Biggest quake in 25 years hits Northern California

By Casey Frye, CCNN Writer

tectonic plates
The Earth is broken up beneath the crust into massive pieces called tectonic plates. Volcanoes and earthquakes are common at their edges.

While California is known for its quakes, especially in the Los Angeles area, the famous Napa Valley wine country in the north is usually very peaceful. However, the region got a rude awakening on Sunday morning when a 6.0-magnitude earthquake struck. Buildings were tossed around and injuries were plentiful in the strongest Northern California shakeup in 25 years.

Governor Jerry Brown declared a state of emergency, as the quake’s impact on the San Francisco Bay Area caused upwards of $1 billion in damage. Windows exploded and residents talked about being thrown into the air from their beds. Fortunately, injuries were mostly minor, despite some folks taking trips to the hospital. The tremors could be felt even 120 miles away in Salinas.

Despite citizens feeling shaken up, in more ways than one, the 1906 San Francisco earthquake was about 500 times larger than the one on Sunday. See, quakes are measured on the Richter magnitude scale, named after Charles Francis Richter. He was a famous seismologist – an Earth scientist who studies the physical movements of the ground – and his scale goes from under 2.0 (microquakes you can barely feel) all the way to 9.0 and greater, meaning total destruction of just about everything. A quake that’s 6.0-6.9 is described as dealing damage to a moderate number of well-built structures in areas with big populations.

What causes these geological events? Well, the Earth’s crust is broken up into 17 “tectonic plates” that shift around, and the plate boundaries are hotspots for pressure being released in the form of earthquakes and volcanoes. Plus, there’s a mega crack in the ground in California called the San Andreas Fault, which is where the Pacific Plate meets the North American Plate. This makes the state particularly vulnerable to shakeups.

Featured image courtesy of Matthew Keys on Flickr. Image of tectonic plates courtesy of US Geological Survey.