气候变化领域集成服务门户(CCPortal): Spatial Variations in Crustal and Mantle Anisotropy Across the North American-Caribbean Boundary on Haiti

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DOI	10.1029/2019JB018438
	Spatial Variations in Crustal and Mantle Anisotropy Across the North American-Caribbean Boundary on Haiti
	Possee D.; Keir D.; Harmon N.; Rychert C.; Eakin C.; Rolandone F.; Leroy S.; Corbeau J.; Stuart G.; Boisson D.; Momplaisir R.; Prépetit C.
发表日期	2020
ISSN	21699313
卷号	125 期号:6
英文摘要	Haiti, on the island of Hispaniola, is situated across the North American-Caribbean plate boundary at the transition point between oblique subduction in the east and a transform plate boundary in the west. Here we use shear wave splitting measurements from S waves of local (0–50 km) and intermediate depth (50–150 km) earthquakes as well as SK(K)S phases from teleseismic earthquakes to ascertain good spatial and vertical resolution of the azimuthal anisotropic structure. This allows us to place new constraints on the pattern of deformation in the crust and mantle beneath this transitional region. SK(K)S results are dominated by plate boundary parallel (E-W) fast directions with ~1.9 s delay times, indicating subslab trench parallel mantle flow is continuing westward along the plate boundary. Intermediate depth earthquakes originating within the subducting North American plate show a mean fast polarization direction of 065° and delay time of 0.46 s, subparallel to the relative plate motion between the Caribbean and North American plates (070°). We suggest a basal shear zone within the lower ductile crust and upper lithospheric mantle as being a potential major source of anisotropy above the subducting slab. Upper crustal anisotropy is isolated using shear wave splitting measurements on local seismicity, which show consistent delay times on the order of 0.2 s. The fast polarization directions indicate that the crustal anisotropy is controlled by the fault networks in close proximity to the major strike-slip faults, which bisect the north and south of Haiti, and by the regional stress field where faulting is less pervasive. © 2020. The Authors.
英文关键词	anisotropy; Caribbean; Haiti; plate boundary; shear wave splitting
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187810
作者单位	School of Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, United Kingdom; Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Florence, Italy; Research School of Earth Sciences, The Australian National University, Acton, ACT, Australia; Sorbonne Université, CNRS-INSU, Institut des Sciences de la Terre Paris (ISTeP), Paris, France; Université de Paris, Institut de Physique du Globe de Paris, CNRS, Saint-Pierre, France; Observatoire Volcanologique et Sismologique de Martinique, IPGP, CNRS, Saint-Pierre, France; School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Faculté des Sciences, Université d'Etat d'Haïti, Port-au-Prince, Haiti; L'Unité Technique de Sismologie (UTS)/BME, Port-au-Prince, Haiti
推荐引用方式 GB/T 7714	Possee D.,Keir D.,Harmon N.,et al. Spatial Variations in Crustal and Mantle Anisotropy Across the North American-Caribbean Boundary on Haiti[J],2020,125(6).
APA	Possee D..,Keir D..,Harmon N..,Rychert C..,Eakin C..,...&Prépetit C..(2020).Spatial Variations in Crustal and Mantle Anisotropy Across the North American-Caribbean Boundary on Haiti.Journal of Geophysical Research: Solid Earth,125(6).
MLA	Possee D.,et al."Spatial Variations in Crustal and Mantle Anisotropy Across the North American-Caribbean Boundary on Haiti".Journal of Geophysical Research: Solid Earth 125.6(2020).