DOI: 10.1002/2016GL070175
论文题名: Dense lower crust elevates long-term earthquake rates in the New Madrid seismic zone
作者: Levandowski W. ; Boyd O.S. ; Ramirez-Guzmán L.
刊名: Geophysical Research Letters
ISSN: 0094-8751
EISSN: 1944-8482
出版年: 2016
卷: 43, 期: 16 起始页码: 8499
结束页码: 8510
语种: 英语
英文关键词: body forces
; finite element
; gravity
; intraplate seismicity
; New Madrid
; stress
Scopus关键词: Finite element method
; Geophysics
; Gravitation
; Seismology
; Stresses
; Tensors
; Body forces
; Finite element simulations
; Intraplate seismicity
; New Madrid
; New madrid seismic zones
; Regional stress field
; Seismic velocities
; Surrounding regions
; Earthquakes
英文摘要: Knowledge of the local state of stress is critical in appraising intraplate seismic hazard. Inverting earthquake moment tensors, we demonstrate that principal stress directions in the New Madrid seismic zone (NMSZ) differ significantly from those in the surrounding region. Faults in the NMSZ that are incompatible with slip in the regional stress field are favorably oriented relative to local stress. We jointly analyze seismic velocity, gravity, and topography to develop a 3-D crustal and upper mantle density model, revealing uniquely dense lower crust beneath the NMSZ. Finite element simulations then estimate the stress tensor due to gravitational body forces, which sums with regional stress. The anomalous lower crust both elevates gravity-derived stress at seismogenic depths in the NMSZ and rotates it to interfere more constructively with far-field stress, producing a regionally maximal deviatoric stress coincident with the highest concentration of modern seismicity. Moreover, predicted principal stress directions mirror variations (observed independently in moment tensors) at the NMSZ and across the region. ©2016. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84983772266&doi=10.1002%2f2016GL070175&partnerID=40&md5=f7bcaa3253e789bf849d12d7ca8a1c94
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/9714
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: U.S. Geological Survey Geologic Hazards Science Center, Golden, CO, United States
Recommended Citation:
Levandowski W.,Boyd O.S.,Ramirez-Guzmán L.. Dense lower crust elevates long-term earthquake rates in the New Madrid seismic zone[J]. Geophysical Research Letters,2016-01-01,43(16).