Physiographic Zones of the Sea Floor of Buzzards Bay, Massachusetts (BuzzardsBay_Pzones, polygon shapefile, Geographic WGS 84)

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Frequently anticipated questions:


What does this data set describe?

Title:
Physiographic Zones of the Sea Floor of Buzzards Bay, Massachusetts (BuzzardsBay_Pzones, polygon shapefile, Geographic WGS 84)
Abstract:
Geologic, sediment texture, and physiographic zone maps characterize the sea floor of Buzzards Bay, Massachusetts. These maps were derived from interpretations of seismic-reflection profiles, high-resolution bathymetry, acoustic-backscatter intensity, bottom photographs, and surficial sediment samples. The interpretation of the seismic stratigraphy and mapping of glacial and Holocene marine units provided a foundation on which the surficial maps were created. This mapping is a result of a collaborative effort between the U.S. Geological Survey and the Massachusetts Office of Coastal Zone Management to characterize the surface and subsurface geologic framework offshore of Massachusetts.
  1. How might this data set be cited?
    Foster, David S., 2014, Physiographic Zones of the Sea Floor of Buzzards Bay, Massachusetts (BuzzardsBay_Pzones, polygon shapefile, Geographic WGS 84): Open-File Report 2014-1220, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Foster, David S., Baldwin, Wayne E., Barnhardt, Walter A., Schwab, William C., Ackerman, Seth D., Andrews, Brian D., and Pendleton, Elizabeth A., 2014, Shallow Geology, Sea-Floor Texture, Physiographic Zones of Buzzards Bay, Massachusetts: Open-File Report 2014-1220, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.125628
    East_Bounding_Coordinate: -70.602505
    North_Bounding_Coordinate: 41.767340
    South_Bounding_Coordinate: 41.369362
  3. What does it look like?
    http://pubs.usgs.gov/of/2014/1220/GIS_catalog/PhysiographicZones/BuzzardsBay_Pzones_browse.png (PNG)
    Image of the physiographic zone shapefile for Buzzards Bay
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 01-Jan-2004
    Ending_Date: 31-Aug-2011
    Currentness_Reference:
    ground condition of the source data that this interpretation is based on
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • G-polygon (771)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    BuzzardsBay_Pzones
    Physiographic zones shapefile for Buzzards Bay (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    Pzone_name
    Based on geologic maps produced for the Western Gulf of Maine (Kelley and others, 1989), the sea-floor within the study area can be divided into geologic environments, or physiographic zones, which are delineated from sea-floor morphology and the dominant texture of surficial material. (Source: U.S. Geological Survey)
    ValueDefinition
    Rocky ZoneRocky Zones (RZ) are rugged areas of high bathymetric relief, rising above the Nearshore Basins, ranging from rocky ledges to relatively flat, gravel-covered plains to boulder fields. Water depths range from 3 to 45 m. Although ledge and coarse-grained sediment are found within all physiographic zones defined here, they dominate the sea floor in Rocky Zones.
    Nearshore BasinNearshore Basins (NB) are areas of shallow, low-relief sea floor adjacent to the mainland and separated from offshore areas by islands and shoals. Water depths range from 0 to 47 m. Along its landward margin, the basin sediment merges with the intertidal zone, often a Nearshore Ramp, in a gradational contact.
    Nearshore RampNearshore Ramps (NR) are areas of gently sloping sea floor with generally shore-parallel bathymetric contours. Water depths range from 0 to 29 m. This zone is covered primarily with sand-rich sediment, although small rocky ledge exposures, cobbles and boulders crop out on the sea floor in places. Nearshore Ramps are mostly confined to cuspate shorelines between coastal headlands and typically grade into the Nearshore Basin.
    Ebb-Tidal DeltaEbb-tidal Deltas (ETD) are lobate sandy shoals found on the side of inlets that form through the interaction of waves and ebbing tidal currents flowing from Vineyard Sound. Water depths range from 1 to 14 m. The only Ebb-tidal Deltas mapped within Buzzards Bay are on the bay side of tidal passages between the Elizabeth Islands.
    Hard-Bottom PlainsHard-bottom Plains (HBP) tend to have low bathymetric relief, with a coarse sediment texture consisting of primarily sand and gravel.
    Dredged ChannelDredged Channels (DC) are anthropogenic features where the sea floor has been modified to accommodate navigation.
    Dredge SpoilAreas where anthropogenically derived dredged materials (DS) have been dumped on the sea floor. These areas show irregular bathymetry, roughness and acoustic backscatter that often contrast with the surrounding geology.
    Coastal EmbaymentCoastal Embayments (CE) include the coastal ponds described by FitzGerald and others (1987) along the northwest shore of Buzzards Bay and the smaller bays and harbors along the Cape Cod and Elizabeth Islands shores. Some of the shallow coastal water bodies, particularly the drowned river valleys along the northwest shore of Buzzards Bay, fit the description of coastal lagoons where these water bodies are separated from the ocean by a barrier but connected at least intermittently to the ocean with at least one restricted inlet Kjerfve (1994). Fitzgerald and others (1994) would refer to the coastal water bodies along northwestern Buzzards Bay as embayments. In this report, we refer to all partially enclosed shallow coastal water bodies along the Buzzards Bay margin as coastal embayments.
    data_confi
    These zones were defined qualitatively in ArcMap using the same sources used to derive the sediment texture map. The polygons were assigned two levels of confidence, high (1) or low (0), based on the same criteria used in the sediment texture mapping. (Source: U.S. Geological Survey)
    ValueDefinition
    0Areas of low interpretation confidence where only single beam bathymetry and qualitative sediment sample descriptions exist.
    1Areas of high interpretation confidence where swath bathymetry, acoustic backscatter, and seismic reflection data exist. In general these areas also contain quantitative sediment statistics and bottom photographs.
    2Sediment texture regions that were defined based on the highest resolution bathymetry (10m) and backscatter (1m), bottom photos, qualitative descriptions of sediment samples, and seismic interpretations were given the data interpretation confidence value of 2
    3Sediment texture regions that were defined based on low resolution single beam bathymetry and sediment samples descriptions were given the data interpretation confidence value of 3
    4Sediment texture regions that were defined based on low resolution single beam bathymetry were given the lowest (4) data interpretation confidence value of 4
    Area
    Area of feature in kilometers squared. (Source: Esri)
    Range of values
    Minimum:0.000133
    Maximum:335.25699
    Units:square kilometers
    Resolution:0.000001

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • David S. Foster
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    David S. Foster
    U.S. Geological Survey
    Geologist
    U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov

Why was the data set created?

These sea floor physiographic zones were created from geophysical and sample data collected from Buzzards Bay, and are used to characterize the sea floor in the area. Physiographic zone maps are important data layers for marine resource managers charged with protecting fish habitat, delineating marine boundaries, and assessing environmental change due to natural or human impacts.

How was the data set created?

  1. From what previous works were the data drawn?
    Poppe and others, 2007 (source 1 of 9)
    Poppe, L.J., Ackerman, S.D., Foster, D.S., Blackwood, D.S., Butman, B., Moser, M.S., and Stewart, H.F., 2007, Sea-floor character and surface processes in the vicinity of Quicks Hole, Elizabeth Islands, Massachusetts: Open-File Report 2006-1357, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This publication provides the source geophysical (backscatter and bathymetry) and bottom photographs and sediment samples for the Quicks Hole area of Buzzards Bay. Two 29-foot launches deployed from the NOAA Ship Thomas Jefferson were used to acquire bathymetric and backscatter data during 2004. The multibeam bathymetric data were collected with hull-mounted 455-kHz RESON 8125 and 240-kHz RESON 8101 systems. The sidescan sonar data were acquired with a hull-mounted Klein 5250 system operating at 100 kHz. Sediment samples and bottom photos were collected aboard the R/V Rafael with a modified Van Veen grab sampler and SEABOSS, respectively.
    Pendleton and others, 2012 (source 2 of 9)
    Pendleton, E.A., Twichell, D.C., Foster, D.S., Worley, C.R, Irwin, B.J., and Danforth, W.W., 2012, High-resolution geophysical data from the sea floor surrounding the Western Elizabeth Islands, Massachusetts: Open-File Report 2011-1184, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This report provided source geophysical (sidescan, bathymetry, and seismic-reflection profiles) for the area of Buzzards Bay surrounding the western Elizabeth Islands. Surveying was conducted aboard the RV Rafael in September 2010. Interferometric-sonar, sidescan-sonar, and chirp seismic-reflection systems were deployed simultaneously during the cruise. Bathymetric sounding data were collected with an SEA SWATHplus 234-kilohertz (kHz) interferometric sonar system. Sidescan-sonar (acoustic-backscatter) data were acquired with a Klein 3000 dual-frequency (100 and 500 kHz) sidescan-sonar system. High-resolution chirp seismic-reflection profiles were collected using an EdgeTech Geo-Star full spectrum sub-bottom (FSSB) system and SB-424 towfish.
    Turecek and others, 2012 (source 3 of 9)
    Turecek, A.M., Danforth, W.W., Baldwin, W.E., and Barnhardt, W.A., 2012, High-resolution geophysical data collected within Red Brook Harbor, Buzzards Bay, Massachusetts, in 2009: Open-File Report 2010-1091, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This report provided the source geophysical (sidescan, bathymetry, and seismic-reflection profiles), sediment sample and bottom photograph data for Buzzards Bay in the area of Red Brook Harbor. Surveying was conducted aboard the R/V Rafael. Bathymetric data were collected with an SEA SWATHplus 234-kilohertz (kHz) interferometric sonar system. Acoustic backscatter, a measure of the intensity of returns from an insonified area of the sea floor, was recorded by the SEA SWATHplus interferometric sonar system. Seismic reflection profiles were collected with a Knudsen Engineering, Ltd. (KEL) Chirp 3202 dual-frequency (centered at 3.5- and 200-kHz) Chirp system. The USGS Mini SEABed Observation and Sampling System (Mini SEABOSS) was used to collect digital photography and video and sediment samples
    Ackerman and others, 2013 (source 4 of 9)
    Ackerman, S.D., Andrews, B.D., Foster, D.S., Baldwin, W.E., and Schwab, W.C., 2013, High-Resolution Geophysical Data from the Inner Continental Shelf: Buzzards Bay, Massachusetts: Open-File Report 2012-1002, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This report provided the source geophysical (sidescan, bathymetry, and seismic-reflection profiles) for Buzzards Bay. The mapping was conducted during research cruises aboard the NOAA Ship RUDE (2004), the Megan T. Miller (2009 and 2010) and the Scarlett Isabella (2011). The NOAA Ship RUDE acquired bathymetric soundings in 2004 using a RESON SeaBat 8125 455-kHz multibeam-echosounder system. All other surveys used the following systems: bathymetric data were acquired in the Buzzards Bay survey area using a Systems Engineering and Assessment, Ltd. (SEA) SWATHplus-M 234-kilohertz (kHz) interferometric sonar system; acoustic backscatter data were collected with a Klein 3000 dual-frequency sidescan-sonar (132 and 445 kHz); chirp seismic-reflection data were collected in the Buzzards Bay survey area using an EdgeTech Geo-Star FSSB subbottom profiling system and an SB-0512i towfish.
    Pendleton and others, 2014 (source 5 of 9)
    Pendleton, E.A., Andrews, B.D., Danforth, W.W., and Foster, D.S., 2014, High-resolution geophysical data collected aboard the U.S. Geological Survey research vessel Rafael to supplement existing datasets from Buzzards Bay and Vineyard Sound, Massachusetts: Open-File Report 2013-1020, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This report provided the source geophysical (sidescan, bathymetry, and seismic-reflection profiles) for Buzzards Bay in the area of Naushon Island and seismic-reflection profiles in northeast Buzzards Bay. These areas were surveyed with the RV Rafael in 2010 and 2011. In 2010, seismic-reflection data were acquired with a boomer source and GeoEel 8-channel streamer. Interferometric-sonar, sidescan-sonar, and Knudsen seismic-reflection systems were deployed simultaneously during cruise 2011. Bathymetry data were collected with an SEA SWATHplus 234-kilohertz (kHz) interferometric sonar system. Sidescan-sonar (acoustic-backscatter) data were acquired with a Klein 3000 dual-frequency (100 and 500 kHz) sidescan-sonar system. High-resolution chirp seismic data were collected using a dual frequency (3.5 and 200 kHz) Knudsen Engineering Limited (KEL) Chirp 3202 system.
    CZM sample database (source 6 of 9)
    Ford, K.H., Huntley, E.C., Sampson, D.W., and Voss, S., Unpublished Material, Massachusetts Sediment Database.

    Other_Citation_Details:
    This sample database has been compiled and vetted from existing samples and datasets by the Massachusetts Office of Coastal Zone Management. The data are currently unpublished, but may be acquired by contacting the CZM office: 251 Causeway St Boston, MA 02114 (617) 626-1000 czm@state.ma.us
    Type_of_Source_Media: digital vector
    Source_Contribution:
    Sediment sample databases of Ford and Voss (2010) and McMullen and others (2011) were combined then edited and supplemented with NOAA chart sampling data and bottom photos and descriptions by a group of GIS specialists at the Massachusetts Office of Coastal Zone Management (Emily Huntley, personal communication). These data contained sediment laboratory statistics when available, visual descriptions if sediment analysis was not performed or if the site was a bottom photograph, and classification fields of Barnhardt and others (1998), Shepard (1954), and Wentworth (1922) as well as average sediment statistics and phi size, when laboratory analysis was conducted.
    Poppe and others, 2008 (source 7 of 9)
    Poppe, L.J., McMullen, K.Y., Foster, D.S., Blackwood, D.S., Williams, S.J., Ackerman, S.A., Barnum, S.R., and Brennan, R.T., 2008, Sea-floor character and sedimentary processes in the vicinity of Woods Hole, Massachusetts: Open File Report 2008-1004, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This publication provides the source geophysical (backscatter and bathymetry) and bottom photographs and sediment samples for Woods Hole. Two 29-foot launches deployed from the NOAA Ship Whiting were used to acquire bathymetric and backscatter data during 2001. The bathymetric data were collected with a hull-mounted 240-kHz RESON 8101 shallow-water system aboard launch 1005. The sidescan-sonar data were acquired with a hull-mounted Klein T-5000 system operating at 455 kHz aboard launch 1014. Sediment samples and bottom photos were collected aboard the R/V Rafael with a modified Van Veen grab sampler and SEABOSS, respectively, in 2007
    Ackerman and others, 2014 (source 8 of 9)
    Ackerman, S. D, Pappal, A.L., Huntley, E.C., Blackwood, D.S., and Schwab, W.C., 2014, Geological Sampling Data and Benthic Biota Classification: Buzzards Bay and Vineyard Sound, Massachusetts: Open File Report 2014-1220, U.S. Geological Survey, Reston, VA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    This report provided high-resolution digital photographs of the Buzzards Bay sea floor. At each station, the USGS SEABOSS was towed approximately one meter off the bottom at speeds of less than one knot. Because the recorded position is actually the position of the GPS antenna on the survey vessel, not the SEABOSS sampler, the estimated horizontal accuracy of the sample location is ± 30 meters (m). Photographs were obtained using a Konica-Minolta DiMAGE A2 digital still camera, and continuous video was collected from a Kongsberg Simrad OE1365 high-resolution color video camera, usually for 5 to 15 minutes. These data were important in defining rocky zones where sediment samples do not exist.
    Mass GIS 1:25000 state outline (source 9 of 9)
    MassGIS, 199103, MA State Outline (25k coast) (Polygons): EOEA - MassGIS, Boston, MA.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    In order to create the interpretation, first the polygon shapefile of the Massachusetts coast (1:25,000) OUTLINE25K_POLY (http://www.mass.gov/mgis/cs.htm) was reprojected from Massachusetts State Plane NAD83 to WGS84 UTM Zone 19N using ArcMap (version 9.3): ArcToolbox -- Data Management Tools -- Projections and Transformations -- Feature -- Project. The polygon was edited so that it enclosed Buzzards Bay and surrounding coastal embayments.
  2. How were the data generated, processed, and modified?
    Date: 2013 (process 1 of 7)
    The texture and spatial distribution of sea-floor sediment were qualitatively-analyzed in ArcGIS using several input data sources (listed in the source contribution), including acoustic backscatter, bathymetry, seismic-reflection profile interpretations, bottom photographs, and sediment samples. In order to create the interpretation, first the polygon shapefile of the Massachusetts coast (1:25,000) OUTLINE25K_POLY (http://www.mass.gov/anf/research-and-tech/it-serv-and-support/application-serv/office-of-geographic-information-massgis/datalayers/outline.html) was reprojected from Massachusetts State Plane NAD83 to WGS84 UTM Zone 19N using ArcMap (version 9.3): ArcToolbox -- Data Management Tools -- Projections and Transformations -- Feature -- Project. The polygon was edited so that it enclosed Buzzards Bay and surrounding coastal embayments. The edited shapefile was imported to a file geodatabase as a feature dataset. Then physiographic zone polygons were created using 'cut polygon' and 'auto-complete polygon' in an edit session. In general, polygon editing was done at scales between 1:5,000 and 1:20,000, depending on the size of the traced feature and the resolution of the source data. Separate polygons exist where the adjacent physiographic zones are the same but have different confidence levels, high or low. The following numbered steps outline the workflow of the data interpretation. 1. Backscatter intensity data (available at 1 m resolution) was the first input. Changes in backscatter amplitude were digitized to outline possible changes in sea-floor texture on the basis of acoustic return. Areas of high backscatter (light colors) have strong acoustic reflections and suggests boulders, gravels, and generally coarse sea-floor sediments. Low-backscatter areas (dark colors) have weak acoustic reflections and are generally characterized by finer grained material such as muds and fine sands. 2. The polygons were then refined and edited using gradient, rugosity, and hillshaded relief images derived from interferometric and multibeam swath bathymetry and (available at 10 m resolutions). Areas of rough topography and high rugosity are typically associated with rocky areas, while smooth, low-rugosity regions tend to be blanketed by fine-grained sediment. These bathymetric derivatives helped to refine polygon boundaries where changes from primarily rock to primarily gravel may not have been apparent in backscatter data, but could easily be identified in hillshaded relief and slope changes. 3. The third data input (where available) was the stratigraphic interpretation of seismic-reflection profiles, which further constrained the extent and general shape of sea-floor sediment distributions and rocky outcrops, and also provided insight concerning the likely sediment texture of the feature on the basis of pre-Quaternary, glacial or post-glacial origin. Seismic lines and the surficial geologic maps derived from them and used here as input data were collected at typically 100-meter spacing, with tie-lines generally spaced 1-km apart. 4. After all the sea-floor features were traced from the geophysical data, a new field was created in the shapefile called 'sed_type'. Bottom photographs and sediment samples were used to define sediment texture for the polygons using Barnhardt and others (1998) classification. Some polygons had more than one sample, and some polygons lacked sample information. For multiple samples within a polygon, the dominant sediment texture (or average phi size) was used to classify sediment type (often aided by the 'data join' sediment statistics described in a later processing step). In rocky areas, bottom photos were used in the absence of sediment samples to qualitatively define sediment texture. Polygons that lacked sample information were texturally defined through extrapolation from adjacent or proximal polygons of similar acoustic character that did contain sediment samples. 325 samples of the over 10,950 total within the study area were analyzed in the laboratory for grain size. Samples with laboratory grain size analysis were preferred over visual descriptions when defining sediment texture throughout the study area. Bottom photo stations are typically around 2-km apart, and the density of sediment samples varies throughout the study area, with an average of 1.14 samples per square km, while rocky areas have almost no sediment samples. Person who carried out this activity:
    David S. Foster
    U.S. Geological Survey
    Geologist
    U.S. Geological Survey
    Woods Hole, MA
    USA

    508-5488700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov
    Data sources used in this process:
    • All
    Date: 2013 (process 2 of 7)
    After all the traced features were mapped, new fields were created in the shapefile called 'Pzone_name' and 'area', and the sea floor was characterized for each polygon on the basis of physiographic zones descriptions of Kelley and others (1998). In addition to physiographic zones defined by Kelley and others (1998), we defined the following physiographic zones: coastal embayment; ebb tidal delta; dredged channel; and dredge spoil. Area in square kilometers was defined using the calculate geometry function from the attribute table using the data frame projection (UTM Zone 19N, WGS84). Person who carried out this activity:
    David S. Foster
    U.S. Geological Survey
    Geologist
    U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov
    Data sources used in this process:
    • All
    Date: 2013 (process 3 of 7)
    Finally, a feature dataset was generated inside a geodatabase (ArcCatalog version 9.3.1), and new topology rules were established to make sure that there were no overlapping polygons or accidental gaps between adjacent polygons. The topology error inspector (ArcMap version 9.3.1) was used to find topology errors and fix them. Overlapping polygon errors and gaps were fixed. Area fields were generated automatically for all polygons in the geodatabase. The data were then exported to a shapefile and the polygons were reprojected from UTM Zone 19N, WGS84 to GCS WGS84. Person who carried out this activity:
    David S. Foster
    U.S. Geological Survey
    Geologist
    U.S. Geological Survey
    Woods Hole, MA
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov
    Data sources used in this process:
    • All
    Date: 12-May-2016 (process 4 of 7)
    Edits to the metadata were made to fix any errors that MP v 2.9.32 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Empty fields were deleted. Links to the data were fixed. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 5 of 7)
    USGS Thesaurus keywords added to the keyword section. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 18-Nov-2019 (process 6 of 7)
    Crossref DOI link was added as the first link in the metadata. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 08-Sep-2020 (process 7 of 7)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Kelley, J.T., Barnhardt, W.A., Belknap, D.F., Dickson, S.M., and Kelley, A.R., 1998, The Seafloor Revealed: The Geology of the Northwestern Gulf of Maine Inner Continental Shelf: Maine Geological Survey Open-File Report 96-6, Maine Geological Survey, Natural Resources Information and Mapping Center, Augusta, Maine.

    Online Links:

    McMullen, K.Y., Paskevich, V.F., and Poppe, L.J., 2011, GIS data catalog (version 2.2), in Poppe, L.J., Williams, S.J., and Paskevich, V.F., eds., 2005, USGS East-coast Sediment Analysis: Procedures, Database, and GIS Data: Open-File Report 2005-1001, U.S. Geological Survey, Reston, VA.

    Online Links:

    Ford, K.H., and Voss, S.E, 2010, Seafloor Sediment Composition in Massachusetts Determined Using Point Data: Massachusetts Division of Marine Fisheries Technical Report TR-45, Massachusetts Division of Marine Fisheries, New Bedford, MA.

    Online Links:


How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    These data were produced qualitatively from acoustic and sample data with varying resolutions. Horizontal uncertainty associated with sample collection especially, can be quite high (100 meters or more), much higher than positional uncertainty associated with acoustic data (usually less than <10 of meters). The date of sample collection and ship station positioning all contribute to sample position uncertainty. These qualitatively derived polygons outlining sea floor features are estimated to be within 50 meters, horizontally, but locally may be higher on basis of sample information alone.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    These physiographic zones are defined for areas where source data exists. In general, gaps in the coverage coincide with gaps in the source data. However, some small data gaps were interpreted through extrapolation. Areas of lower data quality and incomplete coverage are noted in a data confidence attribute field.
  5. How consistent are the relationships among the observations, including topology?
    These data were drawn and vetted for accuracy using the source input rasters and point sample data described in the processing steps and source contributions. Overlapping features and unintentional gaps within the survey area were identified using the topology checker in ArcMap (version 9.3.1) and corrected or removed.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Not to be used for navigation. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information. Additionally, there are limitations associated with qualitative sediment mapping interpretations. Because of the scale of the source geophysical data and the spacing of samples, not all changes in sea floor texture are captured. The data were mapped between 1:5,000 and 1:20,000, but the recommended scale for application of these data is 1:25,000. Not all digitized sea floor features contained sample information, so often the sea floor texture is characterized by the nearest similar feature that contains a sample. Conversely, sometimes a digitized feature contained multiple samples and not all of the samples within the feature were in agreement (of the same texture). In these cases the dominant sediment texture was chosen to represent the primary texture for the polygon. Samples from rocky areas often only consist of bottom photographs, because large particle size often prevents the recovery of a sediment sample. Bottom photo classification can be subjective, such that determining the sediment type that is greater than 50% of the view frame is estimated by the interpreter and may differ among interpreters. Bottom photo transects often reveal changes in the sea floor over distances of less than 100 m and these changes are often not observable in acoustic data. Heterogeneous sea floor texture can change very quickly, and many small-scale changes will not be detectable or mappable at a scale of 1:25,000. The boundaries of polygons are often inferred based on sediment samples, and even boundaries that are traced based on amplitude changes in geophysical data are subject to migration. Polygon boundaries should be considered an approximation of the location of a change in texture.
  1. Who distributes the data set? (Distributor 1 of 1)
    David S. Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2271 (voice)
    508-457-2310 (FAX)
    dfoster@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    These data are available in Environmental Systems Research Institute (Esri) shapefile format. The user must have software capable of importing and processing this data type.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
U.S. Geological Survey
Attn: David S. Foster
Geologist
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 x2271 (voice)
508-457-2310 (FAX)
dfoster@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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