Record details

    Is the seismic moment tensor ambiguous at a material interface?
    Vavryčuk, Václav
Publication type
    článek v odborném periodiku
Source title - serial
    Geophysical Journal International
    Roč. 194, č. 1
    s. 395-400
    Projekt: FP7 Consortium Project AIM 230669, European Commission, XE3cav_un_auth*0301878
    Projekt: GAP210/12/1491, GA ČR, CZ3cav_un_auth*0285048
    Rozsah: 6 s. : P
Subject category
    body waves
    dynamics and mechanics of faulting
    earthquake dynamics
    earthquake source observations
    seismic anisotropy
Abstract (in english)
   The moment tensors are unique and describe the body force equivalents of rupture processes in any medium including faulting at a material interface, defined as the contact of two media with non-zero velocity or density contrasts. From a practical point of view, however, the moment tensor inversion of sources near or at a material interface is more involved than if the medium is smooth in the source area. First, the moment tensors of sources characterized by the same displacement discontinuity display jumps when the source crosses the interface. Consequently, the moment tensors become sensitive to the source location. If the source lies near the interface, the location into an incorrect half-space can introduce errors in the moment tensor. Second, if the source lies at the material interface, some of the spatial derivatives of the Green's function are, in general, discontinuous and the radiated wave field must be calculated using a generalized representation theorem.
   Third, the moment tensors are functions of averaged elastic parameters known from effective medium theory.
    AV ČR Brno, Geofyzikální ústav
Contributor code
    AV ČR, GFÚ
Source format
Import date
    23. 10. 2014