USGS CMG 04020 Metadata

Piston coring and gravity coring of Storegga slide off Norwegian coast

Samples and chemical analysis, grain size analysis, Sea floor map, bathymetric 
maps

Geotechnical-related devices and supplies provided by USGS WH Geotech Lab
32 Stations Occupied.

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