In southern California, the last rupture of the San Andreas Fault occurred in 1857. The relative movement along the fault varied from 2 to 32 feet (0.5 m to 9.7 m), which means if two people were standing on opposite sides of the fault, in some places one would slide away from each other by up to 32 feet from the other. The San Andreas Fault first captured the world’s attention on that fateful April day 116 years ago when it ruptured along the northernmost 296 miles (477 km) of the 800 mile- (1300 km) long fault that marks where the Pacific plate slides by the North American plate. ![]() “If some of these older earthquakes are misidentified, then the long wait we are currently experiencing might be more typical.” “The wait between earthquakes might be longer than we previously thought because the evidence for older earthquakes isn’t always 100% accurate,” McPhillips said. In a new publication, USGS geologist Devin McPhillips studied sites along three faults in California with long histories of earthquakes to better understand what’s happening. Although no one can predict when an earthquake will occur, scientists can better assess seismic hazards by calculating the probability of a ground-rupturing earthquake occurring in a specific area within a certain number of years.Ĭonsidering the historical average rate of large earthquakes on some faults in California, including the San Andreas, the odds that there hasn’t been a major earthquake in the last 116 years are very low. Researchers study older significant earthquakes like this one to better understand how frequently they strike on a fault. The earthquake and subsequent fires killed an estimated 3,000 people and left half of the city’s 400,000 residents homeless. The magnitude 7.9 quake caused shaking that lasted up to 60 seconds and sent vibrations all the way to southern Oregon, Los Angeles, and central Nevada. The Great San Francisco Earthquake struck at 5:12 a.m. Quakes between 2.5 and 5.4 in magnitude are often felt, but only cause minor damage, according to Michigan Tech’s UPSeis website.ĬNN’s Emily Smith contributed to this report.The San Andreas may be the most well-known fault in California, but no one alive today experienced its most recent significant earthquake that ruptured 116 years ago. The situation is still fluid and the agency is “actively coordinate with local police and fire personnel to evaluate things like roofs, foundations and infrastructure at sensitive sites like schools and hospitals,” Ferguson said.Įarthquakes are measured using seismographs, which monitor the seismic waves that travel through the Earth after an earthquake strikes. PT, USGS data shows, which was about five minutes after the original 5.1 magnitude earthquake. Seven Trees also experienced a smaller 2.9 magnitude earthquake at 11:47 a.m. Preliminary information from USGS shows the earthquake was 7.2 kilometers (4.5 miles) deep. The USGS did report another earthquake Tuesday – this time a 3.6 magnitude that struck around 3:08 p.m. EQCZ4r07AT- USGS Earthquakes October 25, 2022 Watch this video to learn more about today’s San Francisco Bay Area earthquake with Dr. “If you do feel shaking don’t forget to drop, cover and hold on.” “Aftershocks of this magnitude and duration are totally normal for an event of this type,” she said. Annemarie Baltay, a USGS seismologist, said Tuesday “there could be 10-15 aftershocks of magnitude 3 or greater in the next week.” ![]() Preliminary reports do not indicate any significant damage or injuries, the emergency services office told CNN.ĭr. “Advance notice varied from two seconds for those very near the epicenter to 18 seconds for those in the San Francisco,” Ferguson said. PT.Ībout 100,000 people received an advanced notification from the Earthquake Warning California app, the state’s early warning system, before shaking started, according to Brian Ferguson, deputy director for crisis communication and public affairs for the California Governor’s Office of Emergency Services. Preliminary information from the USGS says the quake was 6.9 kilometers (4.2 miles) deep and hit around 11:42 a.m. The US Geological Survey (USGS) reported a 5.1 magnitude earthquake in Seven Trees, near San Jose, California on Tuesday.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |