Separation of Site Effects and Structural Focusing in Santa Monica, California: A Study of High-Frequency Weak Motions from Earthquakes and Blasts Recorded during the Los Angeles Region Seismic Experiment

2002 ◽  
Vol 92 (8) ◽  
pp. 3134-3151 ◽  
Author(s):  
S. Baher
Keyword(s):  
Los Angeles ◽  
High Frequency ◽  
Site Effects ◽  
Seismic Experiment ◽  
Santa Monica

Report for air-gun data acquired at onshore stations during the 1994 Los Angeles Region Seismic Experiment (LARSE), California

1995 ◽  
Author(s):  
D.A. Okaya ◽  
Joyjeet Bhowmik ◽  
G.S. Fuis ◽  
J.M. Murphy ◽  
M.C. Robertson ◽  
...  
Keyword(s):  
Los Angeles ◽  
Air Gun ◽  
Seismic Experiment

scholarly journals Report for explosion data acquired in the 1994 Los Angeles Region Seismic Experiment (LARSE 94), Los Angeles, California

1996 ◽  
Author(s):  
J.M. Murphy ◽  
G.S. Fuis ◽  
Trond Ryberg ◽  
D.A. Okaya ◽  
E.E. Criley ◽  
...  
Keyword(s):  
Los Angeles ◽  
Seismic Experiment

Multiscale seismic imaging of active fault zones for hazard assessment: A case study of the Santa Monica fault zone, Los Angeles, California

Geophysics ◽  
1998 ◽  
Vol 63 (2) ◽  
pp. 479-489 ◽  
Author(s):  
Thomas L. Pratt ◽  
James F. Dolan ◽  
Jackson K. Odum ◽  
William J. Stephenson ◽  
Robert A. Williams ◽  
...  
Keyword(s):  
High Resolution ◽  
Los Angeles ◽  
Hazard Assessment ◽  
Seismic Reflection ◽  
Seismic Profile ◽  
Strike Slip ◽  
Alluvial Fan ◽  
Depth Range ◽  
Seismic Reflection Profile ◽  
Santa Monica

High‐resolution seismic reflection profiles at two different scales were acquired across the transpressional Santa Monica Fault of north Los Angeles as part of an integrated hazard assessment of the fault. The seismic data confirm the location of the fault and related shallow faulting seen in a trench to deeper structures known from regional studies. The trench shows a series of near‐vertical strike‐slip faults beneath a topographic scarp inferred to be caused by thrusting on the Santa Monica fault. Analysis of the disruption of soil horizons in the trench indicates multiple earthquakes have occurred on these strike‐slip faults within the past 50 000 years, with the latest being 1000 to 3000 years ago. A 3.8-km-long, high‐resolution seismic reflection profile shows reflector truncations that constrain the shallow portion of the Santa Monica Fault (upper 300 m) to dip northward between 30° and 55°, most likely 30° to 35°, in contrast to the 60° to 70° dip interpreted for the deeper portion of the fault. Prominent, nearly continuous reflectors on the profile are interpreted to be the erosional unconformity between the 1.2 Ma and older Pico Formation and the base of alluvial fan deposits. The unconformity lies at depths of 30–60 m north of the fault and 110–130 m south of the fault, with about 100 m of vertical displacement (180 m of dip‐slip motion on a 30°–35° dipping fault) across the fault since deposition of the upper Pico Formation. The continuity of the uncomformity on the seismic profile constrains the fault to lie in a relatively narrow (50 m) zone, and to project to the surface beneath Ohio Avenue immediately south of the trench. A very high‐resolution seismic profile adjacent to the trench images reflectors in the 15 to 60 m depth range that are arched slightly by folding just north of the fault. A disrupted zone on the profile beneath the south end of the trench is interpreted as being caused by the deeper portions of the trenched strike‐slip faults where they merge with the thrust fault.

John Ballard and the African American Community in Los Angeles, 1850–1905

2012 ◽  
Vol 94 (2) ◽  
pp. 193-229
Author(s):  
Patty R. Colman
Keyword(s):  
African American ◽  
Los Angeles ◽  
Black Community ◽  
Economic Status ◽  
Political Activism ◽  
African American Community ◽  
Property Ownership ◽  
Santa Monica Mountains ◽  
Santa Monica ◽  
Institution Formation

John Ballard, an African American pioneer from Kentucky, became a leader of Los Angeles's black community, 1850s–1870s. His story illustrates the early opportunities for black Angelenos in institution-formation, political activism, property ownership, and economic success. However, with the railroad booms of the 1870s and 1880s, Ballard and other prominent black citizens suffered a loss of social and economic status. Ballard ended up homesteading in the Santa Monica Mountains.

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