A magnitude 4.2 earthquake shook Southern California's San Fernando Valley just before 4:30 a.m. on Thursday, the United States Geological Survey said. However, when you live in earthquake country, you might want to give the question a second thought. The San Fernando earthquake has been extensively studied by many seismologists, geologists, and earthquake … The unanticipated thrust earthquake had a moment magnitude of 6.5 or 6.7 (as determined by several independent institutions) and … Forty-six years ago today, the possibility of such a sudden dam burst was the hair-raising fear, in the chaos and devastation following the magnitude 6.7 earthquake that struck the San Fernando Valley north of Los Angeles.  |  1771 Words 8 Pages. 28:14. This paper compares the distribution of damage from the San Fernando, 1971, and Northridge, 1994, earthquakes. At the 140-ft high Lower dam, the entire upstream face slid into the reservoir leaving only 5 ft of freeboard. This shaking occurs when stress that builds up in the crust is … Within the southern California region alone, the historic record suggests that an earthquake of about this magnitude occurs on the average of once every four years ( Fig. "Earthquake" captures all the drama, suspense, pathos, and even humor, of the San Fernando Valley Quake of 1971. The documentary moves along quickly and uses actual newsreel footage as well as well-staged re-enactments, blended together in a leanly edited narrative. List of earthquakes in California - Wikipedia The section of freeway in Sylmar, California that was intended to open first (between Interstate 5 and Maclay Avenue) was damaged by the 1971 … USGS 'Sylmar Quake' or 'Sylmar earthquake' is … Much like the Northridge Earthquake 23 years later, the quake also tore apart freeway overpasses. The worst damage was done here being newly opened (one Today in Earthquake History, February 9, 2017  The 1971 San Fernando earthquake, also known as the “Sylmar Quake,” took place on the morning of February 9, 1971 around 6:01am. At the 140-ft high Lower dam, the entire upstream face slid into the reservoir leaving only 5 ft of freeboard.  |  University Library Contributing Institution California State University, Northridge Collection San Fernando Valley History Rights Information This is the Olive View Medical Center. It also occurred on a hitherto unknown fault, albeit a different one from the San Fernando fault (see Figure 2). The 1971 San Fernando (a.k.a. Although the Richter magnitude of the tremblor was 6.6, ranking it as moderate to large, but not great, it shook a wide, … Seismologists call it the San Fernando earthquake. Source: USGS, How right they were was demonstrated 23 years later, when almost the same areas of the San Fernando Valley were again struck by a damaging earthquake. At the time, the 1971 San Fernando earthquake was the most destructive event to affect greater Los Angeles since the magnitude-6.3 Long Beach earthquake of 1933. San Fernando Valley. The Slides in the San Fernando Dams During the Earthquake of February 9, 1971. The earthquake that rocked the northern San Fernando Valley, near Sylmar measured magnitude 6.6 on the Richter magnitude scale. The colored dots represent locations of the respective aftershocks of each quake. But the threat of disaster didn't end when the shaking stopped. • The epicenter of the magnitude 6.6 disastrous earthquake was in the foothills of the San Gabriel Mountains, at the northeastern edge of the Valley. In the end, the dam held and the evacuees were allowed to return to their homes. 21st century Contemporary era. Mapping of the surface breaks that resulted from the San Fernando earthquake of 9 February 1971 reveals that the pattern of faulting was highly complex; it consisted of a number of … Earthquakes are best described as a shaking or vibration of the ground caused by breaking of rock. The 1971 San Fernando Earthquake, by Bob Burnside "County Recurrent" is pleased to present another story from Chief Bob Burnside, Ret., this time with respect to the Sylmar Earthquake that struck early in the morning on Feb. 9, 1971, and resulted in one of the earliest multi-lifeguard agency swift water response that we know of in … Browse more videos. By the late 1990s, the San Fernando Valley had become more urban and more ethnically diverse with rising poverty and crime. The earthquake that rocked the northern San Fernando Valley, near Sylmar measured magnitude 6.6 on the Richter magnitude scale. Significant Earthquakes and Faults Chronological Earthquake Index San Fernando Earthquake. There are various names for this earthquake. Even more surprising was the location of the focus of the quake, which later came to be known as the San Fernando earthquake. 1771 Words 8 Pages. C. R. Allen and his co‐workers assigned the main shock parameters: 34°24.7′N, 118°24.0′W, focal depth h = 8.4 km, and … In comparison, both the Loma Prieta (1989) and Northridge (1994) quakes measured “IX Violent” on the Mercalli Scale, two steps below this quake (the Sylmar Earthquake, 1971). 4-5. Instead of … Type of Faulting: thrust Time: February 9, 1971 / 6:01 am PST Location: 34° 24.67' N, 118° 24.04' W Magnitude: M W 6.5 Depth: 8.4 km Fault Involved: San Fernando fault zone; minor offset reported on the eastern Santa Susana fault zone Also known as the Sylmar Earthquake, this earthquake … Some decades later, the San Fernando earthquake affected the San Fernando Valley north of Los Angeles with heavy damage to several hospitals. Sometimes they are very strong and other times you would hardly notice them. 1. Sometimes they are very strong and other times you would hardly notice them. @article{osti_7345945, title = {Response of power systems to the San Fernando Valley earthquake of 9 February 1971. San fernando earthquake of 9 february 1971: pattern of faulting. The 1971 San Fernando earthquake (also known as the Sylmar earthquake) occurred in the early morning of February 9 in the foothills of the San Gabriel Mountains in southern California. Special San Fernando Earthquake Edition SEISMOLOGIC AND CRUSTAL MOVEMENT INVESTIGATIONS OF THE SAN FERNANDO EARTHQUAKE By Roger Greensfelder SEISMOLOGY Fault mechanism and aftershocks The aftermath led to major changes for building construction and the Alquist-Priolo Act. San Fernando Valley earthquake of Feb. 1971, Sylmar, California Public Domain English: The 1971 San Fernando earthquake in the San Fernando Valley, Los Angeles County, California. ‘The Incredibles' Lead a New Safety Campaign in OC and LA, Free Or Cheap Things Angelenos Can Do From Home, Disney Artifacts Go to Auction in Honor of Walt's Birthday, Wind and Red Flag Weather Drive Fires in Southern California Ahead of Holidays, Copyright © 2020 NBCUniversal Media, LLC. The red line is the fault on which the Northridge quake occurred in 1994. Type of Faulting: thrust Time: February 9, 1971 / 6:01 am PST Location: 34° 24.67' N, 118° 24.04' W Magnitude: M W 6.5 Depth: 8.4 km Fault Involved: San Fernando fault zone; minor offset reported on the eastern Santa Susana fault zone Also known as the Sylmar Earthquake, this earthquake occurred … Below, a look back at the Sylmar Earthquake. On Feb. 9, 1971, the deadly San Fernando Earthquake rattled Southern California, leaving more than 60 people dead and causing more than $500 million in property damage. The 6.6 magnitude earthquake with an epicenter located along a 12 mile fault zone below the San Gabriel Mountains lasted approximately 12 seconds and affected the entire San Fernando Valley. Objects under such forces would have been weightless for a few seconds, like astronauts in space.  |  The epicenter of the quake was located in the San Gabriel Mountains, with numerous nearby Los Angeles communities affected. See more ideas about sylmar, earthquake, san fernando valley. The February 9, 1971 earthquake in San Fernando Valley, California, caused slides in the embankments of two old adjacent hydraulic fill dams. The two blue lines mark the faults which ruptured in the San Fernando earthquake 46 years ago today. Most dams are constructed well and they are built for eternity. The Symlar San Fernando Valley Earthquake of 1971. The question of whether it is wise to live below a dam behind which millions of acre feet of water are stored is usually rather low on people's lists of daily worries. 1971 May 14;172(3984):712-5. : San Fernando Juvenile Hall, after earthquake, 1971 : Foothill Freeway after earthquake, 1971 : Olive View Medical Center after the 1971 Sylmar quake, before demolition Yerkes -- Main shock and larger aftershocks of the San Fernando earthquake, February 9 through March 1, 1971 / C.R. Mapping of the surface breaks that resulted from the San Fernando earthquake of 9 February 1971 reveals that the pattern of faulting was highly complex; it consisted of a number of segments that produced ground displacements and acceleration throughout the entire northern end of the San Fernando Valley.  |  The two geologists Carl Wentworth and Robert Yerkes from the US Geological Survey in Pasadena later wrote that "the San Fernando fault was discovered to be active only when it ruptured the ground surface on February 9, 1971. Saved from scvhistory.com Create . Categories:   The earthquake that rocked the northern San Fernando Valley, near Sylmar measured magnitude 6.6 on the Richter magnitude scale. Palmer DF, Henyey TL. There were the Watts Riots, the assassination of Robert F. Kennedy at The Ambassador Hotel, Charles Manson, the Chicano Moratorium in East Los Angeles, the ongoing destruction of the original Bunker Hill, the Sunset … 24, No. San Fernando Valley Natural Disasters Southern California Old Houses Childhood Memories Melbourne Around … 2:38. How destructive was this quake on February 9, 1971? Also known as the Sylmar Earthquake, the magnitude-6.5 quake was reported on a Tuesday at about 6:01 a.m. Its origin was in the foothills of the San Gabriel Mountains north of Los Angeles, but shaking was felt across a widespread part of the San Fernando Valley. May 1, 2020 - Explore David's board "sylmar earthquake 1971" on Pinterest. The February 9, 1971 earthquake in San Fernando Valley, California, caused slides in the embankments of two old adjacent hydraulic fill dams. When seismologists checked their records they were utterly surprised. Reported with each aftershock like the Northridge quake occurred in 1994 ; 172 ( 3984:712-5. 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