| Abstract: | Seven quadrilaterals, constructed at broadly distributed points on surface breaks within the Superstition Hills fault zone, were repeatedly remeasured after the pair of 24 November 1987 earthquakes to monitor the growing surface displacement. Changes in the dimensions of the quadrilaterals are recalculated to right-lateral and extensional components at millimeter resolution, and vertical components of change are resolved at 0.2mm precision. The displacement component data for four of the seven quadrilaterals record the complete fault movement with respect to an October 1986 base. The three-dimensional motion vectors all describe nearly linear trajectories throughout the observation period, and they indicate smooth shearing on their respective fault surfaces. The inclination of the shear surfaces is generally nearly vertical, except near the south end of the Superstition Hills fault zone where two strands dip northeastward at about 70??. Surface displacement on these strands is right reverse. Another kind of deformation, superimposed on the fault displacements, has been recorded at all quadrilateral sites. It consists of a northwest-southeast contraction or component of contraction that ranged from 0 to 0.1% of the quadrilateral lengths between November 1987 and April 1988. -from Authors |
| Genre: | Article |
| ProdID: | 70015668 |
| Citation Author: | Sharp, R. V.; Saxton, J. L. |
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| Citation End Page: | 389 |
| Citation Issue: | 2 |
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| Citation Language: | English |
| Citation Larger Work Title: | Bulletin - Seismological Society of America |
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| Citation Number Of Pages: | 14 |
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| Citation Search Results Text: | Three-dimensional records of surface displacement on the Superstition Hills fault zone associated with the earthquakes of 24 November 1987; 1989; Article; Journal; Bulletin - Seismological Society of America; Sharp, R. V.; Saxton, J. L. |
| Citation Start Page: | 376 |
| Citation Volume: | 79 |
| Citation Year: | 1989 |
| Type: | citation/reference |
| Text: | Three-dimensional records of surface displacement on the Superstition Hills fault zone associated with the earthquakes of 24 November 1987; 1989; Article; Journal; Bulletin - Seismological Society of America; Sharp, R. V.; Saxton, J. L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sun, 1 Jan 1989 00:00 -0600 |
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