Response of desert pavement to seismic shaking , Hector Mine earthquake , California , 1999
نویسنده
چکیده
[1] The October 1999 Mw 7.1 Hector Mine earthquake in the Mojave Desert, California, generated characteristic surface disturbances on nearby desert pavements. These disturbances included (1) zones of wholesale gravel displacement interspersed with zones of intact pavement, (2) displaced and rotated cobbles, (3) moats around loosened, embedded boulders, (4) filling of abandoned cobble sockets, boulder moats, and other depressions with gravel, and (5) formation of narrow, subparallel, linear strips of exposed fine-grained subpavement matrix (matrix lineations). Clasts displaced from matrix lineations and from cobble sockets tended to move downslope. Sharp boundaries of matrix lineations and slope-controlled displacement directions on slopes of only a few degrees indicated that clasts remained close to the pavement surface during shaking. The regular, few decimeter spacing of matrix lineations suggests the presence of standing waves during seismic shaking. Boulder moats probably have good preservation potential and, at some desert pavement locations, might provide information on paleoseismic shaking. Although readily produced by coseismic shaking, displaced cobbles are unreliable indicators of past earthquake activity because of potential multiple origins. For an assumed earthquake recurrence interval of 10 ka, seismically driven sediment fluxes similar to those generated by the Hector Mine earthquake at the Lavic Siding pavement study site may be marginally competitive with aseismic smoothing mechanisms driven by bioturbation, rainbeat, and wash. For a 1 ka recurrence interval, seismic smoothing is likely to play a significant role in pavement evolution.
منابع مشابه
TriMan: An interactive tool for modeling earthquakes, with applications to the 1992 Landers and 1999 Hector Mine, California earthquakes
Introduction......................................................................................................................... 1 TriMan software package ................................................................................................... 2 The numeric model ......................................................................................................... 3 Inverse m...
متن کاملDeformation on nearby faults induced by the 1999 Hector Mine earthquake.
Interferometric Synthetic Aperture Radar observations of surface deformation due to the 1999 Hector Mine earthquake reveal motion on several nearby faults of the eastern California shear zone. We document both vertical and horizontal displacements of several millimeters to several centimeters across kilometer-wide zones centered on pre-existing faults. Portions of some faults experienced retrog...
متن کاملThe complete (3-D) surface displacement field in the epicentral area of the 1999 Mw7.1 Hector Mine earthquake, California, from space geodetic observations
We use Interferometric Synthetic Aperture Radar (InSAR) data to derive continuous maps for three orthogonal components of the co-seismic surface displacement field due to the 1999 Mw7.1 Hector Mine earthquake in southern California. Vertical and horizontal displacements are both predominantly antisymmetric with respect to the fault plane, consistent with predictions of linear elastic models of ...
متن کاملOn the reported ionospheric precursor of the 1999 Hector Mine, California earthquake
[1] Using Global Positioning System (GPS) data from sites near the 16 Oct. 1999 Hector Mine, California earthquake, Pulinets et al. (2007) identified anomalous changes in the ionospheric total electron content (TEC) starting one week prior to the earthquake. Pulinets (2007) suggested that precursory phenomena of this type could be useful for predicting earthquakes. On the other hand, and in a s...
متن کامل