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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 49 (1965)

Issue: 3. (March)

First Page: 359

Last Page: 359

Title: Direction of Crustal Movements Indicated by Earthquake Data: ABSTRACT

Author(s): William Stauder

Article Type: Meeting abstract


Two factors make desirable a re-evaluation of the inferences, drawn from seismic data, concerning the direction of crustal movements: 1) the revision of published fault plane solutions, occasioned by questions of the reliability of the solutions and by the recognition of bias in favor of strike-slip faulting; 2) the development of other methods, including the use of S waves and the application of surface waves in determining the directivity, dimensions, and initial phase of the source.

The most extensive seismic data pertinent to crustal movements are associated with the borders of the northern Pacific Ocean. Data from the smaller earthquakes (magnitude 6 3/4-7ΒΌ) indicate predominantly reverse or thrust faulting along fractures parallel to (e.g. Kamchatka-Kurile Island arc) or oblique to (e.g. Aleutian Islands) the trend of the tectonic features, with a lesser transcurrent component of motion. The principal compressive stress is nearly horizontal and is directed normal to the trend of the arc. The major earthquakes, on the other hand, especially as inferred from the data of surface waves, are predominantly strike slip. Fracturing extends for hundreds of kilometers and parallels oceanic deeps.

Examination of other regions, especially South America and regions of the southwest Pacific, permit inferences related directly to the underlying causes of crustal movement.

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Copyright 1997 American Association of Petroleum Geologists