Identify the landslide and earthquake hazards as well as related ground deformation processes that have great potential to impact the social and economic well being of the inhabitants of the Southern California coastal region.
Description
Chief Scientist: Bill Normark. Geophysical data (GPS, 12khz, Huntec, airgun, 24channel) of field activity O-1-99-SC in Southern California from 06/05/1999 to 06/17/1999
Location
Southern California
Summary
Continue surveying (the second of four planned data collection cruises) the coastal zone between Santa Monica and San Diego; MCS and Huntec data will be used to identify the active faults in the nearshore zone and to assess the seismic hazards expected.
Info derived
High-resolution multichannel (MCS) and Huntec seismic-reflection profiles to image the faults and to use dating of sediment -core samples to establish timing and rates of movement on the faults.
Comments
physical data holdings
California continental borderland: Pt Conception to San Dieigo, CA Lines with tags a, b, c, etc. are all planned lines. a, b, etc. were added to the full line name when something in the lab changed during the line (i.e., for mcs, the blue screen of death or some other problem, or for huntec, if the paper ran out or the recording disks ran out). a and b indicators were used independently for mcs and huntec, so they will can not be correlated between the two systems. Once or twice we did the a planned line in two segments on different days (I think 247,247a or 245,245a is one time this happened), but this will show up on with the time indicators. The tags "dl" or "dm" mean dog legs, between planned lines. MCS may have been on during this time, but probably were not recorded. "dm" was used as a,b was noted above. 99l: planned line on the 085 degree or 040 degree trends (Im not sure of the actual orientation of the lines, so dont quote me.) In general (but not every time) MCS was on for these. There are a couple of exceptions. 99n: Huntec-only lines run at night in any orientation.
Staff information imported from InfoBank
Bill Normark (USGS Western Region) - Chief Scientist
Jane Reid (USGS Western Region) - Watchstanding: Navigation & Huntec
Ray Sliter (USGS Western Region) - Watchstanding: Mutichannel Seismic
Dave Holton (Environmental Careers Organization) - Watchstanding: Navigation & Huntec
Larry Kooker (USGS Western Region) - Electronics Technician
Fred Payne (USGS Western Region) - Electronics Technician
Kevin O'Toole (USGS Western Region) - Mechanical Technician
Hal Williams (USGS Western Region) - Mechanical Technician
Graham Standen (Geoforce Consultants) - Huntec Specialist
Jen Quan (Cascadia Research Collective) - Marine Mammal Observer
Annie Douglas (Cascadia Research Collective) - Marine Mammal Observer
Tamara Guenther (Cascadia Research Collective) - Marine Mammal Observer
Russ Brisendine (F/V North Wind, Inc.) - Ship Captain
Jeff Stringer (F/V North Wind, Inc.) - 1st Mate
Dave Malsch (F/V North Wind, Inc.) - Engineer
Mike Hill (F/V North Wind, Inc.) - Cook
Paul Giron (F/V North Wind, Inc.) - 2nd Mate
Joe Kelly (F/V North Wind, Inc.) - A/B
Non USGS data manager = Christina Gutmacher
Multichannel seismic (MCS) data were collected by the U.S. Geological Survey (USGS) in June of 1999 in the coastal zone and continental shelf between Los Angeles and San Diego, offshore California (USGS field activity O199SC). In 2021 these data were reprocessed to improve accuracy and resolvability of geologic structures and fault systems of California’s continental margin.
Multichannel seismic-reflection (MCS) data were collected in the California Continental Borderland as part of southern California Earthquake Hazards Task. Five data acquisition cruises conducted over a six-year span collected MCS data from offshore Santa Barbara, California south to the Exclusive Economic Zone boundary with Mexico. The primary mission was to map late Quaternary deformation as well as identify and characterize fault zones that have potential to impact high population areas of southern California. To meet its objectives, the project work focused on the distribution, character, and relative intensity of active (i.e., Holocene) deformation along the continental shelf and basins adjacent to the most highly populated areas. In addition, the project examined the Pliocene-Pleistocene record of how deformation shifted in space and time to help identify actively deforming structures that may constitute current significant seismic hazards.
The MCS data accessible through this report cover the first four years of survey activity and include data from offshore Malibu coastal area west of Santa Monica, California to the southern survey limit offshore San Diego. The MCS data, which were collected with a 250-m-long, 24-channel streamer used a small gas-injector airgun source. This system provided optimum resolution of the upper 1 to 2 km of sediment for mapping active fault systems. The report includes trackline maps showing the location of the data, as well as both digital data files (SEG-Y) and images of all of the profiles.
These data are also available via GeoMapApp (http://www.geomapapp.org/) and Virtual Ocean ( http://www.virtualocean.org/) earth science exploration and visualization applications.
