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USGS Coastal and Marine Geology Program

Field Activity Details for field activity P195MB

AKA: none

Other ID: P-1-95-MB

Status: Completed


Funding Program(s): Monterey Bay National Marine Sanctuary (MU182)

Principal Investigator(s): Steve Eittreim

Affiliate Investigator(s):

Information Specialist(s):

Data Type(s): Environmental Data: CTD, Location-Elevation: Navigation, Sonar: Multibeam, Sonar: Sidescan

Scientific Purpose/Goals: Seafloor mapping in the offshore Ft Ord region to characterize the nature of the seafloor morphology and geology


Start Port/Location:

End Port/Location:

Start Date: 1995-07-29

End Date: 1995-08-02

Equipment Used: multibeam, GPS, sidescansonar, CTD

Information to be Derived: 2-m bathymetry and acoustic imagery

Summary of Activity and Data Gathered: 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.


Affiliate Staff:

Notes: 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


Monterey Bay

North: 36.77509 South: 36.60737 West: -121.9927 East: -121.82182


Pacific Hunter


Eittreim, S.L., and Noble, M., 2002, Seafloor geology and natural environment of the Monterey Bay National Marine Sanctuary: Marine Geology, v. 181 no. 1-3, pp. 1–2, doi: 10.1016/S0025-3227(01)00258-4.

Wong, F., and Eittreim, S., 2001, Continental Shelf GIS for the Monterey Bay National Marine Sanctuary: U.S. Geological Survey Open-File Report 01-179,


Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
multibeam --- Multibeam
File list
GPS --- Navigation
Global positioning system (GPS) data p-1-95-mb.061 (Provisional best file)
Global positioning system (GPS) data p-1-95-mb.061_5min
Global positioning system (GPS) data p-1-95-mb.060
Best file with nav in ArcInfo E00 format
Global positioning system (GPS) data p-1-95-mb.061_degree
sidescansonar --- Sidescan
sidescan (data on FAD)
CTD --- Surveys (geochemical)
Experiments (geochemical)

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