Mantle flow at a slab edge: Seismic anisotropy in the Kamchatka region

• Main Authors: Peyton, V., Levin, V., Park, J., Brandon, M., Lees, J., Gordeev, E., Ozerov, A.
• Other Authors: College of Arts and Sciences, Department of Geological Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2001
• Subjects: Russian Federation; seismic anisotropy; plate boundary; Slab edge; mantle process; Shear wave birefringence; Pacific; Kamchatka Peninsula; Aleutian Island; Kamchatka
• Online Access: https://doi.org/10.17615/y2xd-0t12; https://cdr.lib.unc.edu/downloads/02871592v?file=thumbnail; https://cdr.lib.unc.edu/downloads/02871592v

The junction of the Aleutian Island and the Kamchatka peninsula defines a sharp turn in the boundary of the Pacific and North American plates, terminating the subduction zones of the northwest Pacific. The regional pattern of shear-wave birefringence near the junction indicates that trench-parallel strain follows the seismogenic Benioff zone, but rotates to trench-normal beyond the slab edge. Asthenospheric mantle is inferred to flow around and beneath the disrupted slab edge, and may influence the shallowing dip of the Benioff zone at the Aleutian junction.