17:15 〜 19:15
[SSS08-P07] Investigating Crustal Anisotropy in Volcanic Regions of Japan Using Shear Wave Splitting Analysis
キーワード：Shear wave splitting, Crustal anisotropy, Volcanic types, Japan
Shear wave splitting (SWS) analysis effectively investigates crustal anisotropy, providing valuable information on stress-oriented fractures, fluid dynamics, and magmatic activities beneath active volcanoes. Most studies have concentrated on individual volcanoes, with limited comparative research on different types of volcanoes. This study investigates the anisotropic properties of various volcanic types in Japan, utilizing SWS measurements to evaluate how geological and magmatic factors affect seismic anisotropy. We analyzed seismic data from local earthquakes recorded between 2005 and 2024, specifically examining events with magnitudes ranging from 1.5 to 5.5 and incidence angles of less than 35°. Initial findings show variations in delay times and fast shear wave orientations, implying unique anisotropic characteristics for each type of volcano. The noted anisotropy seems to be affected by a combination of regional stress patterns, fractures caused by magma, and structural factors within the volcanic structure. This research deepens our understanding of how various volcanic environments affect crustal anisotropy, offering important insights for seismic monitoring and volcanic hazard assessment. By examining anisotropic patterns across different volcanoes, this study enhances the broader framework of employing SWS analysis to monitor subsurface volcanic activity and stress evolution in regions of active tectonics.