APPENDIX

Proposed Data Specification for Arctic Bathymetric Compilation

This Appendix suggests a data format for contributions of bathymetric observations.

A data set from each cruise or expedition (e.g. ice island) should be stored in its own ASCII file. The file should be assigned a six-character file name that identifies both the platform (Oden, Polarstern...) and the year of acquisition (e.g. Oden96.dat; Prst95.dat). Each data point should appear in the file in time sequential order, occupying one line in the file in the following format:

Timetag Longitude Latitude Depth

The Timetag should be of the form: yyyy+ddd:hh:mm:ss where yyyy is the year of acquisition. The date is indicated by the Julian day ddd, which ranges from 001 to 365 or 366. The time hh:mm:ss ranges from 00:00:00 to 23:59:59. Longitude should be geodetic (0 degrees to 360 degrees increasing in the easterly direction), Latitude should range from 60 degrees N to 90 degrees N; each position coordinate should be reported to the full precision that can be attributed to the navigation source. Depth should be reported in metres.

To assist with qualification and documentation of the compilation, contributors are requested to provide certain collateral information with each data set. This additional information will ensure that data sets are properly attributed; it will also comprise a heritage that can be used to eliminate redundant measurements, to assess the quality of the data, and to represent and rescale data in a uniform manner for crossover analysis and error identification.

Accordingly, for each data set contributors are requested to prepare a supplemental file which uses a similar six character descriptor (e.g. Oden96.doc or Prst95.doc) and which contains: the type and estimated accuracy of navigation; the sound velocity that was used to convert two-way acoustic travel time to depth; a summary of post-cruise processing (including the application of sound velocity corrections); a listing of any known defects or errors.

Compiling the Arctic bathymetry will be a major undertaking, but the availability of supplemental files will simplify the processes of evaluating and integrating the many and diverse data sets that are anticipated. The accumulated documentary information will be included as part of the final data release to assist investigators who might wish to work with this data in the future.

Data may be forwarded on digital media to one of the following addresses, or alternatively by direct transfer via the Internet to a subdirectory in one of the Anonymous FTP accounts shown below (in which case contributors should also alert recipients of the transfer):

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