Deformation following the 1994 Northridge Earthquake (M=6.7), Southern California

• Published in: Geophysical research letters Vol. 25; no. 14; pp. 2725 - 2728
• Main Authors: Savage, J. C., Svarc, J. L., Prescott, W. H., Hudnut, K. W.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 15.07.1998; American Geophysical Union
• Subjects: Earth sciences; Earth, ocean, space; Earthquakes, seismology; Exact sciences and technology; Internal geophysics; Solid-earth geophysics, tectonophysics, gravimetry; San Andreas Fault; Southern California; California; United States; satellite methods; ground motion; velocity; epicenters; earthquakes; North America; rupture; Global Positioning System; tectonic blocks; positioning; displacements; fault displacements; deformation; geodesy
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/98GL02058

Following the 1994 Mw=6.7 Northridge earthquake, a 65‐km‐long, north‐south array of 11 geodetic monuments was established across the rupture. The array was surveyed with GPS ten times in the 4.25 yr after the earthquake. Although there is evidence for modest nonlinear postseismic relaxation in the first few weeks after the Northridge earthquake, the deformation in the subsequent four years can be adequately described by constant station velocities. The observed S70°E velocity components are consistent with the deformation expected from steady strain accumulation on the San Andreas fault. The N20°E velocity components indicate that the southern Northridge fault block is moving almost as a unit N20°E with repect to the northern fault block, the motion being accommodated by a zone of convergence (width 20 km) at the north end of the Northridge rupture.