T172 Virtual Tectonics

Tuesday, 2 November 2010
8:00 AM - 12:00 PM
Hall E

3D VISUALIZATION OF ARCTIC OCEAN MULTIBEAM BATHYMETRIC DATA AND THE CONSTRAINTS IT OFFERS TO TECTONIC RECONSTRUCTION MODELS

Paper number: T172-3
Program: Technical Sessions
Time: 8:30 AM – 8:45 AM

Authors

Abstract

Our understanding of the tectonic development of the Amerasia Basin, Arctic Ocean, is still in a nascent stage due to the lack of well-defined magnetic anomalies and the difficulties associated with traditional geologic and geophysical data collection in ice-covered water. In recent years multibeam bathymetric data have been collected as part of the U.S. and Canada’s Extended Continental Shelf projects to support claims under Article 76 of the United Nation’s Convention for Law of the Sea. The utilization of 3D visualization programs such as IVS Fledermaus (Mayer et al., 2000) as well as a shipboard geospatial Mapserver (Roberts et al., 2007) have been integral aboard ship in the Arctic Ocean during data collection cruises, as well as for the post-cruise interpretation of multibeam bathymetric and seismic data. These data can offer constraint on the tectonic evolution of the Amerasia Basin and provide unprecedented new detail on the geomorphology of the intra-basinal ridges or highs that are common throughout most of the Amerasia Basin.

Aboard the icebreaker USCGC Healy, 3D visualization of multibeam bathymetric data is used to choose sample collection sites and has allowed for surgical precision of both dredging and coring targets. Dredged rock samples from outcrops along steep slopes within the Amerasia Basin during the 2008 and 2009 data collection cruises, supply some of the first ground-truthed information about the crustal affinities of bathymetric highs within the Amerasia Basin.

The combination of multibeam bathymetry and seismic data in three dimensions has aided in the delineation of normal fault systems that can then be used to determine rift directions and provide constraint on tectonic reconstructions of the Arctic. The geometry of rift-related normal faults imaged with multibeam and seismic data, indicate a consistent regional fault pattern. This rift fabric represents normal fault systems that utilized accommodation zones and transfer faults to facilitate the amalgamation of major normal faults. This type of geometry has been described in other continental rifted regions like the Basin and Range of the U.S. and the East African Rift. 3D visualization programs have been essential to our understanding of the Arctic Ocean seafloor and the tectonic implications of the structures found there.