HR: 17:30h
AN: C32C-06    [PDF]
TI: Opportunities and Challenges for Arctic Geoscience in the IPY (International Polar Year)
AU: * Coakley, B
EM: Bernard.Coakley@gi.alaska.edu
AF: Geophysical Institute, University of Alaska, Fairbanks, AK 99775 United States
AU: Kristoffersen, Y
EM: Yngve.Kristoffersen@geo.uib.no
AF: University of Bergen, Allegaten 41, Bergen, N-5007 Norway
AU: Edwards, M
EM: margo@soest.hawaii.edu
AF: Hawaii Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology University of Hawaii at Manoa 1680 East-West Road, POST 815, Honolulu, HI 96822 United States
AU: Johnson, L
EM: Gljgerg1@aol.com
AF: University of Alaska, School of Fisheries and Oceanography, Fairbanks, AK 99775 United States
AB: Anyone who has seen a weather map of the northern hemisphere understands that the Arctic Ocean has a climatic and oceanographic influence far beyond its limited geographic extent. This influence is not matched by our understanding of the basin history. For example, we do not know when sea ice first covered the Arctic Basin. The detailed geologic composition and history of major morphologic features, ridges, plateaus and margins is unknown. We could learn the coupled histories of the ocean basin and high latitude climate from the record preserved beneath the Arctic seafloor. Capturing this buried history requires a coordinated program of site surveying and drilling in the Arctic. The IPY is an opportune time to concentrate on this program. Over the past fifty years, we have learned the history of the continents from understanding the histories of the adjacent ocean basins. In the Arctic, we have inferred the history of the Amerasian basin from the limited stratigraphic record exposed on the Canadian and American continental margins. Large tectonic features, such as Lomonosov Ridge, the Alpha-Mendeleev Ridge, Makarov Basin, the Canada Basin and a number of continental margin features are virtually unknown. Reconstructions of the paleogeography of the northern hemisphere prior to Cenozoic times are hypothetical and can only be solved by deciphering the plate tectonic puzzle of the Mesozoic Arctic. Continental margins and sedimentary basins of polar and sub-polar areas contain large quantities of natural resources. The geological history of the northern hemisphere and the framework for the formation of such resources cannot be reconstructed properly if the nature and evolution of the basement of the Arctic Ocean is not determined by directly sampling basement rocks. The IPY offers an opportunity for a coordinated assault on the unsolved problems of the Arctic Ocean. The primary scientific goals during the IPY would be to understand: A) the climatic and paleo-oceanographic evolution of the Arctic region and its effects on global climate, the biosphere and the dynamics of the world ocean and atmosphere; and B) the nature and evolution of the major structural features of the Arctic Ocean Basin and circum-Arctic continental margins. NAD (Nansen Arctic Drilling Program) has suggested that the primary target areas in a first phase of drilling in the Arctic Ocean are the rises and plateaus. Here, the sediments are primarily biogenic fallout from the water masses and hemipelagic/pelagic clays. A later phase of drilling would give priority to the deep ocean basins where the water depth is 4000 m or greater and the sediment thicknesses are greater than 1 km. A major part of all plateaus and ridges would be accessible with a water depth capability of 1500 m except for Alpha Ridge. While the logistics of this work would be quite difficult, the drilling itself would present few challenges. From the available seismic reflection records it appears that 500m of penetration would reach basement on all plateaus and ridges as well as the major unconformity on the Lomonosov Ridge, which overlies a Mesozoic-aged passive margin, the European edge of the Mesozoic Arctic Ocean. This could be the most scientifically productive drilling ever undertaken (per meter).
DE: 3025 Marine seismics (0935)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 7218 Lithosphere and upper mantle
DE: 9315 Arctic region
SC: Cryosphere [C]
MN: 2003 Fall Meeting