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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Heat flux from a vapor-dominated hydrothermal field beneath Yellowstone Lake
(American Geophysical Union, 2021-05-14)We report results from 149 heat flux measurements made over an ∼2-year interval at sites in and around a vapor-dominated geothermal field located at water depths of ∼100–120 m in Yellowstone Lake, Wyoming. Measurements of ... -
Dissolved organic radiocarbon in the eastern Pacific and Southern Oceans
(American Geophysical Union, 2021-05-24)We report marine dissolved organic carbon (DOC) concentrations, and DOC Δ14C and δ13C values in seawater collected from the Southern Ocean and eastern Pacific GOSHIP cruise P18 in 2016/2017. The aging of 14C in DOC in ... -
Evidence for decreased precipitation variability in the Yucatán Peninsula during the mid-Holocene
(American Geophysical Union, 2021-05-06)The Yucatán Peninsula (YP) has a complex hydroclimate with many proposed drivers of interannual and longer-term variability, ranging from coupled ocean–atmosphere processes to frequency of tropical cyclones. The mid-Holocene, ... -
Remote and local drivers of Pleistocene South Asian summer monsoon precipitation: a test for future predictions
(American Association for the Advancement of Science, 2021-06-04)South Asian precipitation amount and extreme variability are predicted to increase due to thermodynamic effects of increased 21st-century greenhouse gases, accompanied by an increased supply of moisture from the southern ... -
Postmelting hydrogen enrichment in the oceanic lithosphere
(American Association for the Advancement of Science, 2021-06-09)The large range of H2O contents recorded in minerals from exhumed mantle rocks has been challenging to interpret, as it often records a combination of melting, metasomatism, and diffusional processes in spatially isolated ... -
Biophysical controls of marsh soil shear strength along an estuarine salinity gradient
(European Geosciences Union, 2021-05-25)Sea-level rise, saltwater intrusion, and wave erosion threaten coastal marshes, but the influence of salinity on marsh erodibility remains poorly understood. We measured the shear strength of marsh soils along a salinity ... -
Impacts of multiple stressors on a benthic foraminiferal community: a long-term experiment assessing response to ocean acidification, hypoxia and warming
(Frontiers Media, 2021-04-22)Ocean chemistry is changing as a result of human activities. Atmospheric carbon dioxide (CO2) concentrations are increasing, causing an increase in oceanic pCO2 that drives a decrease in oceanic pH, a process called ocean ... -
On the relationship between palaeomagnetic secular variation and excursions-records from MIS 8-ODP leg 172
(Oxford University Press, 2020-11-21)Palaeomagnetic secular variation (PSV) and excursion data obtained across MIS 8 (243–300 ka) from the western North Atlantic Ocean ODP (Ocean Drilling Program) sites 1060–1063 show composite high-resolution PSV records ... -
Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments
(American Association for the Advancement of Science, 2021-05-26)Oceanic deoxygenation is increasingly affecting marine ecosystems; many taxa will be severely challenged, yet certain nominally aerobic foraminifera (rhizarian protists) thrive in oxygen-depleted to anoxic, sometimes ... -
Inferring the thermomechanical state of the lithosphere using geophysical and geochemical observables
(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2021-09)This thesis focuses on interpreting geophysical and geochemical observables in terms of the thermomechanical state of the lithosphere. In Chapter 1, I correlate lower crustal rheology with seismic wave speed. Compositional ... -
Global ocean sediment composition and burial flux in the deep sea
(American Geophysical Union, 2021-03-21)Quantitative knowledge about the burial of sedimentary components at the seafloor has wide-ranging implications in ocean science, from global climate to continental weathering. The use of 230Th-normalized fluxes reduces ... -
Halogen (F, Cl) concentrations and Sr-Nd-Pb-B isotopes of the basaltic andesites from the southern Okinawa Trough: implications for the recycling of subducted serpentinites
(American Geophysical Union, 2021-03-12)Serpentinites are increasingly recognized as playing an important role in the global geochemical cycle. However, discriminating the contributions of serpentinites to arc magmas from those of other subduction components is ... -
A new middle to late Jurassic Geomagnetic Polarity Time Scale (GPTS) from a multiscale marine magnetic anomaly survey of the Pacific Jurassic Quiet Zone
(American Geophysical Union, 2021-01-21)The Geomagnetic Polarity Time Scale (GPTS) provides a basis for the geological timescale, quantifies geomagnetic field behavior, and gives a time framework for geologic studies. We build a revised Middle to Late Jurassic ... -
Event-dominated transport, provenance, and burial of organic carbon in the Japan Trench
(Elsevier, 2021-03-24)The delivery of organic carbon (OC) to the ocean's deepest trenches in the hadal zone is poorly understood, but may be important for the carbon cycle, contain crucial information on sediment provenance and event-related ... -
1,050 years of hurricane strikes on Long Island in the Bahamas
(American Geophysical Union, 2016-02-16)Sedimentary records of past hurricane activity indicate centennial-scale periods over the past millennium with elevated hurricane activity. The search for the underlying mechanism behind these active hurricane periods is ... -
Radiocarbon investigation of the big baobab of Outapi, Namibia
(Studia Chemia, 2021-03-31)The article reports the AMS (accelerator mass spectrometry) radiocarbon dating results of the Big baobab of Outapi, which is the largest African baobab of Outapi, Namibia. The investigation of this monumental baobab revealed ... -
Offshore freshened groundwater in continental margins
(American Geophysical Union, 2020-11-20)First reported in the 1960s, offshore freshened groundwater (OFG) has now been documented in most continental margins around the world. In this review we compile a database documenting OFG occurrences and analyze it to ... -
Comparison of oyster aquaculture methods and their potential to from coastal ecosystems
(Frontiers Media, 2021-03-24)Coastal ecosystems are impacted by excessive nutrient inputs that cause degradation of water quality and impairments of ecosystem functioning. Regulatory and management efforts to enhance nutrient export from coastal ... -
Tectonic controls on block rotation and sheeted sill emplacement in the Xigaze Ophiolite (Tibet): the construction mode of slow-spreading and ultraslow-spreading oceanic crusts
(American Geophysical Union, 2021-01-28)The internal structure of oceanic crusts is not well understood due to the limitation of deep drilling. However, that of ophiolites, i.e., on-land ancient analogs of oceanic lithosphere, could be precisely mapped and ... -
Influence of hydraulic connectivity on carbon burial efficiency in Mackenzie Delta lake sediments
(American Geophysical Union, 2021-02-02)The Arctic is undergoing accelerated changes in response to ongoing modifications to the climate system, and there is a need for local to regional scale records of past climate variability in order to put these changes ...
