Lithospheric structure beneath the northern Central Andean Plateau from the joint inversion of ambient noise and earthquake-generated surface waves
dc.contributor.author | Ward, Kevin M. | |
dc.contributor.author | Zandt, George | |
dc.contributor.author | Beck, Susan | |
dc.contributor.author | Wagner, Lara S. | |
dc.contributor.author | Tavera, Hernando | |
dc.date.accessioned | 2017-03-02T00:58:55Z | |
dc.date.available | 2017-03-02T00:58:55Z | |
dc.date.issued | 2016-11 | |
dc.identifier.citation | Lithospheric structure beneath the northern Central Andean Plateau from the joint inversion of ambient noise and earthquake-generated surface waves 2016, 121 (11):8217 Journal of Geophysical Research: Solid Earth | en |
dc.identifier.issn | 21699313 | |
dc.identifier.doi | 10.1002/2016JB013237 | |
dc.identifier.uri | http://hdl.handle.net/10150/622701 | |
dc.description.abstract | The Central Andean Plateau (CAP), as defined by elevations in excess of 3 km, extends over 1800 km along the active South American Cordilleran margin making it the second largest active orogenic plateau on Earth. The uplift history of this high Plateau, with an average elevation around 4 km above sea level, remains uncertain as paleoelevation studies along the CAP suggest a complex, nonuniform uplift history. As part of the Central Andean Uplift and the Geodynamics of High Topography (CAUGHT) project, we image the S wave velocity structure of the crust and upper mantle using surface waves measured from ambient noise and teleseismic earthquakes to investigate the upper mantle component of plateau uplift. We observe three main features in our S wave velocity model including (1) a positive velocity perturbation associated with the subducting Nazca slab; (2) a negative velocity perturbation below the sub-Andean crust that we interpret as anisotropic Brazilian cratonic lithosphere; and (3) a high-velocity feature in the mantle above the slab that extends along the length of the Altiplano from the base of the Moho to a depth of similar to 120 km. A strong spatial correlation exists between the lateral extent of this high-velocity feature and the relatively lower elevations of the Altiplano basin suggesting a potential relationship. Determining if this high-velocity feature represents a small lithospheric root or foundering of orogenic lithosphere requires more integration of observations, but either interpretation implies a strong geodynamic connection with the uppermost mantle and the current topography of the northern CAP. | |
dc.description.sponsorship | NSF [EAR-1415914, EAR-0943991, EAR-0907880]; National Science Foundation | en |
dc.language.iso | en | en |
dc.publisher | AMER GEOPHYSICAL UNION | en |
dc.relation.url | http://doi.wiley.com/10.1002/2016JB013237 | en |
dc.rights | ©2016. American Geophysical Union. All Rights Reserved. | en |
dc.title | Lithospheric structure beneath the northern Central Andean Plateau from the joint inversion of ambient noise and earthquake-generated surface waves | en |
dc.type | Article | en |
dc.contributor.department | Univ Arizona, Dept Geosci | en |
dc.identifier.journal | Journal of Geophysical Research: Solid Earth | en |
dc.description.note | 6 month embargo; Version of record online: 25 November 2016 | en |
dc.description.collectioninformation | This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu. | en |
dc.eprint.version | Final published version | en |
dc.contributor.institution | Department of Geology and Geophysics; University of Utah; Salt Lake City Utah USA | |
dc.contributor.institution | Department of Geosciences; University of Arizona; Tucson Arizona USA | |
dc.contributor.institution | Department of Geosciences; University of Arizona; Tucson Arizona USA | |
dc.contributor.institution | Department of Terrestrial Magnetism; Carnegie Institution of Washington; Washington District of Columbia USA | |
dc.contributor.institution | Instituto Geofísico del Perú; Lima Peru | |
refterms.dateFOA | 2017-05-26T00:00:00Z | |
html.description.abstract | The Central Andean Plateau (CAP), as defined by elevations in excess of 3 km, extends over 1800 km along the active South American Cordilleran margin making it the second largest active orogenic plateau on Earth. The uplift history of this high Plateau, with an average elevation around 4 km above sea level, remains uncertain as paleoelevation studies along the CAP suggest a complex, nonuniform uplift history. As part of the Central Andean Uplift and the Geodynamics of High Topography (CAUGHT) project, we image the S wave velocity structure of the crust and upper mantle using surface waves measured from ambient noise and teleseismic earthquakes to investigate the upper mantle component of plateau uplift. We observe three main features in our S wave velocity model including (1) a positive velocity perturbation associated with the subducting Nazca slab; (2) a negative velocity perturbation below the sub-Andean crust that we interpret as anisotropic Brazilian cratonic lithosphere; and (3) a high-velocity feature in the mantle above the slab that extends along the length of the Altiplano from the base of the Moho to a depth of similar to 120 km. A strong spatial correlation exists between the lateral extent of this high-velocity feature and the relatively lower elevations of the Altiplano basin suggesting a potential relationship. Determining if this high-velocity feature represents a small lithospheric root or foundering of orogenic lithosphere requires more integration of observations, but either interpretation implies a strong geodynamic connection with the uppermost mantle and the current topography of the northern CAP. |