TY - JOUR

T1 - Numerical modelling of seismic waves from earthquakes recorded by a network on ice floes

AU - Serdyukov, Aleksander

AU - Koulakov, Ivan

AU - Yablokov, Aleksander

PY - 2019/7/1

Y1 - 2019/7/1

N2 - A promising way to perform seismological studies in the Arctic region is deploying seismic stations on ice floes. The pioneering works by the AlfredWegener Institute Bremerhaven have demonstrated the efficiency of such floating networks to explore local and regional seismicity and to build 3-D seismic models. However, problems remain, related to the identification of different types of seismicwaves, particularly Swaves. Here,we perform2-D and 3-D numerical simulations of seismic waves emitted by an earthquake to explore the possibility of recording different phases on the sea surface. We use different types of simple shear source models, namely strike-slip, vertical displacement and normal faults. In the calculated wave field, we obtain three major types of seismic waves recorded on the sea surface-Pw, Sw and SPw (w denotes an acoustic wave in the water layer)-and numerous multiple waves. The clarity of the recorded phases strongly depends on the type of wave, source mechanism, epicentral distance, thickness of the water layer and depth of the source. For example, the Pw phase is clearest for the strike-slip mechanism, less clear for the normal fault and almost invisible for the vertical displacement. The Sw phase is observable in all of these cases; however, it can be confused with the SPw phase that arrives earlier. In addition, at some distances, the Sw wave interferes with the multiple Pw2 wave and therefore is hardly detectable. In summary, the numerical simulations in a model with a water layer have demonstrated several non-obvious features of wave propagation that should be taken into account when analysing experimental data recorded on ice floes.

AB - A promising way to perform seismological studies in the Arctic region is deploying seismic stations on ice floes. The pioneering works by the AlfredWegener Institute Bremerhaven have demonstrated the efficiency of such floating networks to explore local and regional seismicity and to build 3-D seismic models. However, problems remain, related to the identification of different types of seismicwaves, particularly Swaves. Here,we perform2-D and 3-D numerical simulations of seismic waves emitted by an earthquake to explore the possibility of recording different phases on the sea surface. We use different types of simple shear source models, namely strike-slip, vertical displacement and normal faults. In the calculated wave field, we obtain three major types of seismic waves recorded on the sea surface-Pw, Sw and SPw (w denotes an acoustic wave in the water layer)-and numerous multiple waves. The clarity of the recorded phases strongly depends on the type of wave, source mechanism, epicentral distance, thickness of the water layer and depth of the source. For example, the Pw phase is clearest for the strike-slip mechanism, less clear for the normal fault and almost invisible for the vertical displacement. The Sw phase is observable in all of these cases; however, it can be confused with the SPw phase that arrives earlier. In addition, at some distances, the Sw wave interferes with the multiple Pw2 wave and therefore is hardly detectable. In summary, the numerical simulations in a model with a water layer have demonstrated several non-obvious features of wave propagation that should be taken into account when analysing experimental data recorded on ice floes.

KW - Computational seismology

KW - Earthquake dynamics

KW - Seismic tomography

KW - Theoretical seismology

KW - Wave propagation

KW - SPREADING GAKKEL RIDGE

KW - UPPER-MANTLE

KW - MEDIA

KW - FDM SIMULATION

KW - ARCTIC-OCEAN

KW - PROPAGATION

UR - http://www.scopus.com/inward/record.url?scp=85067680335&partnerID=8YFLogxK

U2 - 10.1093/gji/ggz148

DO - 10.1093/gji/ggz148

M3 - Article

AN - SCOPUS:85067680335

VL - 218

SP - 74

EP - 87

JO - Geophysical Journal International

JF - Geophysical Journal International

SN - 0956-540X

IS - 1

ER -