Comprehensive dataset containing 8 verified Map store businesses in Massachusetts, United States with complete contact information, ratings, reviews, and location data.

This data set contains the sea floor topographic contours, sun-illuminated topographic imagery, and backscatter intensity generated from a multibeam sonar survey of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts, an area of approximately 1100 square nautical miles. The Stellwagen Bank NMS Mapping Project is designed to provide detailed maps of the Stellwagen Bank region's environments and habitats and the first complete multibeam topographic and sea floor characterization maps of a significant region of the shallow EEZ. Data were collected on four cruises over a two year period from the fall of 1994 to the fall of 1996. The surveys were conducted aboard the Candian Hydrographic Service vessel Frederick G. Creed, a SWATH (Small Waterplane Twin Hull) ship that surveys at speeds of 16 knots. The multibeam data were collected utilizing a Simrad Subsea EM 1000 Multibeam Echo Sounder (95 kHz) that is permanently installed in the hull of the Creed.

The Digital Surficial Geologic-GIS Map of Minuteman National Historical Site and Vicinity, Massachusetts is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) a 10.1 file geodatabase (mima_surficial_geology.gdb), a 2.) Open Geospatial Consortium (OGC) geopackage, and 3.) 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. The file geodatabase format is supported with a 1.) ArcGIS Pro map file (.mapx) file and individual Pro layer (.lyrx) files (for each GIS data layer), as well as with a 2.) 10.1 ArcMap (.mxd) map document (mima_surficial_geology.mxd) and individual 10.1 layer (.lyr) files (for each GIS data layer). The OGC geopackage is supported with a QGIS project (.qgz) file. Upon request, the GIS data is also available in ESRI 10.1 shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) this file (mima_geology.gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (mima_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (mima_surficial_geology_metadata_faq.pdf). Please read the mima_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. Google Earth software is available for free at: http://www.google.com/earth/index.html. QGIS software is available for free at: https://www.qgis.org/en/site/. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri,htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (mima_surficial_geology_metadata.txt or mima_surficial_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:50,000 and United States National Map Accuracy Standards features are within (horizontally) 25.4 meters or 83.3 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in Google Earth, ArcGIS, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

Debris flows, debris avalanches, mud flows and lahars are fast-moving landslides that occur in a wide variety of environments throughout the world. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and can strike with little warning. The purpose of this map is to show where debris flows have occurred in the conterminous United States and where these slope movements might be expected in the future.

The U.S. Geological Survey has conducted geologic mapping to characterize the sea floor offshore of Massachusetts. The mapping was carried out using a Simrad Subsea EM 1000 Multibeam Echo Sounder on the Frederick G. Creed on four cruises conducted between 1994 and 1998. The mapping was conducted in cooperation with the National Oceanic and Atmospheric Administration (NOAA) and with support from the Canadian Hydrographic Service and the University of New Brunswick. The long-term goal of this mapping effort is to produce high-resolution geologic maps and a Geographic Information System (GIS) project that presents images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from these surveys that will serve the needs of research, management and the public.

The U.S. Geological Survey has conducted geologic mapping to characterize the sea floor offshore of Massachusetts. The mapping was carried out using a Simrad Subsea EM 1000 Multibeam Echo Sounder on the Frederick G. Creed on four cruises conducted between 1994 and 1998. The mapping was conducted in cooperation with the National Oceanic and Atmospheric Administration (NOAA) and with support from the Canadian Hydrographic Service and the University of New Brunswick. The long-term goal of this mapping effort is to produce high-resolution geologic maps and a Geographic Information System (GIS) project that presents images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from these surveys that will serve the needs of research, management and the public.

The U.S. Geological Survey and the University of Massachusetts at Amherst (UMass Amherst), in cooperation with the Massachusetts Department of Environmental Protection (MassDEP), began a series of studies in 2019 to develop a web-based statewide hydraulic modeling tool to provide preliminary culvert designs to support stream crossing replacement projects in Massachusetts. This Web Map Service (WMS) has been developed to query data from the hydraulic models at select stream crossing locations using the StreamStats web application for Massachusetts. The WMS contains stream crossing point locations with hydrology and hydraulic data tables and associated watershed polygons. These stream crossing locations were derived from the North Atlantic Aquatic Connectivity Collaborative data center (NAACC Data Center). Preliminary culvert designs for three-sided box, conspan arch, and a pipe culvert have been modeled using the U.S. Army Corps of Engineer’s Hydrologic Engineering Center’s River Analysis System (HEC-RAS) software with cross-sectional and channel geometry data derived from high-resolution light detection and ranging (lidar) Digital Elevation Models (DEM). The WMS layer provides the ability to generate reports in the StreamStats web application for Massachusetts at the stream crossing locations for site _location information, preliminary culvert designs, flood flows, bankfull channel geometry, aquatic habitat and stream connectivity restoration potential, basin characteristics, and other select information.

The U.S. Geological Survey has conducted geologic mapping to characterize the sea floor offshore of Massachusetts. The mapping was carried out using a Simrad Subsea EM 1000 Multibeam Echo Sounder on the Frederick G. Creed on four cruises conducted between 1994 and 1998. The mapping was conducted in cooperation with the National Oceanic and Atmospheric Administration (NOAA) and with support from the Canadian Hydrographic Service and the University of New Brunswick.

The long-term goal of this mapping effort is to produce high-resolution geologic maps and a Geographic Information System (GIS) project that presents images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from these surveys that will serve the needs of research, management and the public.

This field activity is part of the effort to map geologic substrates of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts. The overall goal is to develop high-resolution (1:25,000) interpretive maps, based on multibeam sonar data and seabed sampling, showing surficial geology and seabed sediment dynamics. This cruise was conducted in collaboration with the Stellwagen Bank National Marine Sanctuary, and the data collected will aid research on the ecology of fish and invertebrate species that inhabit the region. The Sanctuary's research vessel, R/V Auk, visited 75 locations on Stellwagen Bank at which a customized Van Veen grab sampler (SEABOSS) equipped with a video camera and a CTD was deployed in drift mode to collect sediment for grain-size analysis, video imagery of the seabed, and temperature, conductivity, and depth measurements of the water column. Additional information regarding this field activity is available from https://cmgds.marine.usgs.gov/fan_info.php?fa=2015-062-FA.

The Unpublished Digital Bedrock Geologic Map of Minuteman National Historical Site and Vicinity, Massachusetts is composed of GIS data layers and GIS tables in a 10.0 file geodatabase (mima_geology.gdb), a 10.0 ArcMap (.MXD) map document (mima_geology.mxd), and individual 10.0 layer (.LYR) files for each GIS data layer, an ancillary map information (.PDF) document (mima_geology.pdf) which contains source map unit descriptions, as well as other source map text, figures and tables, metadata in FGDC text (.TXT) and FAQ (.HTML) formats, and a GIS readme file (mima_gis_readme.pdf). Please read the mima_gis_readme.pdf for information pertaining to the proper extraction of the file geodatabase and other map files. To request GIS data in ESRI 10.0 shapefile format contact Stephanie O’Meara (stephanie_o’meara@colostate.edu; see contact information below). The data is also available as a 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. Google Earth software is available for free at: http://www.google.com/earth/index.html. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: Boston College and U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (mima_metadata_faq.html; available at http://nrdata.nps.gov/geology/gri_data/gis/mima/mima_metadata_faq.html). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 25.4 meters or 83.3 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in Google Earth, ArcGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.1. (available at: http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.cfm). The GIS data projection is NAD83, UTM Zone 19N, however, for the KML/KMZ format the data is projected upon export to WGS84 Geographic, the native coordinate system used by Google Earth. The data is within the area of interest of Minuteman National Historical Site.

A regression model that estimates monthly temperature and precipitation as a function of latitude, longitude, and elevation for the New England area was used to estimate annual growing degree days and precipitation for the state of Massachusetts. For details of the regression model please see the published paper (Ollinger, S.V., Aber, J.D., Federer, C.A., Lovett, G.M., Ellis, J.M., 1995. Modeling Physical and Chemical Climate of the Northeastern United States for a Geographic Information System. US Dept of Agriculture, Forest Service, Radnor, PA, USA).

Accurate data and maps of sea-floor geology are important first steps toward protecting habitat, delineating marine resources, and assessing environmental changes due to natural or human effects. Initiated in 2003, the primary objective of the Geologic Mapping of the Massachusetts Sea Floor program is to develop regional geologic framework information for the management of coastal and marine resources. The program is focused on the inshore waters (primarily 5-30 meters deep, although the region surveyed in this field activity includes waters up to 90 meters deep) of Massachusetts. This dataset, collected aboard the Ocean Survey Vessel (OSV) Bold as part of the Geologic Mapping of the Massachusetts Sea Floor Program, is from U.S. Geological Survey (USGS) sampling survey 2012-035-FA (August 21-27, 2012) by the USGS Woods Hole Coastal and Marine Science Center and the Massachusetts Office of Coastal Zone Management with partners from the Massachusetts Bays Program, the Massachusetts Department of Environmental Protection, the Massachusetts Division of Marine Fisheries, and the U.S. Environmental Protection Agency. During the survey, surficial sediment samples and bottom still and video imagery were collected in Ipswich Bay and Massachusetts Bay, Massachusetts.

This dataset consists of long-term (100+ years) linear regression shoreline change rates for the Nantucket region of Massachusetts. Rates of long-term shoreline change were computed within a GIS using the Digital Shoreline Analysis System (DSAS) version 5.0, an ArcGIS extension developed by the U.S. Geological Survey. The baseline is used as a reference line for the transects cast by the DSAS software. The transects intersect each shoreline at the measurement points, which are then used to calculate a linear regression rate for the Massachusetts Office of Coastal Zone Management Shoreline Change Project. Long-term linear regression statistics were calculated with all of the historical shorelines compiled for the Massachusetts Office of Coastal Zone Management Shoreline Change Project. Due to continued coastal population growth and increased threats of erosion, current data on trends and rates of shoreline movement are required to inform shoreline and floodplain management. The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast. In the Massachusetts Shoreline Change Mapping and Analysis Project 2013 Update, two oceanfront shorelines for Massachusetts (approximately 1,800 km) were (1) delineated using 2008/09 color aerial orthoimagery, and (2) extracted from topographic LIDAR datasets (2007) obtained from NOAA's Ocean Service, Coastal Services Center. The most recent 2018 data release includes rates that incorporate two new mean high water (MHW) shorelines for the Massachusetts coast extracted from lidar data collected between 2010 and 2014. The new shorelines were integrated with existing Massachusetts Office of Coastal Zone Management and USGS historical shoreline data in order to compute long- and short-term rates using the latest version of the Digital Shoreline Analysis System (DSAS)

This data set contains the nearshore boundary line, in ESRI shape file format, for the Ocean Management Planning Area pursuant to "An Act Relative to Oceans" for the Commonwealth of Massachusetts. The Nearshore Ocean Management Planning Area Boundary (NOMPAB) line defines the landward limit of the Ocean Management Planning Area and represents the merger of a line projected 0.3 nautical miles (nm) from an approximate mean high water (MHW) shoreline data set and closing lines digitized manually to ensure that most developed coastal embayments, ports, harbors, etc. are located landward of the nearshore boundary. GIS files for this boundary are available for download. Since GIS projection and topology functions can alter or generalize coordinates, however, calculated coordinate values (also available for download) and not GIS files are the official record for the exact NOMPAB.

The Digital Bedrock Geologic-GIS Map of Saugus Iron Works National Historic Site, Massachusetts is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) an ESRI file geodatabase (sair_bedrock_geology.gdb), a 2.) Open Geospatial Consortium (OGC) geopackage, and 3.) 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. The file geodatabase format is supported with a 1.) ArcGIS Pro 3.X map file (.mapx) file (sair_bedrock_geology.mapx) and individual Pro 3.X layer (.lyrx) files (for each GIS data layer). The OGC geopackage is supported with a QGIS project (.qgz) file. Upon request, the GIS data is also available in ESRI shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) a readme file (sair_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (sair_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (sair_bedrock_geology_metadata_faq.pdf). Please read the sair_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. Google Earth software is available for free at: https://www.google.com/earth/versions/. QGIS software is available for free at: https://www.qgis.org/en/site/. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri.htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: Massachusetts Geological Survey and U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (sair_bedrock_geology_metadata.txt or sair_bedrock_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual _location as presented by this dataset. Users of this data should thus not assume the _location of features is exactly where they are portrayed in Google Earth, ArcGIS Pro, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

The Digital Geologic-GIS Map of Cape Cod National Seashore and Vicinity, Massachusetts is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) an ESRI file geodatabase (caco_geology.gdb), a 2.) Open Geospatial Consortium (OGC) geopackage, and 3.) 2.2 KMZ/KML file for use in Google Earth, however, this format version of the map is limited in data layers presented and in access to GRI ancillary table information. The file geodatabase format is supported with a 1.) ArcGIS Pro 3.X map file (.mapx) file (caco_geology.mapx) and individual Pro 3.X layer (.lyrx) files (for each GIS data layer). The OGC geopackage is supported with a QGIS project (.qgz) file. Upon request, the GIS data is also available in ESRI shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) a readme file (caco_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (caco_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (caco_geology_metadata_faq.pdf). Please read the caco_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. Google Earth software is available for free at: https://www.google.com/earth/versions/. QGIS software is available for free at: https://www.qgis.org/en/site/. Users are encouraged to only use the Google Earth data for basic visualization, and to use the GIS data for any type of data analysis or investigation. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri.htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: U.S. Geological Survey. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (caco_geology_metadata.txt or caco_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in Google Earth, ArcGIS Pro, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

Open spaces of conservation and recreation interest in Boston, Massachusetts, USA, regardless of ownership.

Accurate data and maps of sea-floor geology are important first steps toward protecting habitat, delineating marine resources, and assessing environmental changes due to natural or human effects. Initiated in 2003, the primary objective of the Geologic Mapping of the Massachusetts Sea Floor program is to develop regional geologic framework information for the management of coastal and marine resources. The program is focused on the inshore waters (primarily 5-30 meters deep, although the region surveyed in this field activity includes waters up to 90 meters deep) of Massachusetts. This dataset, collected aboard the Ocean Survey Vessel (OSV) Bold as part of the Geologic Mapping of the Massachusetts Sea Floor Program, is from U.S. Geological Survey (USGS) sampling survey 2012-035-FA (August 21-27, 2012) by the USGS Woods Hole Coastal and Marine Science Center and the Massachusetts Office of Coastal Zone Management with partners from the Massachusetts Bays Program, the Massachusetts Department of Environmental Protection, the Massachusetts Division of Marine Fisheries, and the U.S. Environmental Protection Agency. During the survey, surficial sediment samples and bottom still and video imagery were collected in Ipswich Bay and Massachusetts Bay, Massachusetts.

The New Bedford, MA Meter-Scale Urban Land Cover (MULC) data were generated from United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1 m spatial resolution. Imagery was collected in August of 2010. Seven land cover classes were mapped: water, impervious surfaces, soil and barren land, trees and forest, grass and herbaceous non-woody vegetation, woody wetlands and emergent wetlands. An accuracy assessment of 500 completely random and 45 stratified random points yielded an overall user's accuracy (MAX) of 92.3% and an overall fuzzy user's accuracy (RIGHT) of 95.1%. The area mapped is defined by the US Census Bureau's 2010 Urban Statistical Area for New Bedford, MA plus a 1 km buffer. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

In June 2022, the U.S. Geological Survey, in collaboration with the Massachusetts Office of Coastal Zone Management, collected high-resolution geophysical data, in Nantucket Sound to understand the regional geology in the vicinity of Horseshoe Shoal. This effort is part of a long-term collaboration between the USGS and the Commonwealth of Massachusetts to map the State’s waters, support research on the Quaternary evolution of coastal Massachusetts, resolve the influence of sea-level change and sediment supply on coastal evolution, and strengthen efforts to understand the type, distribution, and quality of subtidal marine habitats. This collaboration produces high-resolution geologic data that serve the needs of research, management, and the public. Data collected as part of this mapping cooperative continue to be released in a series of USGS Open-File Reports and Data Releases https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor.