leg 1: identify fault and landslide hazards in the offshore area of Southern California. The study areas were selected to (a) obtain multichannel and high-resolution seismic-reflection data inside the 3-mile limit between Port Hueneme and the Mexican border; and (b) extend data coverage within a relatively unsurveyed segment of the margin seaward of the shelf between Dana Point and San Diego, California. leg 2: to obtain multichannel and high-resolution data in Los Angeles/Long Beach harbor and adjacent shelf for study of salt-water intrusion in local aquifers.
Description
United States Geological Survey, Menlo Park, California. Chief Scientists: Chris Gutmacher, Stephanie Ross, Brian Edwards. Geophysical data (12khz, Huntec, uniboom, Geopulse, minisparker, minisparker, GPS, YoNav, 24channel, sparker) of field activity A-1-00-SC in Southern California from Port Hueneme to Mexican Border from 06/05/2000 to 06/29/2000
Location
Southern California from Port Hueneme to Mexican Border
Summary
Extensive high-resolution geopulse and huntec data were collected within the 3-mile limit and farther seaward in areas sparsely surveyed during previous operations, as well as in the Los Angeles / Long Beach harbor and adjacent shelf. Problems with the minisparker power supplies prevented its use during much of the cruise, despite unflagging efforts by the shipboard engineering and electronic technicians. In the end, only 36 hours of multichannel minisparker data were collected in the harbor/shelf area and an additional 10 hours in the shelf and slope area east of Port Hueneme. 1200 line-km geopulse (960 hazards, 240 aquifers) 1400 line-km huntec (1300 hazards, 100 aquifers) 470 line-km minisparker (100 hazards, 370 aquifers)
Info derived
Identify and map active and potentially active faults, folds, and submarine slide-prone areas that may threaten densely populated areas of Southern California. Map pathways of salt-water intrusion into local aquifers critical to the large population of the greater Los Angeles metropolitan area.
Comments
physical holdings
Staff information imported from InfoBank
Chris Gutmacher (Watchstander, USGS Western Region) - Chief Scientist
Stephanie Ross (Watchstander, USGS Western Region) - Chief Scientist
Brian Edwards (USGS Western Region) - Chief Scientist
Larry Kooker (USGS Western Region) - Electronics Technician
Kevin O'Toole (USGS Western Region) - Mechanical Technician
Ray Sliter (channel Seismic Watchstander, USGS Western Region) - Multi
Becky Cooper (USGS Western Region) - Watchstander Navigation
Pat Hart (channel Seismic Watchstander, USGS Western Region) - Multi
Jon Childs (channel Seismic Watchstander, USGS Western Region) - Multi
Dave Gonzales (USGS Western Region) - Electronics Technician
Jane Reid (USGS Western Region) - Watchstander
Dave Hogg (USGS Western Region) - Electronics Technician
Tim Elfers (USGS Western Region) - Mechanical Technician
Walt Olson (USGS Western Region) - Mechanical Technician
Martin Uyesugi (Geoforce Consultants) - Huntec Engineer Watchstander
Annie Douglas (Cascadia Research) - Mammal Observer
Lisa Baraff (Cascadia Research) - Mammal Observer
Dave Ellifrit (Cascadia Research) - Mammal Observer
Todd Chandler (Cascadia Research) - Mammal Observer Team Leader
Jr Veldink (Cascadia Research) - Mammal Observer
Dick Corrigan (Northwind Shipyards) - Captain
Ted Blinkers (Northwind Shipyards) - Captain
Jeff Stringer (Northwind Shipyards) - Mate
James Stacey (Northwind Shipyards) - Engineer
Ricky Labrador (Northwind Shipyards) - Cook
Rich Soderblom (Northwind Shipyards) - Deck Hand
Brad Scarrott (Applied Acoustic Engineering) - Minisparker Technician
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.
