mile fault centered under Oakland, California. If the fault were to erupt – and it is only a matter of time until it does – the US Geological Survey estimates the toll would include at least 800 killed, 18,000 injured, 400,000 displaced and 52,000 homes destroyed. Most homes would be destroyed by the 400 fires scientists estimate would ignite, and the shattered water infrastructure would complicate firefighter’s efforts to put them out.

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“This fault is what we sort of call a tectonic time bomb,” USGS earthquake geologist emeritus David Schwartz said. “It’s just waiting to go off.” There are certainly larger faults out there (like the San Andreas), but what makes the Hayward fault so deadly is that 2 million people live right on top of it. For reference, the 1906 quake that devastated San Francisco was centered off the coast and impacted a city of 400,000 residents.

The Hayward fault is relatively active, with a major earthquake every 150 years or so (give or take 75 years). Its last major earthquake – a 6.8 – was 150 years ago this October. In 1989, the 6.9 Loma Prieta shook the Bay Area and caused about 60 deaths and $82 billion in damage. A similar quake on the Hayward fault today would be 10 times as bad, and even homes that stood during the Loma Prieta quake could be shattered.

The bottom line is that the cities and citizens along the fault need to work to improve infrastructure, secure homes and make sure that they are prepared for the next big one. It’s easy to get complacent when it has been a while since the last earthquake, scientists say, but that’s when you have to be most prepared.

Via LA Times

Images via Jeff Pierre