منابع مشابه
Bending stress and dissipation in subducted lithosphere
[1] Oceanic lithosphere undergoes permanent deformation during subduction once the stresses exceed the elastic limit. Departures from elastic behavior occur by brittle failure in the shallow lithosphere and by a combination of lowand high-temperature creep at greater depths. We combine laboratory-based rheological models with estimates of slab shape from earthquake hypocenters to quantify the b...
متن کاملMantle shear-wave tomography and the fate of subducted slabs.
A new seismic model of the three-dimensional variation in shear velocity throughout the Earth's mantle is presented. The model is derived entirely from shear bodywave travel times. Multibounce shear waves, core-reflected waves and SKS and SKKS waves that travel through the core are used in the analysis. A unique aspect of the dataset used in this study is the use of bodywaves that turn at shall...
متن کاملDispersion of P waves in subducted lithosphere Evidence for an eclogite layer
Cold, subducted lithosphere has relatively fast seismic velocity which leads to early arrivals for some vent-station paths. The effect is very large for events in the Tonga-Kermadec ep seismic zone recorded at certain New Zealand stations. These particular arrivals are very high-frequency (3 Hz or greater) and sometimes r emble two distinct phases, the later arrival appearing at about the time ...
متن کاملThe fate of subducted continental margins: Two-stage exhumation of the high-pressure to ultrahigh-pressure Western Gneiss Region, Norway
Thermobarometry suggests that ultrahigh-pressure (UHP) to high-pressure (HP) rocks across the Western Gneiss Region ponded at the Moho following as much as 100 km of exhumation through the mantle and before exhumation to the upper crust. Eclogite across the c. 22 000 km study area records minimum pressures of c. 8–18 kbar and temperatures of c. 650–780 C. One orthopyroxene eclogite yields an UH...
متن کاملPossible density segregation of subducted oceanic lithosphere along a weak serpentinite layer and implications for compositional stratification of the Earth's mantle
There is growing evidence that the top part of the oceanic mantle is pervasively serpentinized prior to subduction. Because the interior of a subducting slab heats up slowly, the serpentinized layer can be preserved for tens of Myr, thereby forming a weak zone that allows for mechanical decoupling between the oceanic crust and underlying lithospheric mantle. Once the crust is eclogitized, a she...
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ژورنال
عنوان ژورنال: Nature
سال: 1988
ISSN: 0028-0836,1476-4687
DOI: 10.1038/331113a0