Browsing Earth Science by Title
Now showing items 17-32 of 32
-
Lg attenuation in northeast China using NECESSArray data
(2015)The 127 station NorthEast China Extended SeiSmic Array (NECESSArray) provides large quantities of high quality seismic data in northeast China that allow us to resolve lateral variations of Lg Q or crustal attenuation at ... -
Lithosphere versus asthenosphere mantle sources at the Big Pine Volcanic Field, California
(American Geophysical Union, 2012-06-27)[1] Here we report the first measurements of the H2O content of magmas and mantle xenoliths from the Big Pine Volcanic Field (BPVF), California, in order to constrain the melting process in the mantle, and the role of ... -
Lithospheric expression of cenozoic subduction, mesozoic rifting and the Precambrian Shield in Venezuela
(2015)We have combined surface wave tomography with Ps and Sp receiver-function images based on common-conversion-point (CCP) stacking to study the upper mantle velocity structure, particularly the lithosphere–asthenosphere ... -
Low wave speed zones in the crust beneath SE Tibet revealed by ambient noise adjoint tomography
(2014)We present a refined 3D crustal model beneath SE Tibet from ambient noise adjoint tomography. Different from ray-theory-based tomography, adjoint tomography in this study incorporates a spectral-element method (SEM) and ... -
Midinfrared third-harmonic generation from macroscopically aligned ultralong single-wall carbon nanotubes
(2013)We report the observation of strong third-harmonic generation from a macroscopic array of aligned ultralong single-wall carbon nanotubes (SWCNTs)with intensemidinfrared radiation. Through power-dependent experiments, we ... -
Missing Lead and High 3He/4He in Ancient Sulfides Associated with Continental Crust Formation
(2014-06-17)Major terrestrial reservoirs have Pb isotopes more radiogenic than the bulk silicate Earth. This requires a missing unradiogenic Pb reservoir, which has been argued to reside in the lower continental crust or dissolved in ... -
Nitrogen, biochar, and mycorrhizae: Alteration of the symbiosis and oxidation of the char surface
(2014)In some cases amending soil with biochar improves fertility, although the exact mechanisms through which biochar alters soil processes are not well understood. In other cases, however, biochar amendment can have no effect ... -
Pacific plate deformation from horizontal thermal contraction
(2014-08-15)The central approximation of plate tectonics is that the plates are rigid, which gives the theory its rigor and predictive power. Space geodetic measurements are consistent with the rigidity of stable plate interiors, but ... -
Pore size controls on the base of the methane hydrate stability zone in the Kumano Basin, offshore Japan
(2014)The base of the methane hydrate stability zone (MHSZ) in the Kumano Basin, offshore Japan, is marked by a bottom-simulating reflection (BSR) on seismic data. At Integrated Ocean Drilling Program Site C0002, which penetrates ... -
Ray-parameter based stacking and enhanced pre-conditioning for stable inversion of receiver function data
(2013-05-30)While inversion of seismic velocity from receiver function data could be instable due to its intrinsic non-linearity and non-uniqueness, improper stacking of receiver function could also introduce significant biases to ... -
Reactive Infiltration of MORB-Eclogite-Derived Carbonated Silicate Melt into Fertile Peridotite at 3GPa and Genesis of Alkalic Magmas
(2013-09-10)We performed experiments between two different carbonated eclogite-derived melts and lherzolite at 1375°C and 3 GPa by varying the reacting melt fraction from 8 to 50 wt %. The two starting melt compositions were (1) alkalic ... -
Relating vesicle shapes in pyroclasts to eruption styles
(Springer-Verlag, 2013)Vesicles in pyroclasts provide a direct record of conduit conditions during explosive volcanic eruptions. Although their numbers and sizes are used routinely to infer aspects of eruption dynamics, vesicle shape remains ... -
Simultaneous partitioning of silicon and oxygen into the Earth’s core during early Earth differentiation
(2013-01-16)Silicon and oxygen are potential light elements in the Earth’s core and may be involved in metal-silicate reactions at the present day core-mantle boundary. We have performed multianvil experiments at 25 GPa and 2770–3080K ... -
A Study of Cathodoluminescence and Trace Element Compositional Zoning in Natural Quartz from Volcanic Rocks: Mapping Titanium Content in Quartz
(Microscopy Society of America, 2012) -
Testing morphodynamic controls on the location and frequency of river avulsions on fans versus deltas: Huanghe (Yellow River), China
(2014)A mechanistic understanding of river avulsion location and frequency is needed to predict the growth of alluvial fans and deltas. The Huanghe, China, provides a rare opportunity to test emerging theories because its high ... -
Tests of fixity of the Indo-Atlantic hot spots relative to Pacific hot spots
(2014)Rates of inter-hot spot motion have been debated for decades. Herein we present updated predictions for the tracks of the Tristan da Cunha, Réunion, and Iceland hot spots assuming them to be fixed relative to Pacific hot ...
