Geological studies of mantle xenoliths entrained in late Neogene–Quaternary lavas from the southern Sierra Nevada region and regional geophysical studies suggest that the highdensity mantle lithosphere that formed beneath the Sierra Nevada batholith in conjunction with arc magmatism is being convectively removed as a ‘‘drip’’ structure. This structure, as imaged seismically, is roughly cylindri...

a r t i c l e i n f o a b s t r a c t Isostatic and dynamic models of Earth's surface topography can provide important insights into the driving processes of tectonic deformation. We analyze these two estimates for the tectonically-active western United States using refined structural models derived from EarthScope USArray. For the crust, use of recent Moho depth measurements and crustal densit...

Contained fluids heated from below spontaneously organize into convection cells when sufficiently far from conductive equilibrium. Fluids can also be organized by surface tension and other forces at the top. Plate tectonics was once regarded as passive motion of plates on top of mantle convection cells but it now appears that continents and plate tectonics organize the flow in the mantle. The f...

We revisit a recent study by Forte & Mitrovica in which global geophysical observables associated with mantle convection were inverted and the existence of a strong increase in viscosity near a depth of 2000 km was inferred. Employing mineral-physics data and theory we also showed that, although there are chemical anomalies in the lowermost mantle, they are unable to inhibit the dominant therma...

background: poorly educated people in some parts of iran use burned mantles as a wound healing medicine. materials and methods: to perform surface area measurement, twenty rats were divided randomly into two groups of 10 animals each. the first group received topical burned radioactive lantern mantle powder on the first to third days after making excision wounds. the second group received non-r...

[1] We provide new insights into the lithosphere-mantle coupling problem through a joint modeling of lithosphere dynamics and mantle convection and through comparison of model results with the high resolution velocity gradient tensor model along the Earth’s plate boundary zones. Using a laterally variable effective viscosity lithosphere model, we compute depth integrated deviatoric stresses ass...

The surface of Mars consists of an old, heavily cratered and elevated southern hemisphere and younger, resurfaced and depressed northern hemisphere, a feature often termed the crustal dichotomy. The global crustal structure [Zuber et al., 2000] revealed by topography and gravity data from the Mars Global Surveyor spacecraft, and the possible late formation of the boundary zone between the hemis...

The effects of compositional discontinuities of density and viscosity in the Earth's mantle on the ascent of mantle plume heads is studied using a boundary integral numerical technique. Three specific problems are considered: (1) a plume head rising away from a deformable interface, (2) a plume head passing through an.interface, and (3) a plume head approaching the surface of the Earth. For the...