HR: 12:05h
AN: U32A-08 INVITED     [Abstracts]
TI: A Comparison of Geodetic and Paleomagnetic Estimates of Block Rotation Rates in Deforming Zones
AU: * McCaffrey, R
EM: mccafr@rpi.edu
AF: Rensselaer Polytechnic Institute, Dept. of Earth & Environmental Sciences, Troy, NY 12180 United States
AU: Wallace, L M
EM: l.wallace@gns.cri.nz
AF: Institute of Geological and Nuclear Sciences, IGNS, Lower Hutt, 00000 New Zealand
AB: Rotations of crustal blocks estimated by paleomagnetic declination anomalies and by modern geodetic (GPS) data sample vastly different time spans. We are estimating modern-day vertical axis rotations of crustal blocks from several deforming zones by inversion of GPS velocities. In general these decade-scale rotation rates compare very well to several-million-year-scale paleomagnetic rotation rates. In the US Pacific Northwest, even a fine scale feature such as the rapid landward decrease in rotation rate evident in 12-15Ma basalt flows is recorded in 10-years of GPS data. However, in some cases, notably in the California Transverse Ranges, rapid rotations evident in paleomagnetic data do not appear to be continuing today. We will discuss our results in New Zealand, Papua New Guinea, the western US, and other parts of the world.
DE: 8107 Continental neotectonics
DE: 8157 Plate motions--past (3040)
DE: 1525 Paleomagnetism applied to tectonics (regional, global)
SC: Union [U]
MN: 2004 AGU Fall Meeting