Laura Brothers, PhD
My research focuses on coastal and shelf evolution, and includes regional geologic framework, shallow geohazards and permafrost studies.
Biography
Dr. Laura Brothers is a marine geologist at the USGS Woods Hole Coastal and Marine Science Center. She studies how the seafloor, and the earth beneath the seafloor change with time and major events. From the shores of the Arctic, Gulf of Maine, Mid-Atlantic and to the deep sea Laura has worked in teams that have geologically mapped tens of thousands of kilometers of the seabed using geophysical and advanced imaging data. Laura led the DOI Hurricane Sandy supplemental project focused on defining the geologic framework offshore of the Delmarva Peninsula. She leads the USGS-partnership with the State of Massachusetts to geologically map the State’s inner continental shelf.
Publications
Science and Products
Massachusetts Integrated Coastal Studies (MICS)
Coastal erosion, intense storm events and sea-level rise pose threats to coastal communities and infrastructure. Managers and scientists often lack the high-resolution data needed to improve estimates of sediment abundance and movement, shoreline change, and seabed characteristics that influence coastal vulnerability. To address these and other needs the U.S. Geological Survey, in partnership...
Geologic Mapping of the Massachusetts Seafloor
The U.S. Geological Survey, in cooperation with the Massachusetts Office of Coastal Zone Management (CZM) is conducting geologic mapping of the sea floor to characterize the surface and shallow subsurface geologic framework within the Massachusetts coastal zone. The long-term goal of this mapping effort is to produce high-resolution geologic maps and a Geographic Information System (GIS) that...
Hurricane Sandy Response- Linking the Delmarva Peninsula's Geologic Framework to Coastal Vulnerability
The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy. In order to better constrain controls on coastal vulnerability and evolution, the region’s sediment sources, transport pathways and sediment sinks must be identified. This project defines the geologic framework of the Delmarva coastal system through...
High-resolution geophysical data collected in the Belfast Bay, Maine pockmark field in 2006, 2008, and 2009 by the U.S. Geological Survey
The U.S. Geological Survey, Woods Hole Coastal and Marine Science Center in cooperation with the University of Maine mapped approximately 50 square kilometers of the seafloor within Belfast Bay, Maine. Three geophysical surveys conducted in 2006, 2008 and 2009 collected swath bathymetric (2006 and 2008) and chirp seismic reflection profile data (2006 and 2009).
Sea-Floor Sediment and Imagery Data Collected in Nantucket Sound, Massachusetts, 2016 and 2017
Two marine geological surveys were conducted in Nantucket Sound, Massachusetts, in May 2016 and May 2017 by the U.S. Geological Survey as part of an agreement with the Massachusetts Office of Coastal Zone Management to map the geology of the sea floor offshore of Massachusetts. Samples of surficial sediment and photographs of the sea floor were collected at 76 sampling sites within the survey...
High-resolution geophysical data collected along the Delmarva Peninsula 2014, U.S. Geological Survey Field Activity 2014-002-FA
Data collected during the 2014 cruise include swath bathymetry, sidescan sonar, chirp and boomer seismic-reflection profiles, acoustic Doppler current profiler, and sample and bottom photograph data. Processed data in raster and vector format are released here for the swath bathymetry, sidescan sonar, and seismic-reflection profiles.
Minimal offshore extent of ice-bearing (subsea) permafrost on the U.S. Beaufort Sea margin
Using a compilation of more than 50,000 stacking velocities from ~100,000 line-km of industry-collected multichannel seismic reflection data acquired over 57,000 square kilometers of the U.S. Beaufort Sea continental shelf, we derive the average (bulk) velocity in the upper 750 milliseconds of two-way travel time (TWTT).
Geospatial Data Layers of Shallow Geology, Sea-Floor Texture, and Physiographic Zones from the Inner Continental Shelf of Martha’s Vineyard from Aquinnah to Wasque Point, and Nantucket from Eel Point to Great Point
Geologic, sediment texture, and physiographic zone maps characterize the sea floor south and west of Martha's Vineyard and north of Nantucket, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples.
Sediment Texture and Geomorphology of the Sea Floor from Fenwick Island, Maryland to Fisherman's Island, Virginia
These data are a qualitatively derived interpretive polygon shapefile defining surficial sediment type and distribution, and geomorphology, for nearly 1,400 square kilometers of sea floor on the inner-continental shelf from Fenwick Island, Maryland to Fisherman’s Island, Virginia, USA.
High-resolution geophysical data collected along the Delmarva Peninsula in 2015, U.S. Geological Survey Field Activity 2015-001-FA
The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy in the fall of 2012. The U.S. Geological Survey conducted cruises during the summers of 2014 and 2015 to map the inner continental shelf of the Delmarva Peninsula using geophysical and sampling techniques to define the geologic framework
Molluscan aminostratigraphy of the US Mid-Atlantic Quaternary coastal system: Implications for onshore-offshore correlation, paleochannel and barrier island evolution, and local late Quaternary sea-level history
The Quaternary record of the US Mid-Atlantic coastal system includes onshore emergent late Pleistocene shoreline deposits, offshore inner shelf and barrier island units, and paleovalleys formed during multiple glacial stage sea-level lowstands. The geochronology of this coastal system is based on uranium series, radiocarbon, amino acid...
Wehmiller, John; Brothers, Laura L.; Ramsey, Kelvin; Foster, David S.; Mattheus, C.R.; Hein, Christopher; Shawler, Justin L. Seismic stratigraphic framework of the continental shelf offshore Delmarva, U.S.A.: Implications for Mid-Atlantic Bight evolution since the Pliocene
Understanding how past coastal systems have evolved is critical to predicting future coastal change. Using over 12,000 trackline kilometers of recently collected, co-located multi-channel boomer, sparker and chirp seismic reflection profile data integrated with previously collected borehole and vibracore data, we define the upper (< 115 m...
Brothers, Laura L.; Foster, David S.; Pendleton, Elizabeth A.; Baldwin, Wayne E. Optimizing an inner-continental shelf geologic framework investigation through data repurposing and machine learning
The U.S. Geological Survey (USGS) and the National Oceanic Atmospheric Administration (NOAA) have collected approximately 5,400 km2 of geophysical and hydrographic data on the Atlantic continental shelf between Delaware and Virginia over the past decade and a half. Although originally acquired for different objectives, the comprehensive coverage...
Pendleton, Elizabeth A.; Brothers, Laura L.; Sweeney, Ed
Shallow geology, sea-floor texture, and physiographic zones of the inner continental shelf from Aquinnah to Wasque Point, Martha’s Vineyard, and Eel Point to Great Point, Nantucket, Massachusetts
A series of interpretive maps that describe the shallow geology, distribution, and texture of sea-floor sediments, and physiographic zones of the sea floor along the south and west shores of Martha’s Vineyard and the north shore of Nantucket, Massachusetts, were produced by using high-resolution geophysical data (interferometric and multibeam...
Pendleton, Elizabeth A.; Baldwin, Wayne E.; Ackerman, Seth D.; Foster, David S.; Andrews, Brian D.; Schwab, William C.; Brothers, Laura L. Sand ridge morphology and bedform migration patterns derived from bathymetry and backscatter on the inner-continental shelf offshore of Assateague Island, USA
The U.S. Geological Survey and the National Oceanographic and Atmospheric Administration conducted geophysical and hydrographic surveys, respectively, along the inner-continental shelf of Fenwick and Assateague Islands, Maryland and Virginia over the last 40 years. High resolution bathymetry and backscatter data derived from surveys over the...
Pendleton, Elizabeth A.; Brothers, Laura L.; Thieler, E. Robert; Sweeney, Edward Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing
Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water...
Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L. Observations of pockmark flow structure in Belfast Bay, Maine, Part 2: evidence for cavity flow
Pockmark flow circulation patterns were investigated through current measurements along the rim and center of two pockmarks in Belfast Bay, Maine. Observed time-varying current profiles have a complex vertical and directional structure that rotates significantly with depth and is strongly dependent on the phase of the tide. Observations of the...
Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L. Observations of pockmark flow structure in Belfast Bay, Maine, Part 3: implications for sediment transport
Current observations and sediment characteristics acquired within and along the rim of two pockmarks in Belfast Bay, Maine, were used to characterize periods of sediment transport and to investigate conditions favorable to the settling of suspended sediment. Hourly averaged Shields parameters determined from horizontal current velocity profiles...
Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L. High-resolution geophysical data collected along the Delmarva Peninsula 2014, U.S. Geological Survey Field Activity 2014-002-FA
The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy. A U.S. Geological Survey cruise was conducted in the summer of 2014 to map the inner continental shelf of the Delmarva Peninsula using geophysical and sampling techniques to define the geologic framework...
Pendleton, Elizabeth; Ackerman, Seth D.; Baldwin, Wayne E.; Danforth, William W.; Foster, David S.; Thieler, E. Robert; Brothers, Laura Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 1. Minimum seaward extent defined from multichannel seismic reflection data
Subsea ice-bearing permafrost (IBPF) and associated gas hydrate in the Arctic have been subject to a warming climate and saline intrusion since the last transgression at the end of the Pleistocene. The consequent degradation of IBPF is potentially associated with significant degassing of dissociating gas hydrate deposits. Previous studies...
Brothers, Laura L.; Herman, Bruce M.; Hart, Patrick E.; Ruppel, Carolyn D. Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints
Borehole logging data from legacy wells directly constrain the contemporary distribution of subsea permafrost in the sedimentary section at discrete locations on the U.S. Beaufort Margin and complement recent regional analyses of exploration seismic data to delineate the permafrost's offshore extent. Most usable borehole data were acquired on a ∼...
Ruppel, Carolyn D.; Herman, Bruce M.; Brothers, Laura L.; Hart, Patrick E. Pockmarks in Passamaquoddy Bay, New Brunswick, Canada
Pockmarks are seafloor depressions associated with fluid escape (Judd & Hovland 2007). They proliferate in the muddy seafloors of coastal Gulf of Maine and Bay of Fundy, where they are associated with shallow natural gas likely of biogenic origin (Ussler et al. 2003; Rogers et al. 2006; Wildish et al. 2008). In North America, shallow-water...
Brothers, Laura L.; Legere, Christine; Hughes Clark, J.E.; Kelley, J.T.; Barnhardt, Walter; Andrews, Brian; Belknap, D.F.
USGS and NOAA merge collections to create new high-resolution, broad-scale geologic maps of the seafloor
USGS and NOAA collaborate to create high-resolution maps on the Atlantic continental shelf between Delaware and Virginia.
Marine geologic maps of the inner continental shelf of Massachusetts, where science meets art
Marine geologic maps of the inner continental shelf of Massachusetts, where science, scientists, and art come together to create visually appealing interpretive maps that are critical to aid statewide efforts to inventory and manage coastal and marine resources.
Comprehensive Geologic Mapping of the Inner Continental Shelf off the Delmarva Peninsula
The USGS has collected new geophysical data, seafloor grab samples, and video footage from the inner continental shelf off the Delmarva Peninsula as well as acquired and optimized NOAA and BOEM data.
Subsea Permafrost and Associated Methane Hydrate on the U.S. Arctic Ocean Margin
A new publication by USGS and BOEM provides the most complete information to date about the seaward extent of remaining subsea permafrost and possible relict gas hydrate beneath the U.S. Beaufort Sea margin at the edge of the Arctic Ocean.