The output of gas and tephra from volcanoes is an inherently disorganized process that makes reliable flux estimates challenging to obtain. Continuous monitoring of gas flux has been achieved in only a few instances at subaerial volcanoes, but never for submarine volcanoes. Here we use the first sustained (yearlong) hydroacoustic...
During the last glacial period atmospheric carbon dioxide and temperature in Antarctica varied in a similar fashion on millennial time scales, but previous work indicates that these changes were gradual. In a detailed analysis of one event we now find that approximately half of the CO₂ increase that occurred during...
We investigate the freshwater composition of the shelf
and slope of the Arctic Ocean north of the New Siberian
Islands using geochemical tracer data (δ¹⁸O, Ba, and PO₄*)
collected following the extreme summer of 2007. We find
that the anomalous wind patterns that partly explained the sea
ice minimum at...
We estimate the depth of the 120°C isotherm by constructing crustal thermal gradients based on theoretical and observed conductive heat flux as a function of lithospheric age. We chose the 120°C isotherm because it is close to the upper limit for prokaryotic life, and therefore, the isotherm approximates the maximum...
It is widely accepted that plate divergence at mid-ocean ridges drives mantle flow, mantle melting, and the formation of new oceanic crust. However, many of the details of this process remain obscure because of the inaccessibility of the mantle to direct observation. Thus, geodynamic models are needed to provide insight...
Error in distributed temperature sensing (DTS) water temperature measurements may be introduced by contact of the fiber optic cable sensor with bed materials (e.g., seafloor, lakebed, streambed). Heat conduction from the bed materials can affect cable temperature and the resulting DTS measurements. In the Middle Fork John Day River, apparent...
Large rivers represent gateways for the transport of
terrigenous and anthropogenic material to the coastal ocean.
Here we document a ∼700 km2 recirculation or bulge associated
with the Columbia River plume that retains recently discharged
river water sufficiently to create a regional bioreactor.
Fueled by a fluvial nitrate source, this...
An interlaboratory study of Mg/Ca and Sr/Ca ratios in three commercially available carbonate reference
materials (BAM RS3, CMSI 1767, and ECRM 752-1) was performed with the participation of
25 laboratories that determine foraminiferal Mg/Ca ratios worldwide. These reference materials containing
Mg/Ca in the range of foraminiferal calcite (0.8 mmol/mol to...
Vailulu’u seamount is an active underwater volcano that marks the end of the Samoan hotspot trail (Hart et al., 2000). Vailulu’u has a simple conical morphology (Figure 1) with a largely enclosed volcanic crater at relatively shallow water depths, ranging from 590 m (highest point on the crater rim) to...
We present a new high-precision, high-resolution record of atmospheric methane from the West Antarctic Ice Sheet (WAIS) Divide ice core covering 1000–1800 C.E., a time period known as the late preindustrial Holocene (LPIH). The results are consistent with previous measurements from the Law Dome ice core, the only other high-resolution...