Applications of SEASAT altimeter data in seismotectonic studies of the South-Central Pacific
Individual tracks of SEASAT altimeter data can be used effectively to identify significant bathymetric features in remote and unsurveyed ocean areas. It is especially important, for studies of oceanic seismicity, to identify correlation (or lack of correlation) between seismicity and bathymetric features. However, in many seismically active regions, bathymetric data are sparse or nonexistent. A typical example is the south-central Pacific, an area studied by Okal et al. (1980), who identified several sites of active intraplate seismicity. The purpose of the present paper is to demonstrate how SEASAT data can be used to aid in bathymetric and seismotectonic interpretation of this remote ocean area. We present two illustrations: (1) SEASAT observations of Macdonald seamount, a volcanically active seamount representing the youngest member in the Austral Island chain, and (2) SEASAT observation of a previously undiscovered fracture zone located at approximately 21.4 /sup 0/S and trending east-west between 232 /sup 0/E and 236 /sup 0/E. This fracture zone is located approximately 70 km to the south of a small region of active seismicity (96 events of magnitude greater than 2.7 from 1976 to 1980). On the basis of the demonstrated ability to observe active seamounts such as Macdonald and small fracture zones, we conclude that the observed seismicity in the region near 21 /sup 0/S, 233 /sup 0/E is due to intraplate stresses but is not associated with large-scale volcanism or with an active or fossil fracture zone.
- Research Organization:
- The Analytic Sciences Corporation, Reading, Massachusetts 01867
- OSTI ID:
- 6086486
- Journal Information:
- J. Geophys. Res.; (United States), Vol. 88:C3
- Country of Publication:
- United States
- Language:
- English
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