RSS 1.0Geology and Geophysics (G&G)
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Scientists in the G&G Department seek knowledge of the structure, composition, and dynamics of the earth’s interior, the origin and evolution of the earth’s crust, controls on ocean and climate change on time scales of decades to 100 million years, and processes of mass and energy transfer at the land-sea interface.
Recent Submissions
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Tidal and thermal stresses drive seismicity along a major Ross Ice Shelf rift
(American Geophysical Union, 2019-05-23)Understanding deformation in ice shelves is necessary to evaluate the response of ice shelves to thinning. We study microseismicity associated with ice shelf deformation using nine broadband seismographs deployed near a ... -
Reconstructing atmospheric changes in Monsoon regions using eolian dust
(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2019-09)Mineral dust is generated in continental interiors and exported by winds to ocean basins, providing a sedimentary archive which is one of the few direct indicators we have of atmospheric circulation in the past. This archive ... -
Deep seismic structure across the southernmost Mariana trench: Implications for arc rifting and plate hydration
(American Geophysical Union, 2019-04-05)The southernmost Mariana margin lacks a mature island arc and thus differs significantly from the central‐north Mariana and Izu‐Bonin margins. This paper presents a new P wave velocity model of the crust and uppermost ... -
Atlantic circulation and ice sheet influences on upper South Atlantic temperatures during the last deglaciation
(American Geophysical Union, 2019-05-28)Atlantic Meridional Overturning Circulation (AMOC) disruption during the last deglaciation is hypothesized to have caused large subsurface ocean temperature anomalies, but records from key regions are not available to test ... -
Submarine giant pumice: A window into the shallow conduit dynamics of a recent silicic eruption.
(Springer, 2019-06-29)Meter-scale vesicular blocks, termed “giant pumice,” are characteristic primary products of many subaqueous silicic eruptions. The size of giant pumices allows us to describe meter-scale variations in textures and geochemistry ... -
Storm signatures in coastal ponds and marshes over the late Holocene
(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2019-09)Tropical cyclones pose a growing threat to coastal populations, especially as both populations and infrastructure are increasingly concentrated along the eastern coast of the United States. This thesis seeks to characterize ... -
Geophysical and geochemical constraints on submarine volcanic processes
(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2019-09)Submarine volcanic systems form new oceanic crust, host unique chemosynthetic ecosystems, concentrate rare metals, and provide a conduit for chemical transfer from the Earth's interior to hydrosphere. Although our understanding ... -
Mapping the lava deltas of the 2018 eruption of Kilauea Volcano
(Oceanography Society, 2019-03) -
SUBSEA 2018 expedition to Lo'ihi seamount, Hawai'i
(Oceanography Society, 2019-03) -
Aquifer systems extending far offshore on the US Atlantic margin.
(Nature Research, 2019-06-18)Low-salinity submarine groundwater contained within continental shelves is a global phenomenon. Mechanisms for emplacing offshore groundwater include glacial processes that drove water into exposed continental shelves ... -
Significance of perylene for source allocation of terrigenous organic matter in aquatic sediments.
(American Chemical Society, 2019-06-19)Perylene is a frequently abundant, and sometimes the only polycyclic aromatic hydrocarbon (PAH) in aquatic sediments, but its origin has been subject of a longstanding debate in geochemical research and pollutant forensics ... -
Dissolved organic radiocarbon in the central Pacific Ocean
(American Geophysical Union, 2019-05-02)We report marine dissolved organic carbon (DOC) concentrations, and DOC ∆14C and δ13C values in seawater collected from the central Pacific. Surface ∆14C values are low in equatorial and polar regions where upwelling occurs ... -
Distribution of crustal melt bodies at the hot spot-influenced section of the Galapagos Spreading Centre from seismic reflection images
(American Geophysical Union, 2019-04-29)Accretion of the lower crust at mid‐ocean ridges is a debated topic, with modern seismic observations pointing to a complex magmatic system that includes an axial multisill system of middle‐ and lower‐crustal melt lenses ... -
Regional Pliocene exhumation of the Lesser Himalaya in the Indus drainage
(European Geosciences Union, 2019-05-16)New bulk sediment Sr and Nd isotope data, coupled with U–Pb dating of detrital zircon grains from sediment cored by the International Ocean Discovery Program in the Arabian Sea, allow the reconstruction of erosion in the ... -
The mighty Susquehanna-extreme floods in Eastern North America during the past two millennia
(American Geophysical Union, 2019-02-19)The hazards posed by infrequent major floods to communities along the Susquehanna River and the ecological health of Chesapeake Bay remain largely unconstrained due to the short length of streamgage records. Here we develop ... -
Big-picture geochemistry from microanalyses - my four-decade odyssey in sims
(European Association of Geochemistry, 2019-04)Secondary Ion Mass Spectrometry (SIMS) is now a well established analytical technique in geochemistry. Its developmental history goes back to the 1970s. Here, I tell the story of how I got involved in its applications to ... -
"Petit spot" rejuvenated volcanism superimposed on plume-derived Samoan shield volcanoes: Evidence from a 645-m drill core from Tutuila Island, American Samoa
(American Geophysical Union, 2019-02-13)In 2015 a geothermal exploration well was drilled on the island of Tutuila, American Samoa. The sample suite from the drill core provides 645 m of volcanic stratigraphy from a Samoan volcano, spanning 1.45 million years ... -
A comprehensive global oceanic dataset of helium isotope and tritium measurements.
(Copernicus Publications, 2019-04-05)Tritium and helium isotope data provide key information on ocean circulation, ventilation, and mixing, as well as the rates of biogeochemical processes and deep-ocean hydrothermal processes. We present here global oceanic ... -
Electrical investigation of natural lawsonite and application to subduction contexts
(American Geophysical Union, 2019-02-27)We report an experimental investigation of the electrical properties of natural polycrystalline lawsonite from Reed Station, CA. Lawsonite represents a particularly efficient water reservoir in subduction contexts, as it ... -
Azimuthal seismic anisotropy of 70-ma Pacific-plate upper mantle.
(American Geophysical Union, 2019-01-28)Plate formation and evolution processes are predicted to generate upper mantle seismic anisotropy and negative vertical velocity gradients in oceanic lithosphere. However, predictions for upper mantle seismic velocity ...
