scholarly journals Role of mantle flow in Nubia-Somalia plate divergence

2015 ◽  
Vol 42 (2) ◽  
pp. 290-296 ◽  
Author(s):  
D. S. Stamps ◽  
G. Iaffaldano ◽  
E. Calais
Keyword(s):  
Mantle Flow

THE ROLE OF DEEP MANTLE FLOW IN SHAPING THE HAWAIIAN-EMPEROR BEND

2017 ◽  
Author(s):  
Simon Williams ◽  
◽  
Rakib Hassan ◽  
Dietmar Müller ◽  
Michael Gurnis ◽  
...  
Keyword(s):  
Mantle Flow ◽  
Deep Mantle

scholarly journals Role of lateral mantle flow in the evolution of subduction systems: insights from laboratory experiments

2004 ◽  
Vol 157 (3) ◽  
pp. 1393-1406 ◽  
Author(s):  
Francesca Funiciello ◽  
Claudio Faccenna ◽  
Domenico Giardini
Keyword(s):  
Laboratory Experiments ◽  
Mantle Flow

The role of shear heating in lubricating mantle flow

1997 ◽  
Vol 151 (1-2) ◽  
pp. 33-42 ◽  
Author(s):  
Arie P. van den Berg ◽  
David A. Yuen
Keyword(s):  
Mantle Flow ◽  
Shear Heating

scholarly journals Effects of basal drag on subduction dynamics from 2D numerical models

2020 ◽  
Author(s):  
Lior Suchoy ◽  
Saskia Goes ◽  
Benjamin Maunder ◽  
Fanny Garel ◽  
Rhodri Davies
Keyword(s):  
Numerical Models ◽  
Force Balance ◽  
Plate Motion ◽  
Mantle Flow ◽  
Plate Motions ◽  
Flow Models ◽  
Plate Size ◽  
Modelling Studies ◽  
Subduction System

Abstract. Subducting slabs are an important driver of plate motions, yet the force balance governing subduction dynamics remains incompletely understood. Basal drag has been proposed to be a minor contributor to subduction forcing, because of the lack of correlation between plate size and velocity in observed and reconstructed plate motions. Furthermore, in single subduction system models, low basal drag, associated with a low ratio of asthenospheric to lithospheric viscosity, leads to subduction behaviour most consistent with the observation that trench migration velocities are generally low compared to convergence velocities. By contrast, analytical calculations and global mantle flow models indicate basal drag can be substantial. In this study, we revisit this problem by examining the drag at the base of the lithosphere, for a single subduction system, in 2D models with a free trench and composite non-linear rheology. We compare the behaviour of short and long plates for a range of asthenospheric and lithospheric rheologies. We reproduce results from previous modelling studies, including low ratios of trench over plate motions. However, we also find that any combination of asthenosphere and lithosphere viscosity that produces Earth-like subduction behaviour leads to a correlation of velocities with plate size, due to the role of basal drag. By examining Cenozoic plate motion reconstructions, we find that slab age and plate size are positively correlated: higher slab pull for older plates tends to be offset by higher basal drag below these larger plates. This, in part, explains the lack of plate velocity-size correlation in observations, despite the important role of basal drag in the subduction force-balance.

scholarly journals SKS splitting observations across the Iranian plateau and Zagros: the role of lithosphere deformation and mantle flow

2020 ◽  
Author(s):  
Ayoub Kaviani ◽  
Meysam Mahmoodabadi ◽  
Georg Rümpker ◽  
Farzam Yamini-Fard ◽  
Mohammad Tatar ◽  
...  
Keyword(s):  
Seismic Anisotropy ◽  
Mantle Flow ◽  
Combined System ◽  
Iranian Plateau ◽  
Sks Splitting ◽  
Lithosphere Thickness ◽  
Lithosphere Deformation ◽  
Tectonic Boundaries ◽  
Fast Polarization

<p>We used more than one decade of core-refracted teleseismic shear (SKS) waveforms recorded at more than 160 broadband seismic stations across the Iranian plateau and Zagros to investigate seismic anisotropy beneath the region. Splitting analysis of SKS waveforms provides two main parameters, i.e., fast polarization direction and split delay time, which serve as proxies for the trend and strength of seismic anisotropy beneath the stations. Our observation revealed a complex pattern of splitting parameters with variations in the trend and strength of anisotropy across the tectonic boundaries. We also verified the presence of multiple layers of anisotropy in conjunction with the lithosphere deformation and mantle flow field. Our observation and modeling imply that a combined system of lithosphere deformation and asthenospheric flow is likely responsible for the observed pattern of anisotropy across the Iranian Plateau and Zagros. The rotational pattern of the fast polarization directions observed locally in Central Zagros may indicate the diversion of mantle flow around a continental keel beneath the Zagros. The correlation between the variation in lithosphere thickness and the trend of anisotropy in the study area implies that the topography of the base of lithosphere is also a determining factor for the pattern of mantle flow inferred from the observations.</p>

scholarly journals Shear Wave Splitting and Mantle Flow in Mexico: What Have we Learned?

2017 ◽  
Vol 56 (2) ◽  
Author(s):  
Raúl W. Valenzuela ◽  
Gerardo León Soto
Keyword(s):  
Shear Wave ◽  
Slow Wave ◽  
Upper Mantle ◽  
Subduction Zones ◽  
Seismic Anisotropy ◽  
Shear Wave Splitting ◽  
Special Focus ◽  
Mantle Flow ◽  
Wave Splitting

A review is presented of the shear wave splitting studies of the upper mantle carried out in Mexico during the last decade. When a seismic wave enters an anisotropic medium it splits, which means that a fast and a slow wave are produced. Two parameters are used to quantify anisotropy. These are the fast polarization direction and the delay time between the fast and the slow wave. An example of the measurement technique is presented using an SKS phase because most observations are based on teleseismic data. Results of two studies using local S waves from intraslab earthquakes are also discussed. Key aspects of the interpretation of splitting measurements are explained. These include the depth localization of anisotropy, the relation-ship between olivine fabrics and mantle flow, the role of absolute plate motion, and the role of relative plate motions with a special focus on subduction zones. An important motivation for studying seismic anisotropy is that it makes it possible to constrain the characteristics of upper mantle flow and its relationship to tectonic processes. Mexico has many diverse tectonic environments, some of which are currently active, or were formerly active, and have left their imprint on seismic anisotropy. This has resulted in a wide variety of mechanisms for driving mantle flow. Broadly speaking, the discussion is organized into the following regions: Baja California peninsula, Western Mexican Basin and Range, northern and northeastern Mexico, the Middle America Trench, the Yucatán peninsula, and lowermost mantle anisotropy. Depending on the unique characteristics encountered within each region, the relationship between anisotropy and mantle flow is explored.

scholarly journals Role of mantle flow at the North Fiji Basin: Insights from anomalous topography

2006 ◽  
Vol 7 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
Nan Zhang ◽  
Russell N. Pysklywec
Keyword(s):  
Mantle Flow ◽  
The North ◽  
North Fiji Basin
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