DOI: 10.1016/j.epsl.2018.07.014
Scopus记录号: 2-s2.0-85049927343
论文题名: Seismicity and structure of Nazca Plate subduction zone in southern Peru
作者: Lim H. ; Kim Y. ; Clayton R.W. ; Thurber C.H.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 498 起始页码: 334
结束页码: 347
语种: 英语
英文关键词: double-difference tomography
; Nazca Plate
; relocation
; seismicity
; southern Peru
; subduction zone system
Scopus关键词: Earthquakes
; Plates (structural components)
; Relocation
; Shear flow
; Shear waves
; Tomography
; Velocity
; Wave propagation
; Double-difference tomography
; Nazca plate
; seismicity
; southern Peru
; Subduction zones
; Tectonics
; earthquake hypocenter
; Nazca plate
; P-wave
; relocation
; S-wave
; seismicity
; subduction zone
; tomography
; wave velocity
; Ica
; Nazca
; Peru
英文摘要: We define subducting plate geometries in the Nazca subduction zone by (re)locating intra-slab earthquakes in southern Peru (14–18°S) and using previously published converted phase analysis results to clarify the slab geometry and inferred relationships to the seismicity. We also provide both P- and S-wave velocity models of the subducting Nazca Plate and mantle layer above the slab using double-difference tomography to understand upper-plate volcanism and subduction zone process. The double-difference constraints for determining the hypocenters and velocity model ensure high accuracy of the relative location of earthquakes with respect to velocity structure. The relocated seismicity shows a smooth contortion in the slab-dip transition zone for ∼400 km between the shallow (30°)-to-flat dipping interface to the northwest and the 30°-dipping interface to the southeast. We find a significant slab-dip difference (up to 10°) between our results and previous slab models along the profile region sampling the horizontal slab at a depth of ∼85–95 km. Robust features in both P- and S-wave tomography inversions are both arc-normal and along-arc velocity variations. In the arc-normal direction, all profile results show that the slab velocities beneath the forearc (down to a depth of ∼100 km) transition to higher velocities beneath the backarc (at ∼100–140 km depth). In the along-arc direction, velocities of the subducting flat slab are shown to be depressed compared to those of the normal-dip slab. In addition, high shear-wave velocities and low Vp/Vs are detected in the mantle layer above the flat slab, indicating its cold and dry environment. Such differences in the velocity structures for the slab and mantle wedge between the two regions may indicate different hydration states, which greatly affects the upper-plate structure of southern Peru. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109747
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
There are no files associated with this item.
作者单位: School of Earth and Environmental Sciences, Seoul National University, Seoul, 08826, South Korea; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Department of Geoscience, University of Wisconsin-Madison, Madison, WI 53706-1692, United States
Recommended Citation:
Lim H.,Kim Y.,Clayton R.W.,et al. Seismicity and structure of Nazca Plate subduction zone in southern Peru[J]. Earth and Planetary Science Letters,2018-01-01,498