Heat is used as a tracer for a variety of physical hydrogeological process. Several types of instruments are used to measure the temperature of surface water and saturated sediments. In the Quashnet River we have been using methods that include: infrared, individual logging thermistors, and fiber-optic distributed temperature sensing. The latter type of data (FO_DTS) are described and presented here.

Fiber-optic distributed temperature sensing (FO-DTS) cables were deployed along the sediment/water interface to map high spatial resolution temperature variations along the streambed. These variations are used to detect zones of groundwater discharge. Data are to be used in conjunction with electromagnetic imaging (EMI) and ground penetrating radar (GPR) data. The combined dataset represents point in time mapping of preferential groundwater discharge points (FO-DTS), and the bed structure that controls where these points are located (GPR, EMI).

Fiber-optic distributed temperature sensing (FO-DTS) cables were deployed along the sediment/water interface to map high spatial resolution temperature variations along the streambed. These variations are used to detect zones of groundwater discharge. Data are to be used in conjunction with electromagnetic imaging (EMI) and ground penetrating radar (GPR) data. The combined dataset represents point in time mapping of preferential groundwater discharge points (FO-DTS), and the bed structure that controls where these points are located (GPR, EMI).

The temperature and surface geophysical data contained in this release have primarily been collected to support groundwater/surface water methods development, and to characterize the hydrogeological controls on native brook trout habitat. All data have been collected since 2010 along the Quashnet River corridor located on Cape Cod, MA, USA. Cape Cod is a peninsula in southeastern coastal Massachusetts, USA, composed primarily of highly permeable unconsolidated glacial moraine and outwash deposits. The largest of the Cape Cod sole-source aquifers occupies a western (landward) section of the peninsula, and is incised by several linear valleys that drain groundwater south to the Atlantic Ocean via baseflow-dominated streams. Strong groundwater discharge to the Quashnet River supports a relatively stable flow regime, as monitored by USGS gage 011058837, located at the downstream end of typical field research focus areas. The lower Quashnet River emerges from a narrow sand and gravel valley to a broader area with well-defined lateral floodplains. Historical cranberry farming practices, abandoned in the 1950s, have modified the stream corridor as described by: Barlow, P. M. and Hess, K. M.: Simulated Hydrologic Responses of the Quashnet River Stream-Auquifer System to Proposed Ground-Water Withdrawals, Cape Cod, Massachusetts, U.S. Geol. Surv. Rep. 93-4064, 51, 1993. The Massachusetts Division of Fisheries and Wildlife has been monitoring brook trout populations in the Quashnet River since 1988 and movement since 2007. Groundwater influence on stream temperature is pronounced, particularly over the 2-km reach above the USGS gage, below which stream stage is tidally affected.

Surface geophysical tools remotely sense hydrogeological properties that can control subsurface flow and water quality. There are numerous geophysical tools, for the Quashnet River work we have principally used ground penetrating radar (GPR) and electromagnetic imaging (EMI). The instruments are either hand carried or floated down the stream channel and other cross-sections of the river corridor. Data from various field deployments of GPR and EMI are described and presented here.

Surface geophysical tools remotely sense hydrogeological properties that can control subsurface flow and water quality. There are numerous geophysical tools, for the Quashnet River work we have principally used ground penetrating radar (GPR) and electromagnetic imaging (EMI). The instruments are either hand carried or floated down the stream channel and other cross-sections of the river corridor. Data from various field deployments of GPR and EMI are described and presented here.

This child page contains fiber-optic distributed temperature sensing data collected from March 13-March 16, 2018 at the North Chevalier Field Disposal Area (Site 11) at Naval Air Station Pensacola in Pensacola Bay in Florida. A fiber-optic cable was run on the bottom of the bay parallel to the shoreline along an approximate 370-meter reach. The cable was installed near the shoreline just far enough offshore that most of it remained submerged at low tide. At the end of the reach, the cable was doubled back and installed parallel to, and approximately one meter offshore, of the first run. At the end of the second run, the cable was run ashore and connected to an Oryx Distributed Temperature Sensing (DTS) system. Near the DTS, several coils of the fiber optic cable were submerged in an ice slurry for the duration of the survey as a quality control measure. Temperature was measured every 15 minutes at one-meter intervals along the length of the cable. The temperature data, which are reported by the instrument as linear fiber distance, were georeferenced using a handheld Global Positioning System (GPS) for the purpose of relating known points in space to the distance along the fiber-optic cable. Additional details of the temperature survey can be found using the link to the companion U.S. Geological Survey (USGS) Scientific Investigations Report.

The Massachusetts Division of Fisheries and Wildlife has been studying brook trout populations in Cape Cod groundwater-fed river systems for decades. Recently, a notable reduction in trout population in the Santuit River sparked the concern of several groups, including the Wampanoag Tribe. Brook trout population dynamics may be tied to water quality and temperature changes, which are both impacted by spatially preferential groundwater discharge to the river. The streambed interface temperature and near-surface geophysical data compiled in this data release were collected in summer 2018 as part of a larger effort to characterize the spatial distribution of groundwater discharge zones, and exchanges with surface water, along Cape Cod stream systems. Fiber-optic distributed temperature sensing (FO-DTS) cables were deployed along the sediment/water interface to map high spatial resolution temperature variations along the streambed that are used to locate discharges. Geophysical data include towed ground penetrating radar (GPR) data to image near surface streambed structure, and hand-carried electromagnetic imaging (EMI) data to indicate changes in streambed water quality and/or near surface sediments. Therefore, this combined dataset represents point-in-time mapping of preferential groundwater discharge points (FO-DTS), and the bed structure that controls where these points are located (GPR, EMI).

The Massachusetts Division of Fisheries and Wildlife has been studying brook trout populations in Cape Cod groundwater-fed river systems for decades. Recently, a notable reduction in trout population in the Santuit River sparked the concern of several groups, including the Wampanoag Tribe. Brook trout population dynamics may be tied to water quality and temperature changes, which are both impacted by spatially preferential groundwater discharge to the river. The streambed interface temperature and near-surface geophysical data compiled in this data release were collected in summer 2018 as part of a larger effort to characterize the spatial distribution of groundwater discharge zones, and exchanges with surface water, along Cape Cod stream systems. Fiber-optic distributed temperature sensing (FO-DTS) cables were deployed along the sediment/water interface to map high spatial resolution temperature variations along the streambed that are used to locate discharges. Geophysical data include towed ground penetrating radar (GPR) data to image near surface streambed structure, and hand-carried electromagnetic imaging (EMI) data to indicate changes in streambed water quality and/or near surface sediments. Therefore, this combined dataset represents point-in-time mapping of preferential groundwater discharge points (FO-DTS), and the bed structure that controls where these points are located (GPR, EMI).

Heat is used as a tracer for a variety of physical hydrogeological process. Several types of instruments are used to measure the temperature of surface water and saturated sediments. In the Quashnet River we have been using methods that include: infrared, fiber-optic distributed temperature sensing, and individual logging thermistors. The latter type of data (thermistor) are described and presented here.