EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Scherwath et al. 2003
Scherwath, M., Stern, T., Davey, F., Okaya, D., Holbrook, W.S., Davies, R. and Kleffmann, S. (2003). Lithospheric structure across oblique continental collision in New Zealand from wide-angle P wave modeling. Journal of Geophysical Research 108: doi: 10.1029/2002JB002286. issn: 0148-0227.

Oblique convergence between the Australian and Pacific plates in South Island, New Zealand, has resulted in crustal thickening and distributed deformation within both plates. We measure this thickening and image the deformation with seismic wide-angle data along a 600 km long transect that spans the plate boundary. P wave arrival times from 34,000 rays are used to construct a two-dimensional model for seismic velocity with depth. Crustal velocities average 6.1 and 6.2 (¿0.23) km/s for the Australian and Pacific sides of the boundary, respectively. Upper mantle velocities average 8.1 (¿0.25) km/s. Distributed deformation is indicated by the following observations: a reduction in upper crustal and midcrustal velocities by 4% west of the plate boundary, ascribed to flexural bending stresses; a velocity reduction of 8% immediately east of the Alpine fault, linked to high pore fluid pressures; 17 km of crustal thickening to form a 44(¿1.4) km deep crustal root that is offset 10--20 km SE of the highest mountains; a velocity reversal below the midcrust in the eastern part of the crustal root, caused either by heating or an artifact from seismic anisotropy; strong thickening of a 7.0(¿0.4) km/s fast lower crust within the crustal root; and a low-velocity zone in the Australian upper mantle due to sampling the slow orientation of upper mantle anisotropy.

BACKGROUND DATA FILES

Abstract

Keywords
Seismology, Lithosphere and upper mantle, Tectonophysics, Continental tectonics--general, Tectonophysics, Earth's interior--composition and state, Tectonophysics, Plate boundary--general, Tectonophysics, Tomography
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit