Impact of the lithosphere on dynamic topography: Insights from analogue modeling

Density anomalies beneath the lithosphere are expected to generate dynamic topography at the Earth's surface due to the induced mantle flow stresses which scale linearly with density anomalies, while the viscosity of the upper mantle is expected to control uplift rates. However, limited attenti...

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Bibliographic Details
Authors: Sembroni, Andrea, Kiraly, Agnes, Faccenna, Claudio, Funiciello, Francesca, Becker, Thorsten W., Goblig, Jan, Fernández Ortiga, Manel
Format: article
Status:Published version
Publication Date:2017
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/148244
Online Access:http://hdl.handle.net/10261/148244
Access Level:Open access
Keyword:Analogue modelling
Dynamic topography
Lithosphere
Mantle anomaly
Surface bulge
Uplift
Description
Summary:Density anomalies beneath the lithosphere are expected to generate dynamic topography at the Earth's surface due to the induced mantle flow stresses which scale linearly with density anomalies, while the viscosity of the upper mantle is expected to control uplift rates. However, limited attention has been given to the role of the lithosphere. Here we present results from analogue modeling of the interactions between a density anomaly rising in the mantle and the lithosphere in a Newtonian system. We find that, for instabilities with wavelengths of the same order of magnitude as lithosphere thickness, the uplift rate and the geometry of the surface bulge are inversely correlated to the lithosphere thickness. We also show that a layered lithosphere may modulate the topographic signal. With respect to previous approaches our models represent a novel attempt to unravel the way normal stresses generated by mantle flow are transmitted through a rheologically stratified lithosphere and the resulting topographic signal. © 2017. American Geophysical Union. All Rights Reserved.