Geological survey and the national oceanic and atmospheric administration. Please leave this template in place to link the article histories and preserve this attribution. The former pages history now serves to provide attribution for that content in the latter page, and it must not be deleted so long as the latter page exists. The total surface rupture was roughly 19 km 12 miles long. The liquefaction slide nearly caused a major uncontrolled release of the reservoir. The quake ripped open the surface for about 12 miles in the mountains and san fernando valley. Earthquake induced deformation analyses of the upper san fernando dam under the 1971 san fernando earthquake guoxi wu abstract. The largest events in the san fernando earthquake series, initiated by the main shock at 14h 00m 41. The 1971 san fernando earthquake also known as the sylmar earthquake happened in the early morning of february 9 in the san gabriel mountains.
A preliminary report by reuben kachadoorian, arthur grantz, carl m. Material from 1971 san fernando earthquake was split to sierra madre fault zone on 23. Lessons from a moderate earthquake on the fringe of a densely populated region. During the san fernando, california earthquake of february 9, 1971 buildings in the strongly shaken region showed both types of performance.
The quake ripped open the surface for about 12 miles in the mountains and san fernando valley, knocked down parts of the sfv veterans hospital and. Front matter san fernando earthquake of february 9, 1971. Did the zones with severely damaged buildings reoccur. San fernando dam during the 1971 san fernando earthquake in california, just to name a few. Download a pdf of san fernando earthquake of february 9, 1971 by the national research council for free. Check out the record album the radio station mad from that day. This paper compares the distribution of damage from the san. Nearby lower san fernando dam was damaged even more severely, and would have probably led to an uncontrolled release if the reservoir elevation had not been restricted prior to the earthquake. Simple dislocation fault models of the san fernando, california, earthquake of 1971 as deduced from leveling data have been presented with emphasis on an abrupt change in dip angle of fault plane. Analysis of the pacoima dam accelerogramsan fernando. A little known fact was that the van norman dam was. It is postulated that the initial event took place at depth on the sierra madre fault zone which runs along the base of the san gabriel mountains. The 1971 san fernando earthquake, also known as sylmar earthquake, struck the san fernando valley near sylmar at 6.
An extensive summary of the worldwide standardized seismograph network, including detailed description of all wwssn stations. Southern california earthquake data center at caltech. Earthquake reconnaissance and effects on structures 1971 san fernando or sylmar earthquake oblique air view southeast of collapsed structures at interchange of highways 5 and 210. The san fernando earthquake of february 9, 1971 in southern california initiated a major slide on the downstream slope of upper san fernando dam. San fernando california earthquake february 9 1971 abebooks. Severe damage of the dam during the 1971 san fernando earthquake forced residents to evacuate homes in a 6milelong area down the valley. The red line is the fault on which the northridge quake occurred in 1994. The 1971 san fernando earthquake occurred in the early morning of february 9 in the foothills of the san gabriel mountains in southern california. The effect on state highways of the san fernando earthquake, february 9, 1971 california. We evacuated because the van norman dam was cracked, and they thought it. San fernando earthquake series, 1971 focal mechanisms and tectonics james h. San fernando earthquake conference 50 years of lifeline. Engineering aspects of the 1971 san fernando earthquake. Knowledge gained from this event initiated the study of lifeline systems worldwide, including water, wastewater, electric power.
As a result of the many effects of the earthquake, a large number of detailed studies and reports will be forthcoming from a wide variety of sources, and the papers collected in this volume are only preliminary. The san fernando earthquake, 1971 video dailymotion. Eeri preliminary engineering findings report pdf newsletter articles. The historical san francisco earthquake of 1906 measured the same xi extreme in four locations just to the north of san francisco, but the city itself only felt x. San fernando, california, earthquake of february 9, 1971. San fernando valley sylmar earthquake 1971 youtube. The collapse of curved overpass was due to seismic shaking and to lateral extension of the north and south abutments thereby shortening the chord. Fernando, california, earthquake february 9, 1971, ml.
Pdf the response of veterans hospital building 41 in the san. Later known as the san fernando earthquake, the quake was responsible. A sheriffs deputy stands outside the collapsed olive view hospital following the quake. The quakes epicenter was located five miles north of the san fernando valley, near the. 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. After the partial collapse of the van norman dam in the san fernando earthquake, the water came dangerously close to overtopping. Pdf elastic finitedifference modeling of the 1971 san. Before the 1971 san fernando earthquake early media reports refer to this event as the sylmar earthquake while seismologists use the name san fernando earthquake, it was assumed that operational loads on bridges presented more severe structural requirements for. The division of earth sciences there fore established the joint panel on the san fernando earth quake to draw from the event and its effects. San fernando, california earthquake engineering research. The san fernando earthquake has been extensively studied by many seismologists, geologists, and earthquake engineers. Request pdf 1971 san fernando and 1994 northridge, california, earthquakes.
The san fernando, california, earthquake of february 9. The earthquake that rocked the northern san fernando valley, near sylmar measured magnitude 6. The death toll of this earthquake was about 58, but the property damage was enormous. Special san fernando earthquake edition the 1971 san fernando earthquake an hour before sunrise, at 6. The colored dots represent locations of the respective aftershocks of each quake. Sylmar got its name on the event, but the epicenter was deep under the san gabriel mountains, in the san fernando fault zone. The unanticipated thrust earthquake had a moment magnitude of 6. Search for library items search for lists search for contacts search for a library. Evidence is presented which suggest that the 1971 san fernando earthquake may have been a double event that occurred on two separate, subparallel thrust faults.
A nonlinear effective stress finite element approach for dynamic analysis of soil structure is described in. Wentworth, et al and a great selection of related books, art and collectibles available now at. Hileman seismological laboratory, california institute of technology pasadena, california 91109 the largest events in the san fernando earthquake series, initiated by the main. The faulting mechanism of the san fernando earthquake.
A study of source finiteness in teleseismic body waves bulletin of the seismological society of america an exact solution for a finite, twodimensional moving dislocation in an elastic halfspace with application to the san fernando earthquake of 1971. San fernando, california, earthquake of 9 february 1971. Feb 22, 2016 on february 9th, 1971, at approximately 6. Mar 06, 2016 on february 9th, 1971, at approximately 6. Earthquakes on two blind thrust faults caused severe damage in the san fernando valley. Earthquake reconnaissance and effects on structures. Because of the magnitude of the slide and strong interest of the engineering profession in the evaluation of the seismic stability of earth dams, the lower san fernando dam slide has received. San fernando, california, earthquake of 9 february 1971 by oakeshott, gordon b. This was an after shock of the feb 9th 1971 earthquake. The san fernando, california, earthquake of february 9, 1971. Article from the february 1971 newsletter pdf other reports.
Examples of such catastrophes include the 1964 alaska earthquake, the san fernando earthquake of 1971, the guatemala earthquake in 1976, the 1987 ecuador earthquake, the kobe earthquake in 1995, and the 2003 algeria earthquake. Because of its consequences, the san fernando earthquake was a major earthquake from the engineering point of view, even though it was only a moderate shock in seismological terms. United states earthquakes, 1971 openfile report 84971 prepared. San fernando, california, earthquake of february 9, 1971 united states. A state of emergency in california after the most serious earthquake since the san. The recently completed freeway interchange in the north san fernando. The february 9, 1971 san fernando california earthquake was a devastating yet seminal event which, for the first time, demonstrated the seismic threat to lifelines that fundamentally support our modern livelihoods. Relation of known faults to surface ruptures, 1971 san fernando. Engineering features of the san fernando earthquake of.
Seismograms of the 1971 san fernando california earthquake. The earthquake that hit southern california caused part of massive elevated freeway to collapse, burying the 80ton crane bottom which had been used in work on. Oct 01, 2009 the 1971 san fernando earthquake also known as sylmar earthquake struck the san fernando valley near sylmar at 6. San fernando earthquake an overview sciencedirect topics. Survey of japanese design requirements for bri dges. Before the 1971 san fernando earthquake early media reports refer to this event as the sylmar earthquake while seismologists use the name san fernando earthquake, it was assumed that operational loads on bridges presented more severe structural requirements for bridges than did earthquakes.
Teleseismic p, sv, and sh waves recorded by the wwss and canadian networks from the 1971 san fernando, california earthquake ml 6. In the san fernando earthquake, the number of deaths 65, of people sustaining serious injuries over 1,000 and amount of major structural damage was almost entirely confined to portions of san fernando and tujunga valleys, and the newhallsaugus area map, page 62. San fernando earthquake 1971 today in history 9 feb. It was at the northern edge of the san fernando valley in southern california. Also known as the sylmar earthquake, this earthquake occurred on the san fernando fault zone, a zone of thrust faulting which broke the surface in the sylmar san fernando area. Presented also are the most widely accepted methods for evaluating the liquefaction potential of cohesionless oils in level ground, for estimating earthquake induced settlements and. The two blue lines mark the faults which ruptured in the san fernando earthquake 46 years ago today.
San fernando earthquake series, 1971 focal mechanisms. 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 magnitude of 6. The damage was severe near the san fernando valley. 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. Earthquakeinduced deformation analyses of the upper san.