Adding Seabed True Color to the Virtual Globe

Since the late 1940’s thousands of sediment cores have been extracted from the global ocean floor. In the process of describing these cores, the color of the sediment has often been recorded using the Munsell Soil color scheme. This observation has been routine for >14,000 cores in the Deep-Sea Sample Repository at the Lamont-Doherty Earth Observatory of Columbia University. The text descriptions were parsed and processed to extract the Munsell code for the uppermost sediment layer in each core. The code was then converted to red, green, blue triplets so that a dot at the location of each seabed sample could be colored in map view on a computer monitor. The sediment color has also been extracted from thousands of other samples in the dbSEABED database and USGS databases. Sediment color is influenced by many parameters, but most notably by the carbonate content, the level of dissolved oxygen in the bottom water and the burial rate. The carbonate content has been measured in a substantial subset of the core tops, and a global grid at 1 degree node spacing is available to assist the interpolation of the seabed color onto a uniform grid. The seabed dissolved oxygen content has also been gridded from physical oceanographic stations. Using these and other proxies (e.g., seafloor depth, slope, physiographic boundaries, carbonate lysocline, surface ocean productivity, seafloor age, etc.), we have begun to construct a comprehensive image of the seabed in its true color for our GeoMapApp and Virtual Ocean tiles. The color of the seabed will ultimately compliment the color of the land accomplished by JPL/NASA in their Blue Marble tile set. The steps taken, problems encountered and the preliminary results will be presented in the poster.