The article ‘GEBCO and Deep Water’ (see page 7) by David –Monahan draws attention to the need for more deep-survey data, implying not only the discipline of having equipment running whilst in transit but also that of submitting data collected. It is good to realise that it is not just science or the military who are the driving forces behind deep-water survey; an estimated 40%-50% of deepwater multi-beam systems are commercially owned/operated.
A structure facilitating sharing and analysis of available data could save a lot of work and offer added value if used in combination with other data. The increasing use of (web-based) GIS should enable such things, see the article ‘2D/3D Web-Mapping’ by Peio Elissalde (from page 17) and articles by Declan Dunne in our September 2006 and November 2006 issues on the use of these web-based possibilities.
One way to gain more data at little extra cost is to use ships of opportunity. The issue is not only collecting data but also storing and migrating this to the next data storage media. The cost of timely migrating and storage is a fraction of collection time. A lesson learned from previous decades is not to throw away data thinking you do not have the computing power to analyse it. Our data is never too dense. If we cannot handle it now, we need just keep it stored and accessible: future developments will cope with it.
The ‘Kroonvlag’ project undertaken by the Vening Meinesz Laboratory of The Netherlands provides an example of the use of ships of opportunity, vulnerability if older data is not adequately preserved, and analysis of data using new techniques. Over the period spanning the 1960s and 1980s, a Dutch shipping company in regular service between Europe and the West Indies collected a valuable dataset of single-channel seismic, magnetic, and sometimes gravity, data by sailing equipped with the necessary equipment. It cost the Geological Survey of Canada enormous recent effort to recover this dataset, which had been stored on nine-track magnetic tapes. After a tedious process they finally managed to do so, leading to visualisation of the data using modern gridding and imaging techniques that were not available at the time of collection.
Enjoy reading,
Leeke van der Poel, from Tobago Cays/Horse Shoe Reef
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