Rupture process of large earthquakes in the northern Mexico subduction zone

The Cocos plate subducts beneath North America at the Mexico trench. The northernmost segment of this trench, between the Orozco and Rivera fracture zones, has ruptured in a sequence of five large earthquakes from 1973 to 1985; the Jan. 30, 1973 Colima event ( M s 7.5) at the northern end of the segment near Rivera fracture zone; the Mar. 14, 1979 Petatlan event ( M s 7.6) at the southern end of the segment on the Orozco fracture zone; the Oct. 25, 1981 Playa Azul event ( M s 7.3) in the middle of the Michoacan “gap”; the Sept. 19, 1985 Michoacan mainshock ( M s 8.1); and the Sept. 21, 1985 Michoacan aftershock ( M s 7.6) that reruptured part of the Petatlan zone. Body wave inversion for the rupture process of these earthquakes finds the best: earthquake depth; focal mechanism; overall source time function; and seismic moment, for each earthquake. In addition, we have determined spatial concentrations of seismic moment release for the Colima earthquake, and the Michoacan mainshock and aftershock. These spatial concentrations of slip are interpreted as asperities; and the resultant asperity distribution for Mexico is compared to other subduction zones. The body wave inversion technique also determines the Moment Tensor Rate Functions ; but there is no evidence for statistically significant changes in the moment tensor during rupture for any of the five earthquakes. An appendix describes the Moment Tensor Rate Functions methodology in detail.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43169/1/24_2004_Article_BF00875970.pd

Can a difference in molecular weights cause an eruption in a driven flow of self-organizing immiscible system?

Driven flow of a non-equilibrium non-conservative (NENC) system with a mixture of immiscible particles (A,B of molecular weight M A, M B) exhibits self-organizing patterns (segregation, phase-separation, etc.) in steady-state. The flow response (v) of mass flux density (j) to bias (H), $v=\partial j/\partial H$ in steady-state is found to be sensitive to molecular weight ratio (α=M B/M A). While the flux density (j) responds linearly to bias for both components (A, B) at α=1, onset of eruptive response occurs at extreme bias (H ↦ 1) at α > 1 where v ↦∞ for heavier (B) and v ↦- ∞ for lighter (A) constituents. Difference in molecular weights (M A, M B) is not only critical to eruptive flow but also in controlling the flow response prior to this crossover. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 200861.43.Bn Structural modeling: serial-addition models, computer simulation, 83.10.Rs Computer simulation of molecular and particle dynamics,