Physical Scientist
Woods Hole Coastal and Marine Science Center
Email:
mcasso@usgs.gov
Office Phone:
508-457-2338
Fax:
508-457-2310
ORCID:
0000-0002-6990-9090
Location
Crawford Building
384 Woods Hole Road
Woods Hole
, MA
02543-1598
US
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Assessment of geochemical cycling within tidal wetlands and measurement of fluxes of dissolved and particulate constituents between wetlands and coastal water bodies are critical to evaluating ecosystem function, service, and status. The U.S. Geological Survey and collaborators collected surface water and porewater geochemical data from a tidal wetland located on the eastern shore of Sage Lot Pond in Mashpee, Massachusetts, within the Waquoit Bay National Estuarine Research Reserve, between 2012 and 2019. Additional porewater geochemical and field data from a tidal wetland on the eastern shore of Great Pond in East Falmouth, MA are also included. These data can be used to evaluate biogeochemical conditions and cycling...
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Groundwater data were collected in the spring and fall of 2008 from three sites representing different geological settings and biogeochemical conditions within the surficial glacial aquifer of Long Island, NY. Investigations were designed to examine the extent to which average vadose zone thickness in contributing watersheds controlled biogeochemical conditions and processes, including dissolved oxygen concentration (DO), oxidation-reduction potential (Eh), dissolved organic carbon concentration (DOC), and microbial dinitrogen (N2) production. Greatest N2 production was observed at the south shore of Long Island, which is characterized by a thin vadose zone, low DO and Eh, and relatively high DOC. Limited N2 production...
Categories: Data;
Types: Citation;
Tags: Geochemistry,
Great South Bay,
Hydrogeology,
Long Island Sound,
Long Island, NY, United States, All tags...
Manhasset Bay,
Northport Harbor,
Northport, NY, United States,
Patchogue, NY, United States,
Port Washington, NY, United States,
Water Resources,
climate change,
denitrification,
dissolved organic carbon,
dissolved oxygen,
environment,
excess air,
geoscientificInformation,
groundwater,
groundwater discharge,
hydrogeology,
membrane inlet mass spectrometry (MIMS),
nitrate,
oxygen content (water),
recharge temperature,
salinity,
tritium analysis,
vadose zone thickness,
water chemistry,
water pH, Fewer tags
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A critical question for assessing global greenhouse gas budgets is how much of the methane that escapes from seafloor cold seep sites to the overlying water column eventually crosses the sea-air interface and reaches the atmosphere. The issue is particularly important in Arctic Ocean waters since rapid warming there increases the likelihood that gas hydrate--an ice-like form of methane and water stable at particular pressure and temperature conditions within marine sediments--will break down and release its methane to the overlying ocean. Some researchers have even proposed the possibility of an Arctic methane catastrophe characterized by wholesale breakdown of gas hydrates in marine sediments and release of the...
Categories: Data;
Tags: Arctic Ocean,
Norway,
Prins Karls Forland,
Spitsbergen,
Svalbard, All tags...
carbon cycling,
carbon isotope analysis,
environment,
geoscientificInformation,
greenhouse gas flux,
marine chemistry,
methane seep,
ocean temperature,
ocean-atmosphere interaction,
oceanographic observations,
oceans,
sea-air gas flux,
seep and vent ecosystems,
seepage studies, Fewer tags
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A discrete sample introduction module (DSIM) was developed and interfaced to a cavity ring-down spectrometer to enable measurements of methane and CO2 concentrations and 13C values with a commercially available cavity ring-down spectrometer (CRDS). The DSIM-CRDS system permits the analysis of limited volume (5 - 100-ml) samples ranging six orders-of-magnitude from 100% analyte to the lower limit of instrument detection (2 ppm). We demonstrate system performance for methane by comparing concentrations and 13C results obtained by the DSIM and traditional methods for a variety of sample types, including low concentration (nanomolar) seawater and high concentration (> 90%) natural gas. The expansive concentration range...
Categories: Data;
Tags: Geochemistry,
Temperate Northern Atlantic,
Temperate Northern Pacific,
U.S. Geological Survey,
USGS, All tags...
biogeochemistry,
carbon cycle,
carbon cycling,
carbon dioxide,
carbon isotope analysis,
cavity ring-down spectroscopy,
eastern continental margin of India,
environment,
gas hydrate resources,
geochemical data,
geochemistry,
geochemistry,
isotope geochemistry,
marine chemistry,
methane,
methane hydrate,
northern Cascadia margin,
northern US Atlantic margin,
ocean characteristics,
oceanography,
oceans,
sediment geochemistry,
stable isotopes, Fewer tags
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Natural cave passages penetrating coastal aquifers in the Yucatan Peninsula (Quintana Roo, Mexico) were accessed to investigate how regional meteorology and hydrology control dissolved organic carbon and methane dynamics in karst subterranean estuaries, the region of aquifers where fresh and saline waters mix. Three field trips were carried out in December 2013, August 2014, and January 2015 to obtain 1) physicochemical and 2) geochemical data from the water column and 3) temporal records of water chemistry and hydrological parameters below and above the surface at three sites within the Ox Bel Ha cave (Cenote Jailhouse, Cenote Naach Wennen Ha, and Cenote Odyssey) and another cave (Cenote Crustacea). These efforts...
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