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ID
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F-2-95-NC
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Abstract
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United States Geological Survey, Menlo Park, California.
Chief Scientists: Sam Clarke, Andy Stevenson. Geological and
Geophysical data (Geopulse, 7khz, 200khz, pcode) of field
activity F-2-95-NC in Big Lagoon, Stone Lagoon - Northern
California from 09/27/1995 to 09/29/1995
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Organization |
United States Geological Survey, Menlo Park, California
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Project/Theme
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Crustal Earthquake Hazards
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Chief Scientist
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Sam Clarke
Andy Stevenson
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Activity Type
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Geological and Geophysical
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Platform
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Fast Eddy
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Area of Operation
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Big Lagoon, Stone Lagoon - Northern California, Northern California
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Bounding Coordinates
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41.75000
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-125.75000 -122.25000 |
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37.75000 |
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Dates
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09/27/1995 (JD 270) to 09/29/1995 (JD 272)
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Analog Materials
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No analog holdings.
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Crew
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Equipment Used
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Geopulse
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7khz
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200khz
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pcode
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Purpose
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To obtain evidence of faulting and other coseismic
deformation from lagoonal sediments in water bodies developed on the
lower plates of thrust faults in an active forearc thrust belt. Data
will be used to locate core sites for follow-on coring program to date
fault offset and determine deformation rates.
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Information to be Derived
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High-resolution seismic reflection data from upper 10-30 m of
sedimentary section. Seismic reflection profiles with interpretation; possibly,
bathymetric maps of the lagoons.
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Summary
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Successful in Big and Stone Lagoons, with 1/8 and 1/4 sec Geopulse, 1/8
sec 700 kHz, and 200 kHz fathometer data obtained both. Minor problems with GPS
locations. Water level in Lake Earl was too low (~4' MSL) to permit launch of
Fast Eddy at available launch sites. Plan to return to Lake Earl when lake level
is greater than ~6 ft MSL.
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Notes
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Analog records from the systems employed. The seemingly annual
end-of-the-fiscal-year fun in northern California-Oregon this year involved
collection of high-resolution seismic data from Big Lagoon and Stone Lagoon
north of Eureka, California.
The crew of Sam Clarke, Andy Stevenson, and Dave Hogg aboard "Fast" Eddy
collected 40 lines of Geopulse, 7kHz, and 200 Khz data from the lagoons, seeking
evidence of faulting and coseismic deformation from the lower plates of thrust
faults in an active forearc thrust system.
We hope that this information will ultimately contribute to knowledge of
earthquake recurrence intervals and magnitudes. There were some
difficulties with P-code GPS locations, and interpretation remains, but the
data look good and should provide bonus information on processes related to
flushing and filling of the lagoons. The water level in Lake Earl, near
Crescent City, was too low to launch Eddy, so we missed one target. Great
weather (mostly), elk herds, river otter, and a brief road race with a
black bear -- geology at its best.
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Got Help?
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For F-2-95-NC, we would appreciate any information on -- analog materials, contract, days at sea, dive count, funding, information specialist, kms of navigation, national plan, NGDC Info, owner, ports, project number, publications, scanned materials, seismic description, station count, station description, submersible, tabulated info.
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