Seismicity and stress rotation in a granular model of the brittle crust

@article{ScottNature1996, abstract = {THE basic mechanical process responsible for earthquakes and faulting is not known. The intuitive notion of frictional slip on faults between elastic crustal blocks cannot be reconciled with laboratory measurements of the strength of rocks1, field observations of heat flow2,3 and stress orientation4 around the San Andreas fault in California, and seismological estimates of the energy radiated by earthquakes5. The weakening of large faults by elevated pore-fluid pressure6 has been suggested as one solution to this paradox, but places severe constraints on the hydrological conditions of the faults concerned. Here I propose an alternative model for earthquake mechanics, in which the crust is treated as a system of many interlocking blocks divided by many faults7. The model combines this random granular structure with simple, deterministic mechanical interactions. Numerical simulations of the deformation of an aggregate of rough grains under compressive stress show earthquake-like elastodynamic failures without frictional heat production, and substantial rotation of stresses across shear zones, which mimics field observations. There remain problems of scale in comparing these simulations with nature, but a seismological test of the model may be possible.}, author = {Scott, David R. }, citeulike-article-id = {2383557}, doi = {10.1038/381592a0}, editor = {Nature}, journal = {Nature}, keywords = {earth\_crust, granular, qual, qualifier, tectonic\_plates}, month = {June}, pages = {592--595}, posted-at = {2008-02-15 02:55:15}, priority = {2}, title = {Seismicity and stress rotation in a granular model of the brittle crust}, url = {http://www.nature.com.proxy.library.emory.edu/nature/journal/v381/n6583/abs/381592a0.html}, volume = {381}, year = {1996} }

TY - JOUR ID - ScottNature1996 L3 - citeulike-article-id:2383557 TI - Seismicity and stress rotation in a granular model of the brittle crust JF - Nature VL - 381 SP - 592 EP - 595 N2 - THE basic mechanical process responsible for earthquakes and faulting is not known. The intuitive notion of frictional slip on faults between elastic crustal blocks cannot be reconciled with laboratory measurements of the strength of rocks1, field observations of heat flow2,3 and stress orientation4 around the San Andreas fault in California, and seismological estimates of the energy radiated by earthquakes5. The weakening of large faults by elevated pore-fluid pressure6 has been suggested as one solution to this paradox, but places severe constraints on the hydrological conditions of the faults concerned. Here I propose an alternative model for earthquake mechanics, in which the crust is treated as a system of many interlocking blocks divided by many faults7. The model combines this random granular structure with simple, deterministic mechanical interactions. Numerical simulations of the deformation of an aggregate of rough grains under compressive stress show earthquake-like elastodynamic failures without frictional heat production, and substantial rotation of stresses across shear zones, which mimics field observations. There remain problems of scale in comparing these simulations with nature, but a seismological test of the model may be possible. KW - earth_crust KW - granular KW - qual KW - qualifier KW - tectonic_plates AU - Scott, David A2 - Nature PY - 1996/06// UR - http://www.nature.com.proxy.library.emory.edu/nature/journal/v381/n6583/abs/381592a0.html ER -