The Whittier Narrows, California Earthquake of October 1, 1987—Emergency Response

1988 ◽  
Vol 4 (1) ◽  
pp. 25-30 ◽  
Author(s):  
R. Andrews
Keyword(s):  
Los Angeles ◽  
Private Sector ◽  
Emergency Response ◽  
Southern California ◽  
Seismic Event ◽  
Local State ◽  
Metropolitan Region ◽  
San Fernando ◽  
Made In

The Whittier Narrows earthquake of October 1, 1987 was the most significant seismic event to occur in southern California since the San Fernando earthquake of February 1971. As such, the 5.9 magnitude temblor provided a basis for evaluating the level of preparedness in at least a portion of the Los Angeles metropolitan region. The Whittier Narrows event provides a hint of the progress that has been made in local, state and private sector preparedness in the last six years as well as suggesting areas that need additional effort.

scholarly journals Performance of Two 18-Story Steel Moment-Frame Buildings in Southern California during Two Large Simulated San Andreas Earthquakes

2006 ◽  
Vol 22 (4) ◽  
pp. 1035-1061 ◽  
Author(s):  
Swaminathan Krishnan ◽  
Chen Ji ◽  
Dimitri Komatitsch ◽  
Jeroen Tromp
Keyword(s):  
Los Angeles ◽  
Southern California ◽  
Building Code ◽  
Los Angeles Basin ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Existing Building ◽  
San Andreas ◽  
Frame Buildings ◽  
San Fernando

Using state-of-the-art computational tools in seismology and structural engineering, validated using data from the Mw=6.7 January 1994 Northridge earthquake, we determine the damage to two 18-story steel moment-frame buildings, one existing and one new, located in southern California due to ground motions from two hypothetical magnitude 7.9 earthquakes on the San Andreas Fault. The new building has the same configuration as the existing building but has been redesigned to current building code standards. Two cases are considered: rupture initiating at Parkfield and propagating from north to south, and rupture propagating from south to north and terminating at Parkfield. Severe damage occurs in these buildings at many locations in the region in the north-to-south rupture scenario. Peak velocities of 1 m.s−1 and 2 m.s−1 occur in the Los Angeles Basin and San Fernando Valley, respectively, while the corresponding peak displacements are about 1 m and 2 m, respectively. Peak interstory drifts in the two buildings exceed 0.10 and 0.06 in many areas of the San Fernando Valley and the Los Angeles Basin, respectively. The redesigned building performs significantly better than the existing building; however, its improved design based on the 1997 Uniform Building Code is still not adequate to prevent serious damage. The results from the south-to-north scenario are not as alarming, although damage is serious enough to cause significant business interruption and compromise life safety.

scholarly journals Palmdale Bulge and its significance

1978 ◽  
Vol 11 (3) ◽  
pp. 193-194
Author(s):  
G. J. Lensen
Keyword(s):  
Los Angeles ◽  
Southern California ◽  
Los Angeles Basin ◽  
Epicentral Area ◽  
Transverse Ranges ◽  
The Future ◽  
San Fernando ◽  
Maximum Subsidence

As an aftermath to the 1971 San Fernando earthquake in southern California two existing levelling routes were relevelled in order to assess the amount of earth shift that triggered this earthquake. Comparison of
the new and old data revealed two important points: (a) the 1971 earthshift resulted in a maximum uplift of 2 m on the upthrown (Transverse Ranges) side and a maximum subsidence of 110 mm on the downthrown (Los Angeles basin complex) side. (b) prior to the 1971 earthshift the area was deforming for at least 10 years, reaching over the period 1968-69 the maximum of about 80 mm uplift in the future epicentral area.

The Sunland Grizzly

2014 ◽  
Vol 91 (4) ◽  
pp. 56-63
Author(s):  
Josh Sides
Keyword(s):  
Los Angeles ◽  
Los Angeles County ◽  
Southern California ◽  
Grizzly Bear ◽  
Science And Art ◽  
Founding Director

In 1916, Cornelius Birket Johnson, a Los Angeles fruit farmer, killed the last known grizzly bear in Southern California and the second-to last confirmed grizzly bear in the entire state of California. Johnson was neither a sportsman nor a glory hound; he simply hunted down the animal that had been trampling through his orchard for three nights in a row, feasting on his grape harvest and leaving big enough tracks to make him worry for the safety of his wife and two young daughters. That Johnson’s quarry was a grizzly bear made his pastoral life in Big Tujunga Canyon suddenly very complicated. It also precipitated a quagmire involving a violent Scottish taxidermist, a noted California zoologist, Los Angeles museum administrators, and the pioneering mammalogist and Smithsonian curator Clinton Hart Merriam. As Frank S. Daggett, the founding director of the Los Angeles County Museum of History, Science and Art, wrote in the midst of the controversy: “I do not recollect ever meeting a case where scientists, crooks, and laymen were so inextricably mingled.” The extermination of a species, it turned out, could bring out the worst in people.

scholarly journals A revised position for the primary strand of the Pleistocene-Holocene San Andreas fault in southern California

2021 ◽  
Vol 7 (13) ◽  
pp. eaaz5691
Author(s):  
Kimberly Blisniuk ◽  
Katherine Scharer ◽  
Warren D. Sharp ◽  
Roland Burgmann ◽  
Colin Amos ◽  
...  
Keyword(s):  
Los Angeles ◽  
Southern California ◽  
San Andreas Fault ◽  
Slip Rate ◽  
Large Magnitude ◽  
Slip Rates ◽  
San Andreas ◽  
The Pacific ◽  
Large Earthquakes ◽  
Dependent Probability

The San Andreas fault has the highest calculated time-dependent probability for large-magnitude earthquakes in southern California. However, where the fault is multistranded east of the Los Angeles metropolitan area, it has been uncertain which strand has the fastest slip rate and, therefore, which has the highest probability of a destructive earthquake. Reconstruction of offset Pleistocene-Holocene landforms dated using the uranium-thorium soil carbonate and beryllium-10 surface exposure techniques indicates slip rates of 24.1 ± 3 millimeter per year for the San Andreas fault, with 21.6 ± 2 and 2.5 ± 1 millimeters per year for the Mission Creek and Banning strands, respectively. These data establish the Mission Creek strand as the primary fault bounding the Pacific and North American plates at this latitude and imply that 6 to 9 meters of elastic strain has accumulated along the fault since the most recent surface-rupturing earthquake, highlighting the potential for large earthquakes along this strand.

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