Results 21 to 30 of about 19,207 (163)

Noble gases confirm plume-related mantle degassing beneath Southern Africa

Nature Communications, 2019
Southern Africa is characterised by unusually elevated topography and abnormal heat flow. This can be explained by thermal perturbation of the mantle, but the origin of this is unclear.
S. M. V. Gilfillan, D. Györe, S. Flude, G. Johnson, C. E. Bond, N. Hicks, R. Lister, D. G. Jones, Y. Kremer, R. S. Haszeldine, F. M. Stuart   +10 more
doaj   +1 more source

Modeling of Seismic Anisotropy Observations Reveals Plausible Lowermost Mantle Flow Directions Beneath Siberia

Geochemistry, Geophysics, Geosystems, 2021
Observations of seismic anisotropy just above the core‐mantle boundary are a powerful way to understand the dynamics of the lowermost mantle. Here we present models of seismic anisotropy in the lowermost mantle beneath Siberia based on new and previously
Neala Creasy, Angelo Pisconti, Maureen D. Long, Christine Thomas   +3 more
doaj   +1 more source

Depth-varying azimuthal anisotropy and mantle flow in the Patagonian slab window

Seismica
Subduction of spreading ridges forms slab windows which perturb the local structure and dynamics of the upper mantle. Slab windows may alter the pattern of mantle flow and serve as portals for the exchange of mantle material between upper mantle ...
Hannah Mark, Douglas Wiens, Walid Ben Mansour, Zhengyang Zhou   +3 more
doaj   +1 more source

Quaternary Volcanism in Myanmar: A Record of Indian Slab Tearing in a Transition Zone From Oceanic to Continental Subduction

Geochemistry, Geophysics, Geosystems, 2020
Magmatic processes that occur during the transition from oceanic to continental subduction and collision in orogens are critical and still poorly resolved.
L. Y. Zhang, W. M. Fan, L. Ding, M. N. Ducea, A. Pullen, J. X. Li, Y. L. Sun, Y. H. Yue, F. L. Cai, C. Wang, T. P. Peng, Kyaing Sein   +11 more
doaj   +1 more source

Subduction to the lower mantle – a comparison between geodynamic and tomographic models [PDF]

Solid Earth, 2012
It is generally believed that subduction of lithospheric slabs is a major contribution to thermal heterogeneity in Earth's entire mantle and provides a main driving force for mantle flow.
T. W. Becker, T. H. Torsvik, B. Steinberger   +2 more
doaj   +1 more source

Characterizing the Complexity of Subduction Zone Flow With an Ensemble of Multiscale Global Convection Models

Geochemistry, Geophysics, Geosystems
Subduction zones are fundamental features of Earth's mantle convection and plate tectonics, but mantle flow and pressure around slabs are poorly understood because of the lack of direct observational constraints on subsurface flow.
Samuel L. Goldberg, Adam F. Holt
doaj   +1 more source

Anomalously thin transition zone and apparently isotropic upper mantle beneath Bermuda: Evidence for upwelling

Geochemistry, Geophysics, Geosystems, 2013
The origin of the Bermuda swell and volcanism remains enigmatic. The lack of an associated time‐progressive hotspot track and absence of present‐day volcanic activity make it difficult to reconcile with a deep mantle plume model.
Margaret H. Benoit, Maureen D. Long, Scott D. King   +2 more
doaj   +1 more source

Spatiotemporal Variations in Surface Heat Loss Imply a Heterogeneous Mantle Cooling History

Geophysical Research Letters, 2021
Earth's heat budget is strongly influenced by spatial and temporal variations in surface heat flow caused by plate tectonic cycles. Here, we use a novel set of paleo‐seafloor age grids extending back to the mid‐Paleozoic to infer spatiotemporal ...
Krister S. Karlsen, Clinton P. Conrad, Mathew Domeier, Reidar G. Trønnes   +3 more
doaj   +1 more source

Resolving Seismic Anisotropy of the Lithosphere–Asthenosphere in the Central/Eastern Alps Beneath the SWATH-D Network

Frontiers in Earth Science, 2021
The Alpine orogeny is characterized by tectonic sequences of subduction and collision accompanied by break-off events and possibly preceded by a flip of subduction polarity. The tectonic evolution of the transition to the Eastern Alps has thus been under
Frederik Link, Georg Rümpker
doaj   +1 more source

Seismic Anisotropy and Mantle Flow in the Sumatra Subduction Zone Constrained by Shear Wave Splitting and Receiver Function Analyses

Geochemistry, Geophysics, Geosystems, 2020
To systematically investigate seismic azimuthal anisotropy in the Sumatra subduction zone and probe mantle dynamics associated with the subduction of the Australian Plate beneath the Sunda Plate, a total of 169 pairs of teleseismic XKS (including PKS ...
Fansheng Kong, Stephen S. Gao, Kelly H. Liu, Jie Zhang, Jiabiao Li   +4 more
doaj   +1 more source