Results 71 to 80 of about 45,633 (206)

Complex anisotropy beneath the Peruvian flat slab from frequency-dependent, multiple-phase shear wave splitting analysis [PDF]

, 2013
Flat or shallow subduction is a relatively widespread global occurrence, but the dynamics remain poorly understood. In particular, the interaction between flat slabs and the surrounding mantle flow has yet to be studied in detail.
Eakin, Caroline M., Long, Maureen D.
core   +1 more source

Light oxygen isotopic composition in deep mantle reveals oceanic crust subduction before 3.3 billion years ago

Communications Earth & Environment
Compositional heterogeneity exists in Earth’s deep mantle, which can be caused by the subduction of oceanic slabs. How early this process started on Earth remains highly debated due to the scarcity of early Archean materials with pristine mantle ...
Dongjian Ouyang, Huiming Bao, Gary R. Byerly, Qiuli Li   +3 more
doaj   +1 more source

Small-Scale Heterogeneities of the Upper Mantle

, 1997
Models derived from controlled source seismology (reflection and refraction data) and long-period seismology provide the impression that the upper mantle is rather homogeneous. For near-vertical reflections the mantle appears transparent if compared to the reflective lower crust.
Wenzel, Friedemann, Fuchs, Karl, Tittgemeyer, Marc, Ryberg, Trond   +3 more
openaire   +3 more sources

Unraveling the Connection Between Subsurface Stress and Geomorphic Features

Geophysical Research Letters
The tectonic stress field induces surface deformation. At long wavelengths, both lithospheric heterogeneity (changes in the thickness and density of crust and lithospheric mantle) and basal tractions from mantle convection contribute to the stress field.
B. Kuhasubpasin, S. Moon, C. Lithgow‐Bertelloni   +2 more
doaj   +1 more source

Thermal convection in a heterogeneous mantle

Comptes Rendus. Géoscience, 2003
Both seismology and geochemistry show that the Earth's mantle is chemically heterogeneous on a wide range of scales. Moreover, its rheology depends strongly on temperature, pressure and chemistry. To interpret the geological data, we need a physical understanding of the forms that convection might take in such a mantle.
Davaille, Anne, Le Bars, Michael, Carbonne, Catherine   +2 more
openaire   +1 more source

Implication of the lopsided growth for the viscosity of Earth's inner core [PDF]

, 2012
Two main seismic features characterize the Earth's inner core: a North-South polar anisotropy and an East-West asymmetry of P-wave velocity and attenuation. Anisotropy is expected if shear deformation is induced by convective motions.
Alboussiere, Alfe, Amit, Anderson, Aubert, Bergman, Buffett, Buffett, Calvet, Christensen, de Koker, Deguen, Deguen, Deguen, Deguen, Deuss, Dziewonski, Finlay, Gubbins, Hugau Mizzon, Jaupart, Jeanloz, Labrosse, Marc Monnereau, McKenzie, Monnereau, Monnereau, Monnereau, Poirier, Poupinet, Pozzo, Schubert, Stacey, Tanaka, Vočadlo, Weber, Yoshida   +36 more
core   +3 more sources

How P‐Wave Scattering Throughout the Entire Mantle Mimics the High‐Frequency Pdiff and Its Coda

Geophysical Research Letters
We document the arrival of seismic energy in the core shadow zone up to large distances beyond 150° more than 100 s prior to the core phases. Numerical simulations of the energy transport in an established heterogeneity model show that scattering ...
Tuo Zhang, Christoph Sens‐Schönfelder, Marcelo Bianchi, Klaus Bataille   +3 more
doaj   +1 more source

CHAOTIC UPPER MANTLE HETEROGENEITY

, 2010
[1] The intrinsic structure of the isotope data set of samples from the Mid-Atlantic Ridge and East Pacific Rise, believed to represent the isotopic composition of their mantle source, reveals a close relationship between sample spatial distribution and their geochemical features. The spatial distribution of their isotopic heterogeneity is self-similar
Pietro Armienti, D. Gasperini
openaire   +1 more source

Mantle heterogeneity caused by trapped water in the Southwest Basin of the South China Sea. [PDF]

Nat Commun, 2023
Tian J, Ma Z, Lin J, Xu M, Yu X, Le BM, Zhang X, Zhang F, Guo L.   +8 more
europepmc   +1 more source

Global mantle isotopic anomalies linked to supercontinent-superocean evolution for the past 700 million years

Communications Earth & Environment
Earth’s mantle isotopic composition is highly heterogeneous, with enriched and depleted regions1–3 shaped by a complex history of depletion and re-enrichment over 4.5 billion years.
Piero A. B. de Sampaio, Zheng-Xiang Li, Luc S. Doucet   +2 more
doaj   +1 more source