Numerical Study on the Characteristics of AbyssalT-Wave Envelopes Controlled by Earthquake Source Parameters

Details

• Journal Title:
  Seismological Research Letters
• Personal Author:
  Yun, Sukyoung ; Lee, Won Sang ; Dziak, Robert P. ; Matsumoto, Haruyoshi
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; CIMRS (Cooperative Institute for Marine Resources Studies) ; PMEL (Pacific Marine Environmental Laboratory)
• Description:
  Hydroacoustics has been successfully applied to detect and locate small-to-intermediate submarine tectonic activities infrequently recorded in land-based seismic arrays. However, to extend the utilization of T waves to extract other important earthquake source parameters, such as source strength, the roles of earthquake focal mechanisms, and source depths in T-wave envelopes must be thoroughly understood. We performed 3D numerical modeling considering anisotropic source radiation and realistic scattering in the oceanic crust for two focal mechanisms (normal and strike-slip faults) and three depths (5, 10, and 15 km) to investigate the effect of source radiation and focal depth on abyssal T waves. By analyzing the synthetic T-wave envelopes, we showed that stronger SV-energy radiation from a normal-fault earthquake event generates higher-intensity T waves of the same source magnitude. The anisotropic source radiation of a double-couple source causes azimuthal changes in the shapes of T waves, and deeper earthquakes cause gentle-sloped envelopes; however, the slopes also vary with respect to the azimuths of receivers and focal mechanisms. Temporal changes in the slopes of T-wave envelopes of magmatic swarm events near Wordie Volcano, Bransfield Strait, Antarctic Peninsula, imply that the depth dependency can be utilized to determine relative depths for hydrothermal-vent events or sequenced earthquakes.
• Source:
  Seismological Research Letters, 93(4), 2189-2200
• DOI:
  https://doi.org/10.1785/0220210264
• ISSN:
  0895-0695 ; 1938-2057
• Format:
  PDF
• Publisher:
  Seismological Society of America (SSA)
• Document Type:
  Journal Article
• Rights Information:
  Accepted Manuscript
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:cec8de054b9b949a4c01aeaa395f6375ca7e7a7eff7fe72c4bb9e1e3d93ad55b35d3bc740acd452f280f045bae566f5c989b1a51a7caad745373f5190a55d8a0
• Download URL:
  https://repository.library.noaa.gov/view/noaa/66265/noaa_66265_DS1.pdf
• File Type:
  [PDF - 4.59 MB ]