Mantle wedge hydration in Nicaragua from Local Earthquake Tomography.

Dinc-Akdogan, Nilay, Rabbel, Wolfgang, Flueh, Ernst R. and Taylor, W. (2011) Mantle wedge hydration in Nicaragua from Local Earthquake Tomography. Open Access Geophysical Journal International, 186 (1). pp. 92-112. DOI 10.1111/j.1365-246X.2011.05041.x.

[img]
Preview
Text
Dinc.pdf - Published Version

Download (1536Kb)

Supplementary data:

Abstract

The continental margin of Nicaragua and Costa Rica is characterized by significant lateral changes from north to south such as a decreasing dip of the slab, a decreasing magma production and a shift in the volcanic front. To investigate this transition, a joint on- and offshore local earthquake tomography was performed. Low P-wave velocities and high Vp/Vs ratios, indicative for hydration, were found in the upper-mantle and lowermost crust beneath the Sandino Basin. The mantle wedge hydration can be estimated to 2.5 wt. per cent beneath south Nicaragua. In contrast, the mantle wedge beneath north Costa Rica is weakly or not hydrated. The hydration leads to a local gap in the seismicity in Nicaragua. The lateral transition between the hydrated and non-hydrated areas occurs within a distance of about 10 km. This transition coincides with a change in the crustal thickness in the order of 5–10 km, thickening to the south, and in the tectonic regimes. The change in the tectonic regimes towards a stronger extension along the margin of Nicaragua could be the key for understanding the observations: the extension may support the opening of pathways for a wide zone of fluid migration and hydration through the overriding plate which are identified with areas of low Vp, high Vp/Vs and low seismicity.

Document Type: Article
Additional Information: This article has been published in Geophysical Journal International ©2011 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Keywords: Seismology; Geophysics; Hydrothermal systems; Seismic tomography; Subduction zone processes; Continental margins: convergent
Research affiliation: OceanRep > SFB 574
OceanRep > SFB 574 > A2
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
Kiel University
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1111/j.1365-246X.2011.05041.x
ISSN: 0956-540X
Projects: Future Ocean
Contribution Number:
ProjectNumber
SFB 574154
Expeditions/Models/Experiments:
Date Deposited: 13 Jul 2010 11:00
Last Modified: 10 Jul 2018 10:02
URI: http://oceanrep.geomar.de/id/eprint/8628

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...