Show simple item record Johnson, Catherine L. Constable, Catherine G. Tauxe, Lisa Barendregt, René W. Brown, Laurie L. Coe, Rob Gans, Phil Layer, Paul Mejia, Vicky Opdyke, Neil D. Singer, Brad Staudigel, Hubert Stone, David 2015-06-12T17:53:00Z 2015-06-12T17:53:00Z 2015-06-12
dc.description Sherpa Romeo green journal (pre or post print only) en_US
dc.description.abstract We present a synthesis of paleomagnetic directional data collected from 873 lava flows at 17 different locations under the collaborative Time Averaged geomagnetic Field Initiative (TAFI). The data range from 05 Ma in age, and provide new high quality data with improved spatial coverage. Data quality at each site is measured using k, the best estimate of the Fisherian precision parameter, and its influence on inclination anomaly and VGP dispersion is evaluated by systematically excluding data with successively higher values of k. When combined with regional compilations from NW USA, SW USA, Japan, New Zealand, Hawaii, Mexico, S. Pacific and the Indian Ocean, a data set of 2283 pairs of declination and inclination data, with k>100, and VGP latitudes greater than 45 is obtained. This is a more than 7fold increase over similar quality data in the existing Global Paleomagnetic Database (GPMDB). The new data set spans 78 S to 53 N, and has sufficient temporal and spatial sampling to allow characterization of latitudinal variations in the timeaveraged field (TAF) and paleosecular variation (PSV) for the Brunhes and Matuyama epochs, and for the 0–5 Myr interval combined. PSV, as measured by dispersion of virtual geomagnetic poles, shows less latitudinal variation than predicted by current statistical PSV models. Variation of inclination anomaly with latitude is assessed using 2parameter zonal TAF models – these have axial quadrupole contributions of 2% – 4% of the axial dipole term, and axial octupole contributions of 3% – 5%. Approximately 2% of the octupole signature is likely the result of bias incurred by averaging unit vectors. The new data set provides significant improvement over previous compilations, and can contribute to a new generation of global paleomagnetic field models. en_US
dc.language.iso en_CA en_US
dc.subject Paleomagnetic directional data en_US
dc.subject Lava flows en_US
dc.subject Time-Averaged Field Investigations (TAFI) en_US
dc.subject Geomagnetic field
dc.subject 0-5 Ma
dc.title Recent investigations of the 0-5 geomagnetic field recorded by lava flows en_US
dc.type Article en_US
dc.publisher.faculty Arts and Science en_US
dc.publisher.department Department of Geography en_US
dc.description.peer-review Yes en_US
dc.publisher.institution University of British Columbia en_US
dc.publisher.institution Scripps Institution of Oceanography, University of California en_US
dc.publisher.institution University of Lethbridge en_US
dc.publisher.institution University of Massachussetts en_US
dc.publisher.institution University of California, Santa Cruz en_US
dc.publisher.institution University of California, Santa Barbara en_US
dc.publisher.institution University of Alaska en_US
dc.publisher.institution University of Florida en_US
dc.publisher.institution University of Wisconsin en_US

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