The 1971 San Fernando, or Sylmar, earthquake was the worst to hit an urban area of California since the 1933 magnitude-6.4 Long Beach quake. [1] Hay varios nombres para este terremoto.Los sismólogos lo llaman el terremoto de San Fernando. The shaking was felt from Los Angeles in the south to Coos Bay, Oregon, in the north. But at 42 seconds after 6 a.m. on a Tuesday morning 25 years ago this week, Feb. 9, 1971, the Sylmar-San Fernando earthquake hit the Valley and … Later known as the San Fernando Earthquake, the quake was responsible for $500 million dollars worth of damage and causes 65 deaths (most of the deaths occurred when the Veteran's Administration Hospital collapsed). The colored dots represent locations of the respective aftershocks of each quake. Categories:   Here are six interesting facts about The Sylmar Earthquake you may never have known about. Earthquake hits the San Fernando Valley area of California. It prompted Governor Ronald Reagan to declare Los Angeles County a disaster area and President Richard Nixon to send Vice President Spiro Agnew to inspect the area. As we go to press one month later, 65 lives have been charged to it, and damage has been estimated at more than half a billion dollars. In the southern California area--from Point Arguello to Nevada and from the Mexican border to Owens Valley--seismic records suggest that 37 shocks of this magnitude or greater might be expected in a century; indeed, one might expect two shocks with a magnitude of 8.0 or more. More chunks of earth collapsed with each new aftershock, reducing the height of the crown and bringing the water table dangerously close to the top of the dam (see Figure 1). This earthen dam had partially liquefied and the top 30 feet of the edifice had crumbled. Types of data acquired from dwelling inspections after the 1971 San Fernando earthquake A3 1984 When it was apparent that the landslide potential of the hillsides, though great, did not threaten any urban areas, the geologists turned their attention to the study of geologic effects--so often ephemeral--and to other geologic hazards that may have been developed or increased by the earthquake. An hour before sunrise, at 6:01 AM, PST, on February 9, 1971, the San Fernando region was struck by one of the most devastating earthquakes in California history. Messrs. Gray and Caldwell went immediately to the Los Angeles District Office where they maintained constant contact with field, administrative, and disaster staffs. Feb 9, 2015 - 1971 San Fernando highway overpass collapse - 1971 San Fernando earthquake - Wikipedia, the free encyclopedia The San Fernando Fault, located 6 mi northwest of Burbank's downtown, caused the 6.6 magnitude 1971 San Fernando earthquake. Los Angeles Times. The San Fernando earthquake (also known as the Sylmar earthquake) was a magnitude 6.6 earthquake that struck on February 9th, 1971 at 6:00 AM PST. USGS 'Sylmar Quake' o 'Sylmar earthquake' es el nombre … It was the first strong quake to hit the area since the 1893 Pico Canyon quake, with an epicenter several miles west of Sylmar. Over the range 15 to 300 km, the data are distrib-uted log-normally about an inverse power law relation with an exponent of -1.5, as indicated by the heavy line in Fig. Photo: E. Leyendecker, USGS. Dr. Thomas Heaton, the director of Caltech’s Earthquake Engineering Research Laboratory, breaks it down. The 1971 earthquake has enabled him to add another facet to the study of the area he now knows so well. It led to 64 deaths and more than $500 million in damage. See more ideas about sylmar, earthquake, san fernando valley. The San Fernando earthquake occurred in 1971 with a magnitude of 6.6. Aug 27, 2015 - 1971 san fernando earthquake - Google Search 50th Anniversary of the February 9, 1971 San Fernando Earthquake Experts available to share historical insights and earthquake resiliency. San Fernando Rd. One of the hardest-hit buildings was the just-completed San Fernando Veterans Administration Hospital, whose unreinforced concrete wings collapsed, killing at least 44 people.  |  Dam failure Open in Our App. The 6.6 magnitude Sylmar earthquake rumbled across the San Fernando Valley at about 6 a.m. on Feb. 9, 1971. Although the 1971 San Fernando earthquake and the near failure of the Lower Van Norman Dam have given rise to construction improvements — the … The 1971 earthquake was a massive disaster resulting in collapsed freeways, destroyed homes, and way too many ruined… By that time, much of the area had been built over; new base maps were available, and many new roads provided road cuts to give new looks at the geology. More than once have dams failed or were overtopped due to the shaking of large earthquakes - with devastating consequences for the people living downstream. The presence in California of major universities with strong and active earthquake research The 1971 earthquake was a massive disaster resulting in collapsed freeways, destroyed homes, and way too many ruined… But the threat of disaster didn't end when the shaking stopped. Had the earthquake hit at rush hours, when the streets and freeways were full of traffic; had it hit during school hours, when schools were filled with children--our grief might be much greater. Even more surprising was the location of the focus of the quake, which later came to be known as the San Fernando earthquake. Three Division geologists had an especial interest in the area, as well as especial expertise. Charlie Bishop came from San Francisco, as well as several staff members from Sacramento-Quint Aune, Chief Wes Bruer, Bob Matthews, and Bennie Troxel. Geologists had known for a long time that the San Gabriel Mountains above the San Fernando Valley were riddled with faults. It is evident, however, that more faults in the San Fernando Valley area may be active today than are now recognized." But even now, after further detailed studies, they are not sure whether they have identified all blind faults in the area or if the valley's inhabitants are in for more surprises. 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.The unanticipated thrust earthquake had a moment magnitude of 6.5 or 6.7 (as determined by several independent institutions) and had a maximum Mercalli intensity of XI (Extreme). Also known as the San Fernando earthquake, the Feb. 8, 1971, magnitude-6.5 quake happened on a Tuesday at about 6:01 a.m. Its origin was in the foothills of the San … 1 - The 1971 Earthquake Is Holding Up New Development In Hollywood  |  When it was all said and done, the 1971 Sylmar-San Fernando earthquake claimed 64 lives. When seismologists checked their records they were utterly surprised. A little known fact was that the Van Norman … The epicenter was located approximately 10 km northeast of LSFD at a focal depth of approximately 9 km. Although the Richter magnitude of the tremblor was 6.6, ranking it as moderate to large, but not great, it shook a wide, heavily populated area, leaving death and destruction in its wake. The landslides they mapped included those in the eastern half of the San Fernando quadrangle. The Newhall Pass infrastructure project which is located northwest of the San Fernando Valley in Weldon Canyon and less than eight miles from two other major freeway interchanges, prompted Councilman Donald Lorenzen to criticize conglomeration of freeways and connectors as “putting too many eggs in one basket.” Never before had such a strong acceleration been recorded in an earthquake. Damage was severe in San Francisco and in other towns situated near the San … The two blue lines mark the faults which ruptured in the San Fernando earthquake 46 years ago today. There was no movement on the faults near the hospital; damage to the building has been attributed to the intense shaking to which it was subjected. A seismograph of the San Fernando earthquake in southern California in 1971 shows (top) ground acceleration, (center) velocity, and (bottom) displacement. From left: Duane L. Georgeson, Jules Bergman examine damage in the aftermath of the Sylmar Earthquake / 1971 San Fernando earthquake, in the Walt Disney Television via Getty Images / GE Monogram se… It was determined that the magnitude was 6.7. Preparedness, Risks, and Hazards On the day following the earthquake, State Geologist Wesley Bruer convened a meeting of more than 40 geologists and seismologists engaged in studying the earthquake, so that all investigative activities might be coordinated. Learn More. The earthquake was generated by thrust faulting on the Sierra Madre fault. This station is part ofthe NOAA accelerograph network. Freeway interchanges collapsed (killing two men in a pickup truck under one fallen overpass), reservoirs were in danger of imminent failure, forcing people living below them to evacuate, and houses and commerical buildings collapsed or caught fire. On February 9, 1971, just after 6:00 a.m., a M6.5 earthquake struck the San Gabriel mountains, in the northwestern part of Los Angeles County. The 1971 San Fernando earthquake (also known as Sylmar earthquake) struck the San Fernando Valley near Sylmar at 6:00:55 a.m. PST on Feb. 9, 1971…  |  Sort of shook up excuse the the community and uh and certainly the political communities um forced us to start taking earthquake … Later, scientists at UCLA estimated that flooding following the collapse of the dam could have killed between 70,000 and 120,000 people. Despite the losses, gains made through earthquake hazard mitigation efforts of the last two decades were obvious. The biggest seismic jolt in 80 years struck the northeast San Fernando Valley before dawn — flattening freeway overpasses, collapsing hospitals, toppling power stations, sparking fires and threatening to burst dams and flood the homes of tens of thousands.When the dust cleared on the 1971 Sylmar-San Fernando earthquake 45 years ago Tuesday, 64 people lay dead and more than 2,500 … High Acceleration We must hurry to learn what we can, and to put to use what we know, while our luck holds.... M.R.H.  |  A preliminary report of their investigations is presented in this magazine. This early and continuing exchange has added significantly to the effectiveness of the investigations. The red line is the fault on which the Northridge quake occurred in 1994. However, deaths and injuries were How the 1971 Sylmar earthquake helped improve public structures in California. The greatest damage was in the San Fernando area, near the front of the San Gabriel Mountains, where three hospitals were badly damaged (one of them accounting for the greatest loss of lives). WHAT: On February 9, 1971, a magnitude 6.6 earthquake struck in San Fernando, CA at 6 a.m. An hour before sunrise, at 6:01 AM, PST, on February 9, 1971, the San Fernando region was struck by one of the most devastating earthquakes in California history. ", Figure 2: Earthquakes on two blind thrust faults caused severe damage in the San Fernando Valley. In 1962, the Division inaugurated a study of the frontal fault system along the San Gabriel Mountains. They paid particular attention to hillsides that might give way in aftershocks, causing more havoc than already existed. When the dust cleared on the 1971 Sylmar-San Fernando earthquake 45 years ago Tuesday, 64 people lay dead and more than 2,500 lay injured beneath more than $550 million in …