This map showcases 2004-2006 satellite imagery of Chuuk taken by Digital Globe’s QuickBird satellite. The data were purchased and processed by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS). The image shown here is in natural color. Image portions that fall outside the barrier reef of Chuuk are omitted from the map.
This map showcases 2009 satellite imagery of Chuuk taken by Digital Globe’s QuickBird satellite. The data were purchased and processed by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS). The image shown here is in natural color. Image portions that fall outside the barrier reef of Chuuk are omitted from the map.
This map showcases 2014 satellite imagery of Chuuk taken by Digital Globe’s WorldView-2 satellite. The data were purchased and processed by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS). The image shown here is in natural color. Image portions that fall outside the barrier reef of Chuuk are omitted from the map.
This map showcases satellite imagery of Chuuk taken between 2015 and 2016 by Digital Globe’s WorldView-2 satellite. The data were purchased and processed by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS). The image shown here is in natural color. Image portions that fall outside the barrier reef of Chuuk are omitted from the map.
This map showcases satellite imagery of Chuuk taken between 2018 and 2019 by Digital Globe’s WorldView-2 satellite. The data were purchased and processed by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS). The image shown here is in natural color. Image portions that fall outside the barrier reef of Chuuk are omitted from the map.
This map shows the shoreline and the land area of all islands in Chuuk Lagoon and on the barrier reef. It actually contains two datasets: the shoreline itself were created by Island Research & Education Initiative (iREi) (2020). The shoreline was manually digitized based on Worldview-2 satellite imagery from Digital Globe (2014 and 2018-2019 for selected urban areas) provided by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS) while the reef areas were generally based on the Digital Line Graphs (DGLs) by U.S. Geological Survey (USGS) but shifted and adjusted to follow current imagery better.
This map shows the shoreline and the land area of all islands in Chuuk Lagoon and on the barrier reef. It actually contains two datasets: the shoreline itself and Chuuk base layer. Both were created by Island Research & Education Initiative (iREi) (2020). The shoreline was manually digitized based on Worldview-2 satellite imagery from Digital Globe (2014 and 2018-2019 for selected urban areas) provided by U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS) while the reef areas were generally based on the Digital Line Graphs (DGLs) by U.S. Geological Survey (USGS) but shifted and adjusted to follow current imagery better. The base layer distinguishes high islands from low islands, lagoon reefs from lagoon bottom, and barrier reef flats from deeper and permanently submerged parts of the barrier reef.
This map represents the topography of islands in Chuuk Lagoon. It shows elevation contour lines at 10-meter intervals. Depicted in greyscale, the contour lines were derived by Island Research & Education Initiative (iREi) (2020) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968 and the shoreline dataset representing the zero contour line.
This map represents the topography of islands in Chuuk Lagoon. It shows elevation contour lines at 10-meter intervals. The contour lines are depicted in a range of colors corresponding to elevations from the shoreline to 780 m above sea level. They were derived by Island Research & Education Initiative (iREi) (2020) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968 and the shoreline dataset representing the zero contour line.
This map represents the topography of islands in Chuuk Lagoon. It shows elevation contour lines at 50-meter intervals. Depicted in greyscale, the contour lines were derived by Island Research & Education Initiative (iREi) (2020) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968 and the shoreline dataset representing the zero contour line.
This map represents the topography of islands in Chuuk Lagoon. It shows elevation contour lines at 50-meter intervals. The contour lines are depicted in a range of colors corresponding to elevations from the shoreline to 780 m above sea level. They were derived by Island Research & Education Initiative (iREi) (2020) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968 and the shoreline dataset representing the zero contour line.
This map shows the elevation of terrain of islands in Chuuk Lagoon. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968. The DEM was classified into elevation intervals and colored based on elevation in meters above sea level.
This map shows the elevation of terrain of islands in Chuuk Lagoon. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968. The DEM is depicted as a range of colors based on elevation in meters above sea level.
This map shows the elevation of terrain of islands in Chuuk Lagoon. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968. The DEM is depicted as shades of gray based on elevation in meters above sea level.
This map shows the relief of terrain of islands in Chuuk Lagoon. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968. The dataset was derived using the so-called hillshade function that creates an illusion of viewing terrain in 3D.
This map shows the elevation and relief of terrain of islands in Chuuk Lagoon. It consists of two separate datasets, both of which were derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968. The two datasets are a DEM classified into elevation intervals and colored and a hillshade layer that creates an illusion of viewing terrain in 3D. Combined, they produce hypsometric-tinted shaded relief seen on the map and give illusion of viewing terrain in 3D while also providing elevation information.
This map shows the slope aspect of the terrain of islands in Chuuk Lagoon. Slope aspect is the compass direction in which a particular slope faces. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created U.S. Geological Survey based on topography compiled in 1968.
This map shows the steepness of slope on islands in Chuuk Lagoon. The steepness here is expressed in degrees and illustrated by means of a color gradient. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968.
This map shows the steepness of slope on islands in Chuuk Lagoon. The steepness here is expressed in terms of percent rise and illustrated by means of a greyscale gradient. The dataset was derived by Island Research & Education Initiative (iREi) from a 10-meter resolution Digital Elevation Model (DEM) created by U.S. Geological Survey based on topography compiled in 1968.
This map shows the location of survey control points established on the islands of Chuuk Lagoon. The data layer was created by Island Research & Education Initiative (iREi) (2019) by creating a subset of the Digital Line Graphs (DGLs) by U.S. Geological Survey (USGS). The dataset was shifted to follow current imagery better. The exact location in this dataset may not be accurate.
This map shows the most prominent and unique natural landforms, such as rock and reef formations and other geological sites of interest in Chuuk Lagoon. This layer was created by Island Research & Education Initiative (iREi) (2020) using field observations and location data from a variety of sources. The selection of included sites is not definitive and the layer will be appended with more fieldwork in the future.
This is a topographic map of Chuuk. It is made from a raster document actually comprised of eight separate topographic maps, 1:25,000 scale, published by the U.S. Geological Survey (1996-1997) as paper document. The maps were later scanned and georeferenced to create what is commonly referred to as Digital Raster Graphics (DRGs). Island Research & Education Initiative (iREi) (2020) converted the original PDF files to GeoTiffs. The scanned topographic maps are commonly referred to as Digital Raster Graphics (DRGs). In the map shown here, portions of the DRG that fall outside the barrier reef of Chuuk are omitted.
This map shows the basic soil types of the islands in Chuuk Lagoon. The original dataset was created by the U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS) (1983) as part of the soil survey of the Islands of Truk, Federated States of Micronesia at 1:10,000 scale. Soil map unit delineations were confirmed as accurate during a subsequent evaluation (1999). The data layer was created by Island Research & Education Initiative (iREi) (2019) by extracting and formatting a subset of the Gridded Soil Survey Geographic (gSSURGO) Database for Federated States of Micronesia (2019) created by USDA-NRCS.
This map represents levels of erosion hazard in different areas of Chuuk. The data were created by the U.S. Department of Agriculture (USDA) - Natural Resources Conservation Service (NRCS) and are included in the same dataset as the one used for the basic soil types map. Erosion hazard in different areas is estimated based on the local soil type, terrain slope, and other parameters.
This map shows the general geology of the islands in Chuuk Lagoon. The data layer was created by Island Research & Education Initiative (iREi) (2020) by scanning, georeferencing, and digitizing a set of paper maps prepared under the direction of the Engineer, Hq AFFE/8A, by the US Army Map Service, Far East; based on field investigations by the Military Geology Branch, Intelligence Division, Office of the Engineer, Hq, US Army Japan. Fieldwork conducted in 1954-1955 by JT Stark, RL Hay, HG May, and ED Patterson; maps are titled "Geology, Truk Islands" and were compiled in 1957 by photogrammetric (multiplex) methods.
This map shows the general physiography of the islands in Chuuk Lagoon. The data layer was created by Island Research & Education Initiative (iREi) (2019) by scanning, georeferencing, and digitizing a set of paper maps prepared under the direction of the Engineer, Hq AFFE/8A, by the US Army Map Service, Far East; based on interpretations for road and airfield constructions by Harold G. May, 1954-1955; maps are titled "Suitability for Road and Airfield Construction Map, Truk Islands" and were compiled in 1957 by photogrammetric (multiplex) methods.
This map shows the locations of prominent peaks on the high islands in Chuuk Lagoon. This data layer was developed by Island Research & Education Initiative (iREi) (2020) by extracting a subset of the U.S. Geological Survey's Geographic Names Information System (GNIS). Note that the actual names contained in the dataset are copied exactly as they are in GNIS and are not necessarily correct or aligned with Chuukese orthography.
This map shows the locations of prominent caves on Chuuk. The data layer was created by Island Research & Education Initiative (iREi) (2020) by manually digitizing features from the topographic map of Chuuk, 1:25,000 scale, published by the U.S. Geological Survey (1996-1997). The locations are approximate and none were verified in the field. Along with the location, we noted the approximate directions of the caves' openings, as marked on the topographic maps. It should be noted that high islands of Chuuk Lagoon have no karst terrain, so all caves found there are in volcanic units. They include both natural caves (lava tubes and cliff-base rock shelters) and human-made caves (mostly excavated for defensive purposes by the Japanese military during World War II).
