Energy Release of the 2013 Mw 8.3 Sea of Okhotsk Earthquake and Deep Slab Stress Heterogeneity

• Published in: Science (American Association for the Advancement of Science) Vol. 341; no. 6152; pp. 1380 - 1384
• Main Authors: LINGLING YE, LAY, Thorne, KANAMORI, Hiroo, KOPER, Keith D
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 20.09.2013; The American Association for the Advancement of Science
• Subjects: Earth; Earth sciences; Earth, ocean, space; Earthquake damage; Earthquakes; Earthquakes, seismology; Exact sciences and technology; Fracture toughness; Heterogeneity; Internal geophysics; Nucleation; Oceanic analysis; Sea of Okhotsk; Seismic phenomena; Slabs; Stress analysis; Stresses; Tectonics. Structural geology. Plate tectonics; Okhotsk Sea; West Pacific; Pacific Ocean; INW, Okhotsk Sea; stress; models; efficiency; seismic energy; lithosphere; P-waves; velocity; mainshocks; earthquakes; heterogeneity; rupture; Pacific Plate; subduction; aftershocks; temperature; magnitude; oceanic crust
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1242032

Delineating Deep Faults. Most large, damaging earthquakes initiate in Earth's crust where friction and brittle fracture control the release of energy. Strong earthquakes can occur in the mantle too, but their rupture dynamics are difficult to determine because higher temperatures and pressures play a more important role. Ye et al. (p. 1380) analyzed seismic P waves generated by the 2013 Mw 8.3 Sea of Okhotsk earthquake-the largest deep earthquake recorded to date-and its associated aftershocks. The earthquake ruptured along a fault over 180-kilometer-long and structural heterogeneity resulted in a massive release of stress from the subducting slab. In a set of complementary laboratory deformation experiments, Schubnel et al. (p. 1377) simulated the nucleation of acoustic emission events that resemble deep earthquakes. These events are caused by an instantaneous phase transition from olivine to spinel, which would occur at the same depth and result in large stress releases observed for other deep earthquakes.