| Abstract: | Postseismic deformation in the 5 years following the 1989 Loma Prieta earthquake has been measured with the Global Positioning System and precise leveling. Postearthquake velocities at distances greater than ???20 km from the coseismic rupture are not significantly different from those observed in the 20 years prior to the earthquake. However, velocities at stations within ???20 km of the rupture exceed preearthquake rates and exhibit unanticipated contraction normal to the strike of the San Andreas fault system. A combination of forward modeling and nonlinear optimization suggests that the observed postseismic deformations were caused by aseismic oblique reverse slip averaging 2.9 cm/yr on the San Andreas fault and/or the Loma Prieta rupture zone and 2.4 cm/yr reverse slip along a buried fault within the Foothills thrust belt. The best fitting sources of postseismic deformation are all located at depths of less than 15 km. We find no evidence for accelerated flow or shear below the Loma Prieta rupture in the first 5 years following the earthquake. The inferred postseismic slip is likely to have been caused by the coseismic stress change updip of the 1989 rupture. Copyright 1997 by the American Geophysical Union. |
| Genre: | Article |
| ProdID: | 70019488 |
| Citation Author: | Burgmann, R.; Segall, P.; Lisowski, M.; Svarc, J. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 4955 |
| Citation Issue: | B3 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Journal of Geophysical Research B: Solid Earth |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 23 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Postseismic strain following the 1989 Loma Prieta earthquake from GPS and leveling measurements; 1997; Article; Journal; Journal of Geophysical Research B: Solid Earth; Burgmann, R.; Segall, P.; Lisowski, M.; Svarc, J. |
| Citation Start Page: | 4933 |
| Citation Volume: | 102 |
| Citation Year: | 1997 |
| Type: | citation/reference |
| Text: | Postseismic strain following the 1989 Loma Prieta earthquake from GPS and leveling measurements; 1997; Article; Journal; Journal of Geophysical Research B: Solid Earth; Burgmann, R.; Segall, P.; Lisowski, M.; Svarc, J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 1 Jan 1997 00:00 -0600 |
| Publisher: | |
