Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/9361
Title: Subsea permafrost in Harrison Bay, Alaska : an interpretation from seismic data
Authors: United States. National Oceanic and Atmospheric Administration.
United States. Bureau of Land Management.
Outer Continental Shelf Environmental Assessment Program.
Neave, K. G.
Sellmann, P. V. (Paul V.)
Keywords: Alaska-Seismology
Seismic detection
Beaufort Sea-Seismology
Seismic reflection
Permafrost
Frozen ground
Seismic signatures
Seismic data
Seismology
Publisher: Cold Regions Research and Engineering Laboratory (U.S.)
Engineer Research and Development Center (U.S.)
Series/Report no.: CRREL report ; 82-24.
Description: CRREL Report
Abstract: Velocity data derived from petroleum industry seismic records from Harrison Bay show that high-velocity material (> 2 km/s) interpreted to be ice-bonded permafrost is common. In the eastern part of the bay, the depth to high velocity material increases and velocity decreases in an orderly manner with increasing distance from shore until the layer is no longer apparent. The western part of the bay is less orderly, possibly reflecting a different geological and thermal history. This western part may be an inundated section of the low coastal plain characterized by the region north of Teshekpuk Lake, and could have contained deep thaw lakes, creating low velocity zones. Along some seismic lines, the high-velocity material extends approximately 25 km offshore. Two anomalies have been found which could be associated with rapidly degrading permafrost. One is strong attenuation, which was interpreted as an indication of gas in the shallow deposits. The other is the presence of considerable seismic noise, including identifiable small seismic events. The origin of this noise has not been positively established, and it is proposed that it may indicate that some movement is occurring in the sediments due to thaw.
URI: http://hdl.handle.net/11681/9361
Appears in Collections:CRREL Report

Files in This Item:
File Description SizeFormat 
CR-82-24.pdf2.24 MBAdobe PDFThumbnail
View/Open