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Neil C Terry, PhD

Neil C Terry, PhD is a a research hydrologist at the USGS New York Water Science Center.

I am a research hydrologist at the USGS New York Water Science Center, where I specialize in near-surface geophysics, modeling, and water-related projects.  Particular focus areas include groundwater quality monitoring, hydrogeological characterization, contaminant detection, and groundwater-surface water interactions.  I also lead and support software/methods development efforts, specifically focusing on linking electrical geophysical measurements with soil and hydrogeological properties.

Prior to joining the USGS, my PhD work at Rutgers University centered around hydrogeophysical approaches to characterize and study processes occurring in wetlands - particularly carbon gas cycling in peatlands.  During this time, I also participated in critical zone characterization and archaeological studies, among other projects.  My MS work at the University at Buffalo primarily involved linking geophysical data to soil moisture distributions through coupled geophysical and unsaturated flow models in a Bayesian framework.

Professional Experience

  • A research hydrologist at the USGS New York Water Science Center.

Education and Certifications

  • PhD at Rutgers University

  • MS at the University of Buffalo

Science and Products

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Scientist operates equipment console while towing GPR on ice

What does groundwater have to do with ice in Alaska?

USGS scientists are working alongside university researchers in Alaska to understand how groundwater and permafrost conditions change over time due to seasonal variations and climate change. Changes in permafrost can pose a threat to built infrastructure (like roads, homes, and pipelines) and to valued ecological resources that provide important habitats for wildlife.
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Water Resources Mission Area
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What does groundwater have to do with ice in Alaska?

USGS scientists are working alongside university researchers in Alaska to understand how groundwater and permafrost conditions change over time due to seasonal variations and climate change. Changes in permafrost can pose a threat to built infrastructure (like roads, homes, and pipelines) and to valued ecological resources that provide important habitats for wildlife.
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Filter Total Items: 21

Floating Transient Electromagnetic Survey Data from the Columbia River near Hanford, WA

This data release contains motorboat-towed floating transient electromagnetic data collected from the Columbia River near Hanford WA.  Data were collected using a ~16 foot (4.9 meters) outboard motorboat during two field campaigns: July 2021 and April 2022. In total, several hundred linear kilometers of data were collected from a reach of the Columbia that extends from approximately Vernita Bridge
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New York Water Science Center

Floating Electromagnetic Surveys from the Lower Delaware River Basin

Electromagnetic (EM) geophysical methods provide information about the bulk electrical conductivity of the subsurface. EM data has been widely used to investigate aquifers and geologic structures. In the following study, the United States Geological Survey conducted a boat-towed, waterborne transient electromagnetic (FloaTEM) survey to examine conductivity within the subsurface of the main Delawar
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Water Resources Mission Area

Geophysical and Other Data From an Irrigation Monitoring Experiment at Haddam Meadows, CT, July 2019

An irrigation monitoring experiment was performed in Haddam Meadows State Park, Connecticut, on July 16, 2019. Prior to this experiment, ground penetrating radar (GPR), frequency domain electromagnetics (FDEM), and electrical resistivity tomography (ERT) geophysical data were collected over a 20 meter by 10-meter grid to provide baseline information. A vertical soil moisture probe was installed in
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New York Water Science Center

Main channel river water temperature collected along the East Branch, West Branch, and mainstem Delaware River down to Lordville near Handcock, NY, USA in summer 2021

The Upper Delaware River is a unique example of an aquatic system where summer river temperature is actively managed for ecological purposes. River temperature at the mainstem Delaware River at Lordville, NY gage (USGS 01427207) is targeted to remain below 25 degrees C, with warm events potentially mitigated via directed upstream reservoir releases, a process guided by predictive tools. These dire
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Water Resources Mission Area

Stream Temperature, Dissolved Radon, and Stable Water Isotope Data Collected along Headwater Streams in the Upper Neversink River Watershed, NY, USA (ver. 2.0, April 2023)

This data release contains three data types that could potentially be used to infer spatiotemporal variability in groundwater discharge processes, along with other research and monitoring purposes: 1) Temporally continuous stream channel water temperature and adjacent streambank air temperature time series data (generally starting November 2020) as well as limited temperature data from May to Octo
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Water Resources Mission Area, New York Water Science Center

Waterborne Gradient Self-potential, Temperature, and Conductivity Logging of the Upper part of the Delaware River between Hancock and Port Jervis, New York, June-July 2021

This data release contains waterborne gradient self-potential (SP), surface-water temperature, surface-water conductivity and specific conductance, and surface-water nitrate concentration data measured continuously in the upper part of the Delaware River along approximately 123 kilometers (km) between Hancock and Port Jervis, New York. All of the data were measured from a kayak between June 27 and
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Oklahoma-Texas Water Science Center, Pennsylvania Water Science Center

Passive seismic (HVSR) data from Fountain Creek, CO

A total of 119 passive seismic soundings were collected with Tromino (MoHo s.r.l.) 3-axis seismometers in the Fountain Creek area to partially refine alluvial aquifer thickness (depth to bedrock) estimates, particularly over known or suspected paleochannels. Data were collected during June 21-24, 2021 with a team of 4-5 people, each equipped with a Tromino Blu or Tromino 3G passive seismometer.
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New York Water Science Center

Frequency domain electromagnetic induction (FDEM) geophysical data collected near the Agashashok River in the Noatak National Preserve, AK

Frequency domain electromagnetic induction (FDEM) data were collected in September 2016 near the Agashashok River and its tributaries, within the Noatak National Preserve near Kotzebue, AK to aid in local permafrost mapping. Data were collected with a GEM-2 instrument (1.6 m coil separation, Geophex, Ltd.); a broadband sensor that measures the bulk conductivity and magnetic susceptibility of the s
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New York Water Science Center

Selected borehole geophysical logs from three contaminant sites in California, Wisconsin, and New Jersey

Borehole geophysical logs were collected to characterize bedrock aquifers at three contamination sites located in California, Wisconsin, and New Jersey. The data were collected by the U.S. Geological Survey (USGS) and the University of Guelph from 2014 to 2015 as part of the U.S. Department of Defense Strategic Environmental Research and Development Program (SERDP) and Environmental Security Techn
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Water Resources Mission Area

Depth to bedrock determined from passive seismic measurements, Neversink River watershed, NY (USA)

This data release documents streambed sediment thickness in the Neversink watershed (NY) as determined by field observations and HVSR passive seismic measurements, and were collected as an extension of a previous data set collected in the same watershed (see Associated Items). These measurements were made between May 17, 2021 and May 21, 2021 using MOHO Tromino three-component seismometers (MOHO,
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New York Water Science Center

Data used to estimate groundwater salinity above the Montebello oil field (California, USA)

This release contains borehole geophysical electrical log data (elogs), total dissolved solids sample data (TDS), and geostatistical program files used to estimate the salinity distribution in groundwater above and in the vicinity of the Montebello Oil Field, located near Los Angeles, California, USA. Original data are drawn from a variety of publicly available sources and are combined here for us
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Water Resources Mission Area

Near-surface geophysical data collected along French Gulch near Breckenridge, Colorado, USA, September 2020

Near-surface geophysical surveys were completed in September 2020 in a mine-affected drainage near Breckenridge, Colorado, known as French Gulch. The study area was along a 0.3 mile (0.5 kilometer [km]) reach of French Gulch, approximately 2 river miles upstream from its confluence with the Blue River. This data release presents data from three geophysical surveys that used fiber-optic distributed
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Colorado Water Science Center
Photo of geophysical equipment mounted on a drone sitting on a launchpad, with wetland open water and grasses in background
USGS conducts ground-penetrating radar survey to map peat
USGS conducts ground-penetrating radar survey to map peat
Photo of geophysical equipment mounted on a drone sitting on a launchpad, with wetland open water and grasses in background

USGS conducts ground-penetrating radar survey to map peat

USGS conducts ground-penetrating radar survey to map peat

USGS recently tested ground-penetrating radar (GPR) on a drone for mapping peat thickness and extent. This work is part of a collaboration with Florida Atlantic University to study and locate large carbon gas emissions from peat soils in the swampy wetlands of the Everglades in Florida.

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Water Resources, New York Water Science Center
Photo of geophysical equipment mounted on a drone sitting on a launchpad, with wetland open water and grasses in background

USGS conducts ground-penetrating radar survey to map peat

USGS conducts ground-penetrating radar survey to map peat

USGS recently tested ground-penetrating radar (GPR) on a drone for mapping peat thickness and extent. This work is part of a collaboration with Florida Atlantic University to study and locate large carbon gas emissions from peat soils in the swampy wetlands of the Everglades in Florida.

By
Water Resources, New York Water Science Center
Photo of equipment mounted on a drone sitting on a launchpad. In the background, a scientist is sitting next to a van.
USGS scientist prepares drone ground-penetrating radar for peat mapping
USGS scientist prepares drone ground-penetrating radar for peat mapping
Photo of equipment mounted on a drone sitting on a launchpad. In the background, a scientist is sitting next to a van.

USGS scientist prepares drone ground-penetrating radar for peat mapping

USGS scientist prepares drone ground-penetrating radar for peat mapping

USGS recently tested ground-penetrating radar (GPR) on a drone for mapping peat thickness and extent. This work is part of a collaboration with Florida Atlantic University to study and locate large carbon gas emissions from peat soils in the swampy wetlands of the Everglades in Florida.

By
Water Resources, New York Water Science Center
Photo of equipment mounted on a drone sitting on a launchpad. In the background, a scientist is sitting next to a van.

USGS scientist prepares drone ground-penetrating radar for peat mapping

USGS scientist prepares drone ground-penetrating radar for peat mapping

USGS recently tested ground-penetrating radar (GPR) on a drone for mapping peat thickness and extent. This work is part of a collaboration with Florida Atlantic University to study and locate large carbon gas emissions from peat soils in the swampy wetlands of the Everglades in Florida.

By
Water Resources, New York Water Science Center
Filter Total Items: 16

Advancing subsurface investigations beyond the borehole with passive seismic horizontal-to-vertical spectral ratio and electromagnetic geophysical methods at transportation infrastructure sites in New Hampshire

The U.S. Geological Survey (USGS), in cooperation with the New Hampshire Department of Transportation (NHDOT), surveyed transportation infrastructure sites using rapidly deployable geophysical methods to assess benefits added to a comprehensive site characterization with traditional geotechnical techniques. Horizontal-to-vertical spectral-ratio (HVSR) passive-seismic and electromagnetic-induction
Authors
James Degnan, Krystle Pelham, Neil Terry, Sydney M. Welch, Carole D. Johnson
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Water Resources Mission Area, New England Water Science Center

Paired Air and Stream Temperature Analysis (PASTA) to evaluate groundwater influence on streams

Groundwater is critical for maintaining stream baseflow and thermal stability; however, the influence of groundwater on streamflow has been difficult to evaluate at broad spatial scales. Techniques such as baseflow separation necessitate streamflow records and do not directly indicate whether groundwater inflow may be sourced from more dynamic shallow flowpaths. We present a web tool application P
Authors
Danielle K. Hare, Susanne A. Benz, Barret L. Kurylyk, Zachary Johnson, Neil Terry, Ashley M. Helton
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Ecosystems Mission Area, Water Resources Mission Area, Eastern Ecological Science Center, New York Water Science Center

Field evaluation of semi-automated moisture estimation from geophysics using machine learning

Geophysical methods can provide three-dimensional (3D), spatially continuous estimates of soil moisture. However, point-to-point comparisons of geophysical properties to measure soil moisture data are frequently unsatisfactory, resulting in geophysics being used for qualitative purposes only. This is because (1) geophysics requires models that relate geophysical signals to soil moisture, (2) geoph
Authors
Neil Terry, F.D. Day-Lewis, John W. Lane, Carole D. Johnson, Dale Werkema
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Water Resources Mission Area, New York Water Science Center

Interaction of a legacy groundwater contaminant plume with the Little Wind River from 2015 through 2017, Riverton Processing site, Wyoming

The Riverton Processing site was a uranium mill 4 kilometers southwest of Riverton, Wyoming, that prepared uranium ore for nuclear reactors and weapons from 1958 to 1963. The U.S. Department of Energy completed surface remediation of the uranium tailings in 1989; however, groundwater below and downgradient from the tailings site and nearby Little Wind River was not remediated. Beginning in 2010, a
Authors
David L. Naftz, Christopher C. Fuller, Robert L. Runkel, John Solder, W. Payton Gardner, Neil Terry, Martin A. Briggs, Terry M. Short, Daniel J. Cain, William L Dam, Patrick A. Byrne, James R. Campbell
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Water Resources Mission Area, Wyoming-Montana Water Science Center

Geostatistical mapping of salinity conditioned on borehole logs, Montebello Oil Field, California

We present a geostatistics-based stochastic salinity estimation framework for the Montebello Oil Field that capitalizes on available total dissolved solids (TDS) data from groundwater samples as well as electrical resistivity (ER) data from borehole logging. Data from TDS samples (n = 4924) was coded into an indicator framework based on falling below four selected thresholds (500, 1000, 3000, and
Authors
Neil Terry, Frederick Day-Lewis, Matthew K. Landon, Michael Land, Jennifer S. Stanton, John W. Lane
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Water Resources Mission Area, California Water Science Center, New England Water Science Center

Beware of spatial autocorrelation when applying machine learning algorithms to borehole geophysical logs

Although many of the algorithms now considered to be machine learning algorithms (MLAs) have existed for nearly a century (e.g., Rosenblatt 1958), interest in MLAs has recently increased exponentially for solving data-driven problems across a variety of fields due to the expanded availability of large, complex datasets that may be difficult to interrogate using other methods, increases in computin
Authors
Neil Terry, Carole D. Johnson, Frederick Day-Lewis, Beth L. Parker, Lee D. Slater
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Water Resources Mission Area, New York Water Science Center

Aufeis fields as novel groundwater-dependent ecosystems in the arctic cryosphere

River aufeis (ow′ fīse) are widespread features of the arctic cryosphere. They form when river channels become locally restricted by ice, resulting in cycles of water overflow and freezing and the accumulation of ice, with some aufeis attaining areas of ~ 25 + km2 and thicknesses of 6+ m. During winter, unfrozen sediments beneath the insulating ice layer provide perennial groundwater‐habitat that
Authors
Alexander D. Huryn, M. Gooseff, P. Hendrickson, Martin A. Briggs, K. Tape, Neil Terry
By
Water Resources Mission Area

Exploring the potential of ground-penetrating radar (GPR) to measure the extent of chronic disturbance in peatlands: Examples from acid mine drainage and peat fire

Peatlands are accumulations of partially decayed organic soil that cover approximately 3% of Earth’s surface and have been shown to serve essential environmental and ecological functions such as sequestering carbon, purifying water, and providing habitat for organisms. However, peatlands are threatened by pressures from agriculture, urban development, mining, and climate change. Geophysical method
Authors
Neil Terry, Robert L. Runkel, Dale D. Werkema, Elizabeth Rutila, Xavier Comas, Matthew Warren, Agus Kristiyono, Daniel Murdiyarso
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Water Resources Mission Area

Characterizing the diverse hydrogeology underlying rivers and estuaries using new floating transient electromagnetic methodology

The hydrogeology below large surface water features such as rivers and estuaries is universally under-informed at the long reach to basin scales (tens of km+). This challenge inhibits the accurate modeling of fresh/saline groundwater interfaces and groundwater/surface water exchange patterns at management-relevant spatial extents. Here we introduce a towed, floating transient electromagnetic (TEM)
Authors
John W. Lane, Martin A. Briggs, PK Maurya, Eric A. White, JB Pedersen, Esben Auken, Neil Terry, Burke J. Minsley, Wade Kress, Denis R. LeBlanc, Ryan F. Adams, Carole D. Johnson
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Water Resources Mission Area, New England Water Science Center, Lower Mississippi-Gulf Water Science Center, Geology, Geophysics, and Geochemistry Science Center

Seasonal subsurface thaw dynamics of an aufeis feature inferred from geophysical methods

Aufeis are sheets of ice unique to cold regions that originate from repeated flooding and freezing events during the winter. They have hydrological importance associated with summer flows and possibly winter insulation, but little is known about the seasonal dynamics of the unfrozen sediment layer beneath them. This layer may support perennial groundwater flow in regions with otherwise continuous
Authors
Neil Terry, Elliot Grunewald, Martin A. Briggs, Michael Gooseff, Alexander D. Huryn, M. Andy Kass, Ken Tape, Patrick Hendrickson, John W. Lane
By
Water Resources Mission Area

Controls on spatial and temporal variations of brine discharge to the Dolores River in the Paradox Valley, Colorado, 2016–18

The Paradox Valley in southwestern Colorado is a collapsed anticline formed by movement of the salt-rich Paradox Formation at the core of the anticline. The salinity of the Dolores River, a tributary of the Colorado River, increases substantially as it crosses the valley because of discharge of brine-rich groundwater derived from the underlying salts. Although the brine is naturally occurring, it
Authors
Alisa Mast, Neil Terry
By
Water Resources Mission Area, Colorado Water Science Center

Geophysical mapping of plume discharge to surface water at a crude oil spill site: Inversion versus machine learning

The interpretation of geophysical survey results to answer hydrologic, engineering, and geologic questions is critical to diverse problems for management of water, energy, and mineral resources. Although geophysical images provide valuable qualitative insight into subsurface architecture and conditions, translating geophysical images into quantitative information (e.g., saturation, concentration,
Authors
Neil Terry, Frederick D. Day-Lewis, John W. Lane, Jared J. Trost, Barbara A. Bekins
By
Water Resources Mission Area

Non-USGS Publications**

Terry, N. and Slater, L. ( 2017), Gas bubble size estimation in peat soils from EM wave scattering observed with ground penetrating radar, Water Resour. Res., 53, 2755– 2769, doi:10.1002/2016WR019783.
Day-Lewis, F. D., Slater, L. D., Robinson, J., Johnson, C. D., Terry, N., and Werkema, D. (2017), An overview of geophysical technologies appropriate for characterization and monitoring at fractured-rock sites, Journal of Environmental Management, 204, 709-720, doi: https://doi.org/10.1016/j.jenvman.2017.04.033.
Comas, X., Terry, N., Hribljan, J. A., Lilleskov, E. A., Suarez, E., Chimner, R. A., and Kolka, R. K. ( 2017), Estimating belowground carbon stocks in peatlands of the Ecuadorian páramo using ground‐penetrating radar (GPR), J. Geophys. Res. Biogeosci., 122, 370– 386, doi:10.1002/2016JG003550.
Terry, N., Slater, L., Comas, X., Reeve, A. S., Schäfer, K. V. R., and Yu, Z. ( 2016), Free phase gas processes in a northern peatland inferred from autonomous field‐scale resistivity imaging, Water Resour. Res., 52, 2996– 3018, doi:10.1002/2015WR018111.
Comas, X., Terry, N., Slater, L., Warren, M., Kolka, R., Kristiyono, A., Sudiana, N., Nurjaman, D., and Darusman, T.: Imaging tropical peatlands in Indonesia using ground-penetrating radar (GPR) and electrical resistivity imaging (ERI): implications for carbon stock estimates and peat soil characterization, Biogeosciences, 12, 2995–3007, https://doi.org/10.5194/bg-12-2995-2015, 2015.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

RDAVT

RDAVT.r is an R Shiny-based app used to estimate immobile porosity, mobile porosity, and the mass transfer rate coefficient in dual-domain porosity media. The app allows for interactive fitting of the fluid versus bulk conductivity hysteresis curve from electrical tracer experiments using a semi-analytic graphical approach.
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New York Water Science Center

FLASH-R (Flow-Log Analysis of Single Holes)

FLASH-R (Flow-Log Analysis of Single Holes) is an R app for the analysis of borehole vertical flow logs to estimate fracture (or layer) transmissivities and far-field hydraulic heads. This app is a new version of the FLASH spreadsheet tool by Day-Lewis et al. (2011) . The program is written in R, an open-source environment. All previous features have been retained and new features incorporated i
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Water Resources Mission Area

FLASH-R: Flow-Log Analysis of Single Holes

FLASH-R (Flow-Log Analysis of Single Holes) is an R app for the analysis of borehole vertical flow logs to estimate fracture (or layer) transmissivities and far-field hydraulic heads.

By
Water Resources Mission Area

MoisturEC

MoisturEC is an R-based GUI used to combine electrical conductivity (EC) data with point moisture measurements for an updated moisture estimate capitalizing on the accuracy of point moisture measurements and the spatial coverage of EC data.
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Water Resources Mission Area

MoisturEC: R-based GUI to combine electrical conductivity data with point moisture measurements

MoisturEC is an R-based GUI used to combine electrical conductivity (EC) data with point moisture measurements for an updated moisture estimate capitalizing on the accuracy of point moisture measurements and the spatial coverage of EC data. 

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Water Resources Mission Area

Scenario Evaluator for Electrical Resistivity (SEER) Survey Pre-Modeling Tool

The USGS Scenario Evaluator for Electrical Resistivity (SEER) is a quick and simple Excel-based decision support tool practitioners can use to assess the likely outcome of using two-dimensional (2D) electrical resistivity imaging for site characterization and remediation monitoring.

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Water Resources Mission Area
Field Photo Friday Winner for May 2021

Field Photo Friday Winner for May 2021

Global Navigation Satellite System (GNSS) Surveying at USGS 04273996 W BR AUSABLE R TRIB 1 ABV ST HW 86 NR LK PLACID NY (Credit: Isabella Lucia, USGS...

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