Surface Wave Ray Tracing and Ms:Yield Determination in a Laterally Heterogeneous Earth

• Main Authors: Zeng, Yuehua, Teng, Ta-Liang, Aki, Keiiti
• Other Authors: UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF GEOLOGICAL SCIENCES
• Format: Text
• Language: English
• Published: 1989
• Subjects: Seismology; *ARCTIC OCEAN; *SEISMIC WAVES; *OCEAN BASINS; *EARTH MODELS; LOW VELOCITY; RAYLEIGH SCATTERING; YIELD; EARTH CRUST; HETEROGENEITY; INVERSION; EARTHQUAKES; EARTH(PLANET); RAY TRACING; OCEAN BOTTOM TOPOGRAPHY; DETERMINATION; ISLANDS; STRUCTURAL GEOLOGY; OCEAN RIDGES; ARCTIC REGIONS; RAYLEIGH WAVES; EARTH MANTLE; TECTONICS; SECONDARY WAVES; SEISMIC DATA; CANADA; SURFACE WAVES; VELOCITY; THICKNESS; GROUP VELOCITY; SEISMIC VELOCITY; NANSEN RIDGE; SHEAR WAVES; UPPER MANTLE; ALPHA RIDGE; PE61101E; WUAFGL7A10DACR; Arctic; Arctic Ocean; Canada; Makarov Basin; Alpha Ridge; alpha ridge; makarov basin
• Online Access: http://www.dtic.mil/docs/citations/ADA210241; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA210241

Pure path Rayleigh wave group velocities for 24 regional grids inside the Arctic have been obtained from 74 mixed path measurements. The vertical shear wave velocity structures under these 24 grids were then determined according to their pure path group velocity dispersion data. This result indicates that the crustal shear wave velocity in the Arctic region is generally lower than the world-wide average. In addition, a typical mid-ocean ridge structure was clearly shown under the Nansen Ridge. We also found an abnormally high upper mantle shear wave velocity under the Alpha Ridge and Makarov Basin, and low velocity beneath the Canadian Arctic Islands. In general, our inversion result agrees with the known tectonics in the Arctic region. To further check the validity of our result, we computed synthetic Rayleigh waves; a comparison with our observations shows very good agreement. Keywords: Seismic wave velocity; Ocean bottom topography; Tectonics; Rayleigh wave dispersion; Ocean basins; Earthquake seismic data; Earth crust thickness; Upper mantle; Structural geology; Surface waves; Ray tracing; Earth models. Sponsored in part by Defense Advanced Research Projects Agency.