The NEGIS N1 3D horizon is located at the onset of Greenlands Northeast Greenland Ice Stream and has an age of 7.3 ± 0.2 ka (thousand years). NEGIS N1 covers an area of ∼ 250 x 90 km and is centred at the EastGRIP drill site. The geometry of this 3D horizon shows a variety of complex and high number of folds, which are increasing in ice-flow direction. A number of short-wavelength folds (100-500 m long and with amplitudes up to 100 m high) extend almost from the ice divide downstream along the shear zone of NEGIS.

The 3D horizon and traced radar lines are provided in four different data formats:1. ASCII format of the point cloud of the 3D horizons (meshes.dat) or traced radar lines (line.dat) in the xyz format, where x and y represent the coordinates and z the elevation in meters.2. Digital Elevation Models (DEMs) in the GeoTIFF (.tif) and NetCDF (.nc) format of the 3D horizons (meshes). The DEMs have a cell size of 50 m.3. GoCAD (Geological Objects: The 3D horizons (meshes) are stored in triangulated surfaces (.ts) and the traced radar lines as polylines (.pl).