A continuous margin of the Greenland Ice Sheet for the Little Ice Age maximum

The LIA extent was identified and extracted using known techniques of band combinations in remote sensing but applied to look at a terrestrial landscape through a new lens. The marginal zone of the LIA is denoted by little or no vegetation, disturbed sediment, moraines, trimlines, little or no soil development and the exposed rock surfaces are unweathered. Sentinel 2 images were downloaded from USGS Earth Explorer from July- September 2021 to show the peak vegetation season. Scenes with less than 10% cloudiness were chosen. The band combination to identify the LIA extent is B11 (Short Wave Infrared: SWIR), B8 (Near Infrared: NIR), and B2 (Blue). 

The Reclassify Spatial Analyst tool was used to perform an unsupervised classification and geoprocessing to change the value in a raster, from a range to a single value. Image classification is the conversion of a multi-band raster image, such as Sentinel-2, to a single-band raster with defined categories to represent the desired land cover.

The mask is a visual map of the entire area covered by the GrIS during the LIA maximum. 

 The LIA mask was created in projection Stereographic North (ESPG3413) to match the BedMachine product. The data is available for use in 30 x 30m, 150 x 150m and 1 x 1km resolutions in NetCDF Files.  It is also available as .tif in 30 x 30m, 150 x 150m and 1 x 1km resolutions and a .shp and .kmz files to be useable in modelling, GIS (Arc & QGIS), and Google Earth.