![]() This temblor fractured along at least five fault segments. This shift in thinking was propelled by the magnitude 7.3 earthquake that shook Landers, California, in 1992. “And then over time, as the data has gotten better and better, we’ve started to realize that there’s potential for multiple faults to rupture for single events.” “Historically, the thought has been that earthquakes occurred on individual faults,” he says. While such complex quakes are not unheard of, recent research suggests that they may be more common than once believed, explains Zachary Ross, a geophysicist at the California Institute of Technology. Of particular interest in these quakes is that at least the first temblor seemed to have simultaneously broken two sections of faults that cut across each other at nearly a right angle. The shaking was also widespread, with reports of light ground movements as far as Chico, California, and Phoenix, Arizona. While no deaths or major injuries have yet been reported, the intensity of the ground movement was quite strong-enough to send goods flying off store shelves and buildings swaying. ![]() They seemed to have occurred along the same set of faults, located in an area known as the Little Lake fault zone. ![]() The recent events are what’s known as strike-slip earthquakes, which occur when two blocks of Earth shift side-by-side, grinding past each other. Learn about the geophysics behind earthquakes, how they are measured, and where the most powerful earthquake ever witnessed occurred. “How is it working? How is it accommodating plate motion? What are going to be the big structures that come out of this millions of years down the road?”Įarthquakes can leave behind incredible devastation, while also creating some of the planet's most magnificent formations. “The Eastern California shear zone is a really interesting area,” says Wendy Bohon, an earthquake geologist at the Incorporated Research Institutions for Seismology (IRIS). It’s crisscrossed by fractures in the Earth caused by the movement along the nearby tectonic plate boundary. The area extends from the southern Mojave Desert, up the eastern side of the Sierra Nevada, and into western Nevada. ![]() The duo of quakes struck in what’s known as the Eastern California shear zone-an area east of the infamous San Andreas fault, where the Pacific Plate grinds against the North American Plate, creeping northwest at roughly two inches each year. And they promise to yield fresh clues about its complex geology. While earthquakes are not unexpected, the two most recent temblors are the largest that have struck this area in decades. But that wasn’t all the Earth had in store: Less than a day and a half later, a powerful magnitude 7.1 temblor shook the region. Usually, California experiences two or three earthquakes large enough to cause damage to buildings.On the morning of July 4, a magnitude 6.4 rocked Southern California, fracturing roads and sending people fleeing to safety. ![]() National Earthquake Information Center reports that 12,000-14,000 earthquakes occur annually. Hilary continues to bring torrential rain with potentially life-threatening flooding through at least Monday. "However, periods of heavy precipitation or of drought might indirectly affect earthquake-prone faults." Therefore, it’s unlikely that seismic hazard is affected by precipitation," the USGS said. "There is no pattern in California of large, damaging earthquakes occurring more frequently during periods of heavy precipitation or periods of drought. USGS ShakeAlert."Īt least a dozen aftershocks with several above 3.0 magnitude were reported after the initial quakeĪt last update, the tropical storm was less than 100 miles from San Diego. The alert message stated: "Earthquake detected! Drop, cover, hold on. Some residents reported receiving an alert on their phones in the moments before the earthquake. Video taken in Thousand Oaks, CA shows a chandelier swaying after a 5.1 magnitude earthquake was reported northwest of Los Angeles 5.1 Magnitude earthquake shakes Southern California ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |