Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
John Pohlman, PhD
John Pohlman is a Research Chemist with the Woods Hole Coastal and Marine Science Center Gas Hydrates Project.
Science and Products
U.S. Geological Survey Gas Hydrates Project
Gas Hydrates- Climate and Hydrate Interactions
Gas Hydrates - Primer
Methane and carbon dioxide concentration data, environmental data, and calculations used to determine sea-air flux on the northern Greenland margin
Time-series measurements of acoustic intensity, flow, pressure, water level, conductivity, temperature, and dissolved oxygen collected in a flooded cave at Cenote Bang, Yucatan Peninsula, Tulum, Mexico from March 25, 2018 to August 1, 2018
Water column properties and temporal hydrologic and chemical records from flooded caves (Ox Bel Ha and Cenote Crustacea) within the coastal aquifer of the Yucatan Peninsula, Quintana Roo, from December 2013 to January 2015
Water column physical and chemical properties of Cenote Bang, a component of the Ox Bel Ha cave network within the subterranean estuary coastal aquifer of the Yucatan Peninsula, from December 2013 to January 2016
Comparison of methane concentration and stable carbon isotope data for natural samples analyzed by discrete sample introduction module - cavity ring down spectroscopy (DSIM-CRDS) and traditional methods
Geochemical data supporting investigation of solute and particle cycling and fluxes from two tidal wetlands on the south shore of Cape Cod, Massachusetts, 2012-19 (ver. 2.0, October 2022)
Vertical chemical profiles collected across haloclines in the water column of the Ox Bel Ha cave network within the coastal aquifer of the Yucatan Peninsula in January 2015 and January 2016
Temporal hydrologic and chemical records from the Ox Bel Ha cave network within the coastal aquifer of the Yucatan Peninsula, from January 2015 to January 2016
Data and calculations to support the study of the sea-air flux of methane and carbon dioxide on the West Spitsbergen margin in June 2014
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
The USGS and the University of Maryland’s Chesapeake Biological Laboratory conducted a study in the Chesapeake Bay to quantify greenhouse gas fluxes from the largest estuary in the U.S.
The USGS and the University of Maryland’s Chesapeake Biological Laboratory conducted a study in the Chesapeake Bay to quantify greenhouse gas fluxes from the largest estuary in the U.S.
The USGS Gas Hydrates Project analyzes the sediments that make up gas hydrate reservoirs in the Physical Properties Laboratory and manages the standalone Hydrate Pressure Core Analysis Laboratory (HyPrCAL) at the Woods Hole Coastal and Marine Science Center (WHCMSC) to study hydrate-bearing sediments in support of energy resources and geohazards research.
The USGS Gas Hydrates Project analyzes the sediments that make up gas hydrate reservoirs in the Physical Properties Laboratory and manages the standalone Hydrate Pressure Core Analysis Laboratory (HyPrCAL) at the Woods Hole Coastal and Marine Science Center (WHCMSC) to study hydrate-bearing sediments in support of energy resources and geohazards research.
Gas Hydrates Biogeochemistry Laboratory equipment and program staff.
Gas Hydrates Biogeochemistry Laboratory equipment and program staff.
Part of the Akumal coastline in Quintana Roo, Mexico, near where the Ox Bel Ha cave system is located.
Part of the Akumal coastline in Quintana Roo, Mexico, near where the Ox Bel Ha cave system is located.
John Pohlman (USGS), David Brankovits (USGS/WHOI) and Jake Emmert (MG) deploy acoustic devices in open water sinkhole (or cenote) prior to a 6-month long installation in the Yucatan Peninsula, Mexico cave
John Pohlman (USGS), David Brankovits (USGS/WHOI) and Jake Emmert (MG) deploy acoustic devices in open water sinkhole (or cenote) prior to a 6-month long installation in the Yucatan Peninsula, Mexico cave
Hydroacoustic observations reveal drivers of mixing and salinization of a karst subterranean estuary during intense precipitation
Terrebonne Basin northern Gulf of Mexico, 30 July-28 September 2023
Oxygenation of a karst subterranean estuary during a tropical cyclone: Mechanisms and implications for the carbon cycle
Barkley Canyon gas hydrates: A synthesis based on two decades of seafloor observation and remote sensing
USGS tools perform gas source analysis in the field
Northern Cascadia Margin gas hydrates — Regional geophysical surveying, IODP drilling leg 311, and cabled observatory monitoring
Contribution of deep-sourced carbon from hydrocarbon seeps to sedimentary organic carbon: Evidence from radiocarbon and stable isotope geochemistry
Discrete sample introduction module for quantitative and isotopic analysis of methane and other gases by cavity ring-down spectroscopy
Metabolic flexibility of aerobic methanotrophs under anoxic conditions in Arctic lake sediments
Ideas and perspectives: A strategic assessment of methane and nitrous oxide measurements in the marine environment
Focused fluid flow along the Nootka Fault Zone and continental slope, Explorer-Juan de Fuca plate boundary
Methane oxidation dynamics in a karst subterranean estuary
Science and Products
U.S. Geological Survey Gas Hydrates Project
Gas Hydrates- Climate and Hydrate Interactions
Gas Hydrates - Primer
Methane and carbon dioxide concentration data, environmental data, and calculations used to determine sea-air flux on the northern Greenland margin
Time-series measurements of acoustic intensity, flow, pressure, water level, conductivity, temperature, and dissolved oxygen collected in a flooded cave at Cenote Bang, Yucatan Peninsula, Tulum, Mexico from March 25, 2018 to August 1, 2018
Water column properties and temporal hydrologic and chemical records from flooded caves (Ox Bel Ha and Cenote Crustacea) within the coastal aquifer of the Yucatan Peninsula, Quintana Roo, from December 2013 to January 2015
Water column physical and chemical properties of Cenote Bang, a component of the Ox Bel Ha cave network within the subterranean estuary coastal aquifer of the Yucatan Peninsula, from December 2013 to January 2016
Comparison of methane concentration and stable carbon isotope data for natural samples analyzed by discrete sample introduction module - cavity ring down spectroscopy (DSIM-CRDS) and traditional methods
Geochemical data supporting investigation of solute and particle cycling and fluxes from two tidal wetlands on the south shore of Cape Cod, Massachusetts, 2012-19 (ver. 2.0, October 2022)
Vertical chemical profiles collected across haloclines in the water column of the Ox Bel Ha cave network within the coastal aquifer of the Yucatan Peninsula in January 2015 and January 2016
Temporal hydrologic and chemical records from the Ox Bel Ha cave network within the coastal aquifer of the Yucatan Peninsula, from January 2015 to January 2016
Data and calculations to support the study of the sea-air flux of methane and carbon dioxide on the West Spitsbergen margin in June 2014
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
Infographic showing how stormwater provides underwater caves with an influx of oxygen that is critical to supporting microorganisms—an integral part of the food web—and limiting the release of harmful greenhouse gases into the ocean and atmosphere.
The USGS and the University of Maryland’s Chesapeake Biological Laboratory conducted a study in the Chesapeake Bay to quantify greenhouse gas fluxes from the largest estuary in the U.S.
The USGS and the University of Maryland’s Chesapeake Biological Laboratory conducted a study in the Chesapeake Bay to quantify greenhouse gas fluxes from the largest estuary in the U.S.
The USGS Gas Hydrates Project analyzes the sediments that make up gas hydrate reservoirs in the Physical Properties Laboratory and manages the standalone Hydrate Pressure Core Analysis Laboratory (HyPrCAL) at the Woods Hole Coastal and Marine Science Center (WHCMSC) to study hydrate-bearing sediments in support of energy resources and geohazards research.
The USGS Gas Hydrates Project analyzes the sediments that make up gas hydrate reservoirs in the Physical Properties Laboratory and manages the standalone Hydrate Pressure Core Analysis Laboratory (HyPrCAL) at the Woods Hole Coastal and Marine Science Center (WHCMSC) to study hydrate-bearing sediments in support of energy resources and geohazards research.
Gas Hydrates Biogeochemistry Laboratory equipment and program staff.
Gas Hydrates Biogeochemistry Laboratory equipment and program staff.
Part of the Akumal coastline in Quintana Roo, Mexico, near where the Ox Bel Ha cave system is located.
Part of the Akumal coastline in Quintana Roo, Mexico, near where the Ox Bel Ha cave system is located.
John Pohlman (USGS), David Brankovits (USGS/WHOI) and Jake Emmert (MG) deploy acoustic devices in open water sinkhole (or cenote) prior to a 6-month long installation in the Yucatan Peninsula, Mexico cave
John Pohlman (USGS), David Brankovits (USGS/WHOI) and Jake Emmert (MG) deploy acoustic devices in open water sinkhole (or cenote) prior to a 6-month long installation in the Yucatan Peninsula, Mexico cave