Digital Bottom Topography

Gridded bathymetric data sets of the Baltic Sea and the Belt Sea were sampled from nautical sea charts by Seifert and Kayser (1995). These data have been requested and applied by many scientists for various research projects, showing that there is a common need for such data. Motivated by the widespread application and by the availability of further bathymetric information (see Table 20.8) improved versions of the data sets were produced and published by Seifert et al. (2001). The data are freely accessible for scientific use from the homepage of the Leibniz Institute for Baltic Sea Research. 

We will give a short overview of the recent status of the data sets, which summarises basic facts necessary for the application of the data. A detailed description of the data compilation and evaluation is also available online (http //www.io-wamemuende.de/research/iowto-po resamphng.html). 

The indices 1 and 2 refer to the coordinates of the two data sets, iowtopo 1 and iowtopo2, where the resolution of the grids corresponds to approximately 1 km and 2 km. 

For the evaluation of the resulting Baltic bathymetry it should be noted that the original data sets have different characteristics, see Table 20.8. 

Data sources The data were mostly taken from nautical sea charts of different scales, but include also digitized soundings. 

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Isobaths.zip contains ASCII files of isobath polygons in form of blank files (.bln) for the depths of 10,20,30,40,50,60,70,80,90,100,120,140,160,180,200,250,300, and 400 m compiled from the digital bottom topography of Seifert et al, (2001 Section 20.2,5), Each file contains several polygons, starting with the particular number of polygon vertices, followed by its sequence of (Ion, lat) coordinate pairs. 

This book explicitly supports an open data policy for the Baltic Sea region, in particular by its Digital Supplement CD with a large number of key parameters provided as long-term series, together with reference data, such as shorelines, bottom topography, or the equations... 

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