Scientists and KRON 4 are using Tuesday morning's tiny quake on the Hayward Fault as an excuse to remind us all that a big and potentially deadly earthquake is due "any day now," as has been discussed many times over the past twenty years. Just a couple months ago we had another unsettling reminder via a new report that focused on the possibility of two faults co-rupturing in the Bay Area.
We currently face a 95 percent chance of another Loma Prieta-sized (6.9M) quake in the next few years, with a strong likelihood of that quake coming from The Hayward Fault. There's a 76 percent chance of a much bigger quake of 7.0 or greater, and furthermore, the Hawyward Fault has two spots of possible co-rupture with another fault: the Rodgers Creek Fault in Napa to the north, and the Calavares Fault to the south.
The last time the Hayward Fault busted open was way back in 1868, causing what would be known for the ensuing few decades, until 1906, as The Great San Francisco Earthquake. That quake is believed to have been about Loma Prieta-sized, 6.8 or so, but caused a fair bit of damage to the then much less populated Bay Area. 30 people were killed in that "forgotten" quake, and obviously a new quake on the Hayward Fault would likely cause far more widespread damage than that one 147 years ago.
Scientists caution, though, that Tuesday's quake is no indication that a bigger quake is imminent. But, of course, that's not to say that foreshocks aren't a thing and CalTech experts explain, "foreshocks cannot be positively identified as foreshocks until after the mainshock has occurred."
SO, once again, and I need to take this advice too: Get your earthquake kit together.