PhysicalSample in the state of Alaska

The map service incorporates submarine slides. Slides are presented as polygons in addition to boundaries of the slides. The data has been compiled from several sources, with differing details. The main source for the slides on the Norwegian continental shelf is the Seabed project (Norwegian Deepwater Programme, Seabed project Phase II. Mid-to Late Cenozoic Geomodel of the Mid-Norwegian Continental Margin. Atlas volume (Report no. SP2-02-FS-01R-00003-04); By Fugro Survey Ltd., BGS, NGU). For slides in the other countries, the COSTA project (COSTA - Continental Slope Stability, 2004. Ed. J. Mienert. Marine Geology 213, 1-4, pp. 1-504) is the main source. Minor sources include various scientific publications and the Norwegian MAREANO project. Source information is available through the info button in the map service.

A sinkhole is a natural depression or hole in the Earth's surface which may have various causes. Most natural sinkholes are caused by the chemical dissolution of water-soluble carbonate rocks or gypsum. Sinkholes may vary in size from 1 to 600 m both in diameter and depth. Sinkholes may be formed gradually or by sudden collapse and are found worldwide in ‘karst areas.’ Karst areas are not unique to Nova Scotia; in fact, they occur in over a quarter of the earth’s surface. As a result, there are well-established methods for reducing karst risks. These include actions that can be taken both at the planning and construction stage of a project, as well as on-going actions that reduce the risk of future sinkhole formation. This dataset was developed to show areas of Nova Scotia where there is a relatively high-medium-low risk of encountering karst and naturally occurring sinkholes caused by soluble bedrock.

NGU Superficial geology - OneGeology-Europe WP3. Mapscale 1:1 M. This service shows surface geology, structures and bedrock defined by rock types and ages. The bedrock areas are also assigned to tectonic units. The map is composed of data resulting from several mapping campaigns, performed over decades, compiled and archived in digital format, published or prepared in manuscript format between 1989 and 2001. Due to the variation of quality and scales of different mapping campaigns the level of accuracy in the underlying national database is variable. The database is designed for presentation in the 1:1M scale.