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Geotechnical-related devices and supplies provided by USGS WH
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Geotech lab (vane shear machine, pocket penetrometer, Torvane).
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Some supplies provided by USGS WH Chem Lab.
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Jumbo piston corer, Giant gravity corer, Multi-sensor Track.
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Scientists from the U.S. Geological Survey s Coastal and
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Marine Geology program participated in a joint cruise with the
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Monterey Bay Aquarium Research Institute (MBARI) and the Woods Hole
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Oceanographic Institute (WHOI) aboard the RV Knorr. The National
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Science Foundation funded the 14-day cruise to investigate the
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characteristics of sediment surrounding and within the massive
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Storegga submarine slide as a precursor to potential drill sites of
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the Integrated Ocean Drilling Program (IODP). The slide, located on
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the Mid-Norwegian margin, is one of the largest known mass-wasting
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events encompassing a movement of approximately 5,600 km3 of
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material, with a headwall scarp 300 km in length with a down slope
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movement of over 800 km. It is thought the current extent of the
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slide may actually be the result of at least three different events
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beginning 50,000 years ago to as recent as 6,000 years ago. Evidence
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suggests that one part of the slide caused a tsunami that impacted
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parts of Norway and Scotland. Bottom Simulating Reflectors (BSR),
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indicative of gas-hydrate containing sediment overlying gas-charged
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sediment, have been found in seismic-reflection records from the
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slide area. This leads to speculation that hydrate dissociation,
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which releases gas molecules from trapped hydrogen-bonded cages and
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increases pore pressure, may have contributed to the slide. The
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objective of the cruise was to estimate the amount of gas still left
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within sediment under the slide and compare it to the amount of gas
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in the surrounding regions. This information is to be used in
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determining the mechanism that induced the slide as well as proved
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insight into the present conditions of surrounding sediment.
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Representatives from a number of organizations participated in the
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cruise. Charlie Paull, Bill Ussler (co-chief scientists), Joel
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Johnson, Patrick Mitts, and Rendy Keaton from the Monterey Bay
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Aquarium Research Institute; Steve Holbrook (project PI), Jeff
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Nealon, and Hillary Brown from the University of Wyoming; Tom
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Lorenson (USGS CMGP, Menlo Park) and Bill Winters (USGS CMGP, Woods
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Hole); Tessa Hill from the University of California Santa Barbara;
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Julia Frazier from the University of California Santa Cruz; Michelle
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Hatton from Florida State University; Ulla Knudsen from the
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University of Arhus (Denmark); Ellen Roosen, Mike McCarthy, Peter
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Lemmond, Amy Simoneau, and Chrissy van Hilst from WHOI.
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Core-related: Coring attempts: 32 Cores recovered: 27 Giant gavity
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cores recovered: 12 Jumbo piston cores recovered: 15 Analyses
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performed: Geotechnical measurements including shear strength
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determination (USGS-WH) Multi Sensor Track measurements of P-wave
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velocity, magnetic susceptibility (MBARI) Pore water sulfate
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gradients (MBARI) Gas isotopes (USGS-MP)
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