We located the aftershocks of the 4 February 1975 Haicheng, China, aftershock sequence using an arrival time difference (ATD) simultaneous inversion method for determining the near-source (in situ) velocity and the location of the aftershocks with respect to a master event. The aftershocks define a diffuse zone, 70 km x 25 kin, trending west-northwest, perpendicular to the major structural tren...

s of 33rd International Geological Congress, 6–14 August 2008, Oslo. Coltorti, M., Bonadiman, C., O’Reilly, S. Y., Griffin, W. L. & Pearson, N. J. 2010. Buoyant ancient continental mantle embedded in oceanic lithospheric (Sal Island, Cape Verde Archipelago). Lithos, doi: 10.1016/j.lithos.2009.11.005. Davies, G. R., Nixon, P. H., Pearson, D. G. & Obata, M. 1993. Tectonic implications of graphiti...

This study investigates petrology and major, minor, and rare earth elements ‎geochemistry of ‎East Iranian Eocene–Oligocene volcanic rocks in Sistan suture ‎zone, to examine their ‎petrogenesis and magma evolution. The volcanic rocks include andesite, trachy-andesite, dacite ‎and rhyolite. ‎These calc-alkaline rocks of high-K series are enriched in Large ‎Ion Lithophile ‎Elements of Rb and Ba a...

The lithosphere, which includes the crust and the uppermost part of the mantle, is the mechanically strong outer shell of the Earth. The lithosphere is broken into a dozen or so pieces, called the tectonic plates. Constant motions between these tectonic plates cause lithospheric deformation, which leads to mountain building, earthquakes, and many other geological processes, including geohazards...

We compare observed Pioneer Venus orbiter (PVO) gravity profiles over Aphrodite Terra to profiles predicted from models of thermal isostasy, mantle convection, and Airy compensation. Similar approaches are used in order to investigate how well the models can be distinguished with the PVO data. Topography profiles across Aphrodite are compared to model spreading ridge profiles in order to furthe...

W e consider a series of simple calculations with a step-function change in thickness of the lithosphere and imposed, far-field boundary conditions to illustrate the influence of the lithosphere on mantle flow. We consider the effect of aspect ratio and far-field boundary conditions on the small-scale flow driven by a discontinuity in the thickness of the lithosphere. In an isothermal mantle, w...

Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their...

[1] The scaling of plate tectonic convection is investigated by simulating thermal convection with pseudoplastic rheology and strongly temperature‐dependent viscosity. The effect of mantle melting is also explored with additional depth‐dependent viscosity. Heat flow scaling can be constructed with only two parameters, the internal Rayleigh number and the lithospheric viscosity contrast, the lat...

High attenuation of short-period body waves and extremely low surface-wave group velocities have been found for seismic paths that traverse the crust and upper mantle beneath the concave side of the Lesser Antilles island arc (eastern Caribbean). The observations can be explained in terms of the currently accepted models of lithospheric plate subduction at other island arcs such as Fiji-Tonga, ...

[1] The Gravity Recovery and Climate Experiment (GRACE) satellite mission was launched in March 2002 and has an expected 5-year lifetime. One potential application of GRACE measurements of time-variable gravity will be to isolate the postglacial rebound signal, which can then be used to estimate the Earth’s viscosity structure. In this paper we present a sensitivity analysis of simulated GRACE ...