Record details

    Microearthquake mechanism from wave amplitudes recorded by a close-to-surface seismic array at Ocnele Mari, Romania
    Jechumtálová, Zuzana
    Šílený, Jan
    Trifu, C.-I.
Publication type
    článek v odborném periodiku
Source title - serial
    Geophysical Journal International
    Roč. 197, č. 3
    s. 1608-1626
    Projekt: FP7 Consortium Project AIM 230669, European Commission, XE3cav_un_auth*0301878
    Projekt: GAP210/10/1728, GA ČR3cav_un_auth*0263509
    Projekt: GAP210/12/2235, GA ČR3cav_un_auth*0284894
    Rozsah: 19 s.
Subject category
    computational seismology
    earthquake source observation
    fractures and faults
    inverse theory
    mechanic, theory, and modelling
Abstract (in english)
   The resolution of event mechanism is investigated in terms of the unconstrained moment tensor (MT) source model and the shear-tensile crack (STC) source model representing a slip along the fault with an off-plane component. Data are simulated as recorded by the actual seismic array installed at Ocnele Mari (Romania), where sensors are placed in shallow boreholes. Noise is included as superimposed on synthetic data, and the analysis explores how the results are influenced (i) by data recorded by the complete seismic array compared to that provided by the subarray of surface sensors, (ii) by using three- or one-component sensors and (iii) by inverting P- and S-wave amplitudes versus P-wave amplitudes only. The orientation of the pure shear fracture component is resolved almost always well. On the other hand, the noise increase distorts the non-double-couple components (non-DC) of the MT unless a highquality data set is available.
   The STC source model yields considerably less spurious non-shear fracture components. Incorporating recordings at deeper sensors in addition to those obtained from the surface ones allows for the processing of noisier data.
    AV ČR Brno, Geofyzikální ústav
Contributor code
    AV ČR, GFÚ
Source format
Import date
    23. 10. 2014