[1] We present results from a wide-angle seismic refraction survey over Shatsky Rise, a large oceanic plateau in the northwestern Pacific. A new Monte Carlo sampling scheme is developed to explore comprehensively the model space of crustal velocity structure by joint refraction and reflection seismic tomography. The new scheme, which is founded on the notion of adaptive importance sampling, is ...

a r t i c l e i n f o A classical problem in seismic tomography is the trade-off between a discontinuity location and the velocity of the medium. For that reason, crustal tomography and Pn tomography are typically done separately by isolating first-arriving Pg and Pn waves. Although this avoids the contamination of secondary arrivals because of the existence of the Moho, lots of good data are d...

Multi-element abundances in twenty-four samples from the Serra Geral continental flood basalt system (Parana Basin) were determined by INAA to assess the trace element signature of primary magmatric sources. Isotopic Sr and Nd data were obtained on a 24-sample composite and three individual samples of the suite to constrain the influences of older enriched material. Twenty basaltic samples have...

S U M M A R Y The geographical distribution of the (1981–2005) seismicity in southern California forms a ±150 km broad zone adjacent to the Pacific–North America plate boundary, ranging from depths of ∼1–∼30 km, with the bulk of the focal depths in the range of 2–12 km. The distribution of the seismicity that includes both mainshock–aftershock sequences and background events is affected by both...

[1] Samples of aerosols from the marine boundary layer of the Arctic Ocean were collected aboard the R/V Xuelong during summer on the Second Chinese Arctic Research Expedition (July–September 2003). Synchrotron radiation X-ray fluorescence (SR-XRF) was used to determine chemical compositions of aerosol particles. Multivariate analysis of the SR-XRF data resolved a number of components (factors)...

Kimberlite and lamproite magmas sample diamonds deep in the mantle and depending on the rapidity of ascent and emplacement, bring them to the surface in various states of preservation. Economic diamond deposits are usually hosted in primary kimberlite and lamproite diatremes that intrude Archean crustal provinces. Placer deposits of diamonds that are sourced in kimberlite from Archean crustal p...

[1] We use neural networks to find 1-dimensional marginal probability density functions (pdfs) of global crustal parameters. The information content of the full posterior and prior pdfs can quantify the extent to which a parameter is constrained by the data. We inverted fundamental mode Love and Rayleigh wave phase and group velocity maps for pdfs of crustal thickness and independently of verti...

Spatial and temporal patterns of exhumation are inextricably linked to patterns of crustal deformation because crustal deformation drives rock uplift. A new interpretation of a segment of the Pacific-North America transpressional plate boundary in southern California is analyzed in the context of crustal shortening, rock uplift, and exhumation. Deformation is partitioned between two structural ...

Methods Following a standardized physical exam using sterile gloves and a sterile stethoscope, bacterial contamination of the following regions were assessed using contact plates: stethoscope diaphragm, stethoscope tube, fingertips, thenar region, hypothenar region and back of physician’s dominant hand. Total aerobic colony count (ACC) were determined on digital photographs using a counting tool.