This CD

TECHNICAL INFORMATION: THE BATHYMETRIC MAPS

The enclosed bathymetric and topographic maps are based on 2,275,808 data points. Of these, 1,312,788 (57.7 %) are water-depth points in the lake, 75,685 (3.3 %) are coastline points, and 887,335 (39 %) are onshore elevation data. The water-depth points have been obtained from re-compiled and depth-corrected acoustic sounding data, merged with additional bathymetric information (e.g. from echosounding measurements and seismic profiling).

distribution map of data points in .pdf format
distribution map of data points in .jpg format

Coordinates of the data points are in Mercator projection, WGS 1984 Ellipsoid. The units of measure are meters rounded-off integer. The true-scale latitude for all the generated maps is 53° 00’ N.

The bathymetric and topographic maps were generated using the EarthVision^® software (version 5.1).

The data points were combined into a 2D grid, which -in fact- represents the merging of two separate grids with initially different grid spacing (depending on the distribution and density of the original data points). EarthVision^® used a 2D minimum tension gridding algorithm to calculate a smooth surface, which is the best fit to the input data values, by using a bicubic spline technique.

This 2D grid was then used by EarthVision^® to obtain the following set of maps and data sets of the morphology of Lake Baikal and its surroundings:
-          Contour bathymetric map
-          Colour bathymetric map
-          Slope map
-          Shaded-relief map
-          Colour shaded-relief map
-          3-D images
-          Morphometric calculations of surfaces and volumes

The contour maps still exhibit a number of small artifacts (i.e. isolated closed contours, especially at crests and along sudden slope changes). This are due to some technical characteristics of the applied gridding algorithms.

TECHNICAL INFORMATION: THE CD-ROM

The CD-Rom consists of a series of Hypertext Markup Language (HTML) pages and hypertext links, located in the "Web" directory of the CD-Rom. The base page, is the file "start.html" located in the main directory of the CD-Rom. To use the data set on this CD-Rom, load the file "start.html" using an HTML browser such as Netscape^® or Microsoft Internet Explorer^®. All text materials related to the data set are accessible directly from the base page.

The maps and figures are also accessible from the base page, via hypertext links. By clicking on the links, the corresponding map or figure will be opened in a separate browser window.

Most maps on this CD-Rom exist in two formats:

1. In .pdf format. You need Acrobat Reader^® to open this type of file. Acrobat Reader^® can be downloaded from internet for free,
2. In .jpg image file format, which normally can be viewed using your HTML browser. If not, your PC will ask you which program you wish to use for viewing.

Non-map figures on this CD-Rom usually exist in .jpg image file format only.