This shapefile represents batymetric polygons at -4000 meters depth. These data were created from created from SRTM Plus. Isobaths surrounding islands, seamounts, and near other steep slopes received considerable manual generalization to improve legibility. This layer is part of the Natural Earth Collection (v.2.0.0). Natural Earth is a public domain map dataset available at 1:10m, 1:50m, and 1:110 million scales. Featuring tightly integrated vector and raster data, with Natural Earth you can make a variety of visually pleasing, well-crafted maps with cartography or GIS software. Kelso, N.V. and Patterson, T. (2012). World Bathymetry, -4000 Meter Depths, 1:10 million (2012). Made with Natural Earth, online at http://www.naturalearthdata.com.