Northern California Struck by 6.0 Magnitude Earthquake

[Cowboy72A]

An earthquake with a preliminary magnitude of 6.0 shook the northern San Francisco Bay area early Sunday, the U.S. Geological Survey reported.
Leslie Gordon of the U.S. Geological Survey that the tremor struck at just before 3:30 a.m. Sunday about 10 miles northwest of American Canyon, which is about six miles southwest of Napa.
The USGS says it's the largest tremor to shake the Bay Area since the 1989 6.9 magnitude Loma Prieta quake and that the depth of the quake was less than seven miles with several small aftershocks
Thus far, there have been reports of power outages and property damage, but no immediate official reports of injury

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The earthquake that rattled Napa Valley and other parts of northern California on Sunday measured 6.0 on the magnitude scale. That was strong enough to damage buildings, injure 87 people, and leave thousands without power.

It was also the biggest quake in the Bay Area since the Loma Prieta earthquake in 1989 that wreaked havoc in Santa Cruz, San Francisco, and Oakland. That one measured 6.9 on the magnitude scale and caused far more destruction — killing 63 people and injuring 3,757.

So how did the two earthquakes compare in terms of actual shaking on the ground? The map below, put together by UC Davis geologist Dawn Sumner, shows the difference. The 1989 earthquake (on the right) had much more violent shaking throughout the region:

The 2014 Napa quake (magnitude 6.0) vs the 1989 Loma Prieta quake (magnitude 6.9)

It's worth remembering that the scale that geologists use to measure the size of the energy released by an earthquake is logarithmic. That means that a magnitude 6.9 earthquake releases roughly 22 times as much energy as a magnitude 6.0 earthquake.

That said, the amount of ground shaking that actually occurs depends on a variety of additional factors besides magnitude — the depth at which the earthquake takes place, how far away the quake is, the type of rock and soil in the region, as well as how the seismic waves propagate through the Earth's crust.