Connotea
CiteULike
del.ico.us
BibSonomyAbstract
GRACE gravity evidence for an impact basin in Wilkes Land, Antarctica
School of Earth Sciences, Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA
Laboratory for Space Geodesy and Remote Sensing Research, Ohio State University, Columbus, Ohio 43210, USA
Laboratory for Space Geodesy and Remote Sensing Research, Ohio State University, Columbus, Ohio 43210, USA
Department of Engineering Technology, New Jersey Institute of Technology, 2101 Guttenberg Information Technologies Center, University Heights, Newark, New Jersey 07102, USA
School of Earth Sciences, Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA
Laboratory for Space Geodesy and Remote Sensing Research, Ohio State University, Columbus, Ohio 43210, USA
School of Earth Sciences, Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA
Laboratory for Space Geodesy and Remote Sensing Research, Ohio State University, Columbus, Ohio 43210, USA
Department of Geoenvironmental Science, Kongju National University, 182 Shinkwan-dong, Gongju, ChungNam-do, 314-701, South Korea
Goddard Earth Sciences and Technology Center, University of Maryland Baltimore County, 5523 Research Park Drive, Suite 320, Baltimore, Maryland, 21228 USA
School of Earth Sciences, Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA
Department of Geomatics Engineering, University of Calgary, Calgary, Alberta T2N 1N4, Canada
Department of Antarctic Geology, VNIIOkeangeologia, 1 Angliysky Avenue, St. Petersburg, 190121, Russia
School of Earth Sciences, Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA
Department of Geosciences, Universidad Nacional de Colombia, Carrera 30 No 45-03 Z.P. 06, Bogotá, Colombia
School of Earth Sciences, Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA
Equipe De Géomagnétisme, IPGS, CNRS, 2 place Jussieu, tour 14, F-75005 Paris, France
New details on the east Antarctic gravity field from the Gravity Recovery and Climate Experiment (GRACE) mission reveal a prominent positive free-air gravity anomaly over a roughly 500-km diameter subglacial basin centered on (70°S, 120°E) in north central Wilkes Land. This regional inverse correlation between topography and gravity is quantitatively consistent with thinned crust from a giant meteorite impact underlain by an isostatically disturbed mantle plug. The inferred impact crater is nearly three times the size of the Chicxulub crater and presumably formed before the Cretaceous formation of the east Antarctic coast that cuts the projected ring faults. It extensively thinned and disrupted the Wilkes Land crust where the Kerguelen hot spot and Gondwana rifting developed but left the adjacent Australian block relatively undisturbed. The micrometeorite and fossil evidence suggests that the impact may have occurred at the beginning of the greatest extinction of life on Earth at ∼260 Ma when the Siberian Traps were effectively antipodal to it. Antipodal volcanism is common to large impact craters of the Moon and Mars and may also account for the antipodal relationships of essentially half of the Earth's large igneous provinces and hot spots. Thus, the impact may have triggered the “Great Dying” at the end of the Permian and contributed to the development of the hot spot that produced the Siberian Traps and now may underlie Iceland. The glacial ice up to a few kilometers thick that has covered the crater for the past 30–40 Ma poses formidable difficulties to sampling the subglacial geology. Thus, the most expedient and viable test of the prospective crater is to survey it for relevant airborne gravity and magnetic anomalies.
Received 2 July 2008; accepted 13 January 2009; published 25 February 2009.
Citation: (2009), GRACE gravity evidence for an impact basin in Wilkes Land, Antarctica, Geochem. Geophys. Geosyst., 10, Q02014, doi:10.1029/2008GC002149.
Cited By