Seafloor mapping in the offshore Ft Ord region to characterize the nature of the seafloor morphology and geology
Description
Chief Scientist: Steve Eittreim. Data (multibeam, GPS, CTDmeter) of field activity P-1-95-MB in Monterey Bay from 07/29/1995 to 08/02/1995
Location
Monterey Bay
Summary
175 square kilometers were swath-mapped covering most of the southern Monterey Bay shelf with the exception of the outer shelf beyond 95 m water depths; coverage included the shelf northwest of Monterey Peninsula. The data is hampered by some noise problems due to rough weather and to patchiness in water velocity distributions and to wave motion of the transducer vertically through the thermocline. 2-meter, shaded-relief contour maps at 1:5000 have been produced and the backscatter imagery maps are still in the data-processing stage.
Info derived
2-m bathymetry and acoustic imagery
Comments
Physical data holdings
Associated activities: M-1-93-MB J-1-94-MB J-2-95-MB J-6-95-MB M-2-95-MB P-1-95-MB P-3-95-MB R-1-95-MB M-1-96-MB J-1-97-MB J-3-97-MB A-4-98-MB J-3-98-MB J-4-98-MB (from USGS Bulletin 8/18/95) The Monterey Bay National Marine Sanctuary Project was the beneficiary of a high-resolution multibeam bathymetric survey last week as Humboldt State Universitys R/V PACIFIC HUNTER mowed the grass on the southern Monterey Bay shelf. The 5- day survey revealed a new trend of seafloor mounds in a north-south alignment northward out from the Peninsula. A relationship to the Monterey Bay fault zone is suggested by the linear edges of some of these mounds, parallel to the Monterey Bay fault zone. Both swath bathymetry and backscatter imagery were collected and gave complimentary information about the seafloor geology. The nearshore sand-bands/ribbons, previously mapped by Hunter et al, were imaged in detail, as was the major pipeline south of the Salinas River. Our crew of Steve Eittreim, Andy Stevenson and Roberto Anima were coached by the visiting dean of multibeam, Larry Mayer of the Univ. of New Brunswick, Canada. The Simrad EM- 1000 system, apparently the state of the art in multibeam bathy, was in some contrast to the platform used: The PACIFIC HUNTER is a 1927 refitted 125-foot coast guard cutter recently given a new life as research vessel, thanks to gargantuan efforts on the part of folks at HSU. She will be berthed at Redwood City for a couple of weeks before repair of one engine and the trek back to Humboldt Bay.
Staff information imported from InfoBank
Steve Eittreim (USGS Western Region) - Chief Scientist
Derived contours at 10-m intervals are from data collected by the USGS with a multibeam (Simrad EM1000) sidescan sonar system in the southern Monterey Bay between Moss Landing and Monterey, California in 1995 (USGS Field Activity P1-95-MB). This is one of a collection of digital files of a geographic information system of spatially referenced data related to the USGS Coastal and Marine Geology Program Monterey Bay National Marine Sanctuary Project (see this and other older Monterey Bay USGS works archived at https://archive.usgs.gov/archive/sites/walrus.wr.usgs.gov/monterey/index.html.
