DOI: 10.1016/j.epsl.2017.12.044
Scopus记录号: 2-s2.0-85044605549
论文题名: Evidence of displacement-driven maturation along the San Cristobal Trough transform plate boundary
作者: Neely J.S. ; Furlong K.P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 485 起始页码: 88
结束页码: 98
语种: 英语
英文关键词: plate tearing
; San Cristobal Trough
; transform plate boundary development
Scopus关键词: Earthquakes
; Coulomb failure stress
; Development process
; Key characteristics
; San Cristobal Trough
; Strain localizations
; Strike-slip earthquakes
; Subduction-transform edge propagator
; Transform plate boundary
; Faulting
英文摘要: The San Cristobal Trough (SCT), formed by the tearing of the Australia plate as it subducts under the Pacific plate near the Solomon Islands, provides an opportunity to study the transform boundary development process. Recent seismicity (2013–2016) along the 280 km long SCT, known as a Subduction-Transform Edge Propagator (STEP) fault, highlights the tearing process and ongoing development of the plate boundary. The region's earthquakes reveal two key characteristics. First, earthquakes at the western terminus of the SCT, which we interpret to indicate the Australia plate tearing, display disparate fault geometries. These events demonstrate that plate tearing is accommodated via multiple intersecting planes rather than a single through-going fault. Second, the SCT hosts sequences of Mw ∼7 strike-slip earthquakes that migrate westward through a rapid succession of events. Sequences in 1993 and 2015 both began along the eastern SCT and propagated west, but neither progression ruptured into or nucleated a large earthquake within the region near the tear. Utilizing b-value and Coulomb Failure Stress analyses, we examine these along-strike variations in the SCT's seismicity. b-Values are highest along the youngest, western end of the SCT and decrease with increasing distance from the tear. This trend may reflect increasing strain localization with increasing displacement. Coulomb Failure Stress analyses indicate that the stress conditions were conducive to continued western propagation of the 1993 and 2015 sequences suggesting that the unruptured western SCT may have fault geometries or properties that inhibit continued rupture. Our results indicate a displacement-driven fault maturation process. The multi-plane Australia plate tearing likely creates a western SCT with diffuse strain accommodated along a network of disorganized faults. After ∼90 km of cumulative displacement (∼900,000 yr of plate motion), strain localizes and faults align, allowing the SCT to host large earthquakes. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110039
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Geosciences, The Pennsylvania State University, 503 Deike Building, University ParkPA 16802, United States
Recommended Citation:
Neely J.S.,Furlong K.P.. Evidence of displacement-driven maturation along the San Cristobal Trough transform plate boundary[J]. Earth and Planetary Science Letters,2018-01-01,485