These data represent a series of mean high water shorelines collected at Assateague Island National Seashore (ASIS), appended into one file geodatabase (1993-2022). Post-2022 surveys can be found on https://asis-nps.opendata.arcgis.com/. The features have been assembled / collected in support of the Northeast Coastal & Barrier Inventory and Monitoring Network's Ocean Shoreline Position Monitoring Program. The shoreline surveys are collected using a sub-meter GPS receiver mounted on an ATV or UTV starting in August of 1993 continuing through present day. Shorelines are grouped in Feature Datasets by the season the data were collected. Depending on the time of year and intended purpose, some surveys contain ocean, inlet and bay shorelines, while some surveys only contain ocean shorelines.

These data represent a series of mean-high water shorelines collected at Assateague Island National Seashore (ASIS), appended into one spatial dataset. The features have been assembled / collected in support of the Northeast Coastal & Barrier Inventory and Monitoring Network's Ocean Shoreline Position Monitoring Program. Surveys along the ocean shoreline were collected by driving a 4-wheel drive vehicle or walking at a relatively constant speed along the identified high tide swash line. For the purposes of this monitoring program, the actual ocean "shoreline" was defined as the average position of the most recent high tide, evidenced by the obvious wet/dry sand line or deposited wrack. The GPS/GNSS receiver was configured to record positions at a very short interval (at least 1 position every 10 meters) for the best representation of the shoreline position. Depending on the time of year and intended purpose, some surveys contain ocean, inlet and bay shorelines, while some surveys only contain ocean shorelines. Additionally, some surveys collected prior to 2003 do not contain FGDC-compliant metadata records. This dataset contains shoreline features collect between Winter of 1994 and Spring 2025.

These data represent a series of mean high water shorelines collected at Assateague Island National Seashore (ASIS), appended into one spatial dataset. The features have been assembled / collected in support of the Northeast Coastal & Barrier Inventory and Monitoring Network's Ocean Shoreline Position Monitoring Program. Surveys along the ocean shoreline were collected by driving a 4-wheel drive vehicle or walking at a relatively constant speed along the identified high tide swash line. For the purposes of this monitoring program, the actual ocean "shoreline" was defined as the average position of the most recent high tide, evidenced by the obvious wet/dry sand line or deposited wrack. The GPS/GNSS receiver was configured to record positions at a very short interval (at least 1 position every 10 meters) for the best representation of the shoreline position. Depending on the time of year and intended purpose, some surveys contain ocean, inlet and bay shorelines, while some surveys only contain ocean shorelines. Additionally, some surveys collected prior to 2003 do not contain FGDC-compliant metadata records. This dataset contains shoreline features collect between August of 1993 and Fall 2022.

These files contain topographic profiles collected at ASIS through the Spring 2025 field season

These files contain topographic profiles collected at ASIS through the Spring 2025 field season

The dynamic nature of coastal areas is a defining characteristic, influencing nearly every aspect of their ecology. Fundamentally disturbance driven systems, coastal shorelines and their endemic biota are continually shaped by physical forces on a time scale vastly accelerated in comparison to mainland systems. Because of the rapid pace and scope of change, long term monitoring is crucial towards understanding natural shoreline conditions as well as anthropogenic influences. These data represent a series of mean high-water shorelines collected at Assateague Island National Seashore (ASIS), Cape Cod National Seashore (CACO), Fire Island National Seashore (FIIS), Gateway National Recreation Area (GATE), George Washington Birthplace National Monument (GEWA), and Sagamore Hill National Historic Site (SAHI). The features have been assembled/collected in support of the Northeast Coastal & Barrier Inventory and Monitoring Network's Ocean Shoreline Position Monitoring Program. Surveys along the ocean shoreline were collected by driving a 4-wheel drive vehicle or walking at a relatively constant speed along the identified high tide swash line. For the purposes of this monitoring program, the actual ocean "shoreline" was defined as the average position of the most recent high tide, evidenced by the obvious wet/dry sand line or deposited wrack. The GPS/GNSS receiver was configured to record positions at a very short interval (at least 1 position every 10 meters) for the best representation of the shoreline position. Depending on the time of year and intended purpose, some surveys contain ocean, inlet and bay shorelines, while some surveys only contain ocean shorelines.

These files contain topographic profiles collected at ASIS through the 2022 field season

These files contain topographic profiles collected at ASIS through the 2020 field season

These files contain topographic profiles collected at ASIS through the 2020 field season

ASCII XYZ point cloud data were produced from remotely sensed, geographically referenced elevation measurements acquired cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over northern Assateague Island National Seashore using the first-generation National Aeronautics and Space Administration (NASA) Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.