Transcript Slide 1
Earthquakes and the Hayward Fault Presented by the UC Berkeley Seismological Laboratory Courtesy of NISEE, EERC, UC Berkeley Flour Mill, 1868 Hayward EQ Q: What is an Earthquake? Rocks break… Waves spread out… Photo: Horst Rademacher A: MASSIVE Energy is Released! Manifested at Earth’s surface as SHAKING and property damage. Image courtesy of the USGS Image courtesy of the USGS What is Plate Tectonics? The Earth’s crust is broken up into large “plates”. These plates move around, driven by heat escaping from inside the Earth. One “Plate” Planet Earth’s Plates Image Courtesy of the USGS Where do we Find Earthquakes? Image courtesy of NASA Every single black dot is one recorded earthquake... The Infamous “Ring of Fire”! Image Courtesy of the USGS Home in Hayward, CA Faults of the Bay Area We live in earthquake country! What is the Hayward Fault? • Standing on one side of the fault, the other side will appear to move to the right. Image from the Southern California Earthquake Data Center Image Courtesy of CSU Hayward Where is the Hayward Fault found? •The Hayward Fault runs along the base of the East Bay Hills. •Currently, the fault is thought to have an earthquake recurrence interval of about 170±29 years! •If the last earthquake occurred in 1868… Image courtesy of USGS Historical Bay Area Earthquakes • Hayward, M 7.0, 1868 – Along the Hayward Fault • South Hayward, M 5.8, 1865 – Along the Hayward Fault • Loma Prieta, M. 6.9, 1989 – Along the San Andreas Fault MORAL OF THE STORY: Bay Area earthquakes have occurred in the past and will occur again in the future. We need to be prepared! Image courtesy of the USGS How do We Measure Earthquakes? • Seismic waves leave an Earthquake’s “focus” and move out through the Earth. • Seismologists record these waves at Earth’s surface, using seismometers. Image Courtesy of USGS Public Domain Seismometers, Past and Present 130 C.E. 2009 C.E. Time Image Courtesy of the USGS Image Courtesy of Alfred Wegener Institute for Polar and Marine Research Life near the Hayward Fault Image Courtesy of Doris Sloan Image Courtesy of Doris Sloan How Can We Prepare for an Earthquake? • Make an earthquake preparedness kit! – Food, water, matches, flashlight, batteries, blankets and SHOES! All will be very hard to come by following a large earthquake! Public Domain Public Domain Public Domain What Should We do During an Earthquake? During shaking: YOU (as quickly as possible) After shaking has stopped, move outside AWAY from structures.