This proposal is a collaborative proposal from Principal Investigators at the University of Alaska-Fairbanks, Texas A & M, and University of Bergen. The Division of Ocean Sciences will contribute funding for future site selection surveys in the Arctic Ocean. Over the past few years, the Arctic Ocean has been revealed through the acquisition of new data by airplanes, icebreakers, and submarines. These data have been compiled into publicly available grids of bathymetry, gravity, and magnetic data that provide a basic regional description. This enormous international investment stems from the wide recognition that fundamental problems in the Earth Sciences, from paleoclimate and paleoceanographic issues to basic plate tectonics can be answered there. To unravel the region's history and gain a deeper understanding of the Arctic Ocean's evolution, it is necessary to image ridge structures and the accumulated Mesozoic and Cenozoic sediments with multi-channel seismic reflection data (MCS) and the deeper crust with seismic refraction data. Intellectual Merit - This project presents a program of high resolution MCS and seismic refraction data acquisition to be conducted along a transect across the Arctic basin during the summer of 2005 on the Healy with an Arctic adapted MCS system (200-300 meter streamer) and sonobuoys starting from Point Barrow, Alaska and ending near Svalbard, Norway. The transect will cross the Chukchi Borderland, the Nautilus Basin, the Mendeleev Ridge, the Alpha Ridge, the Makarov Basin, the Lomonosov Ridge, and the Gakkel Ridge. These new data will determine the internal structure of the ridges and plateaus that subdivide the basin, and will establish for the first time the stratigraphy of the intervening basins. Knowledge of this structure is required to test hypotheses regarding the of the basin and ridge history and the type and location of plate boundaries in the Amerasian Basin. The objectives go beyond a local understanding of the Arctic and bear directly on understanding the global plate tectonic circuit for the Mesozoic. National and International Cooperation - A group of U.S, Swedish, and Norwegian investigators will make major a cross-Arctic basin expedition in the summer, 2005. The Swedish icebreaker Oden will transit the basin, reproducing an oceanographic section collected in 1994. The USCG Healy will support solid earth and coring applications and will operate autonomously for about half of the expedition, meeting with Oden on the flanks of the Alpha Ridge to transit in tandem out of the basin. The project will receive substantial funding from the Norwegian Petroleum Directorate. During the combined programs, Healy will collect an unprecedented, integrated geophysical data set consisting of multi-beam swath bathymetry and sidescan, sub-bottom profiler, multi-channel seismic reflection and seismic refraction data. Broader Impacts - The focus of this research will be on the structure and stratigraphy of the Arctic Ocean, but the data will have uses beyond the work because an integrated data set collected from Healy will be the beginning of a site survey database for the Arctic Ocean. Thus, the first dedicated scientific drilling in the Arctic will take place on the Lomonosov Ridge during the summer of 2004. Collection of these new data will build on the efforts planned next summer, prepare for future scientific drilling operations in the Arctic Ocean and substantially increase international cooperation in Arctic Research. A number of students from both the US and Europe will participate in this cruise.
