Die Bathymetrie der Weltmeere auf einer CD..
GEBCO - General Bathymetric Chart of the Oceans
The General Bathymetric Chart of the Oceans, better known as GEBCO, was
initiated at the turn of the century by Prince Albert I of Monaco and the
First Edition was published in 1903 as a compilation of the 18,000 depth
measurements then available for the world's oceans. Sheets of the succeeding
three editions began to reveal the presence of large scale positive relief
features, such as parts of the mid-ocean ridge system, but they lacked
detail.
...
The Fifth Edition of GEBCO was published by the Canadian Hydro-graphic
Service between 1975 and 1982 with 16 Mercator sheets covering the world
from 72°N to 72°S, on a scale of 1:10 million at the equator, and two polar
stereographic sheets covering the polar regions to 64°N and 64°S respectively,
on a scale of 1:6 million at 75° latitude. Each sheet depicted bathymetric
contours at 200m, 500m and at 500m intervals thereafter, with some sheets
also including contours at other intermediate depths. Tracklines and
outlines of survey boxes were included on the printed sheets to show the
coverage of sounding data available when the contours were drawn.
The GEBCO System
The preparation of the Fifth Edition was a collaborative effort between the
International Hydrographic Organization (IHO)
and the
International Oceanographic Commission (IOC) of Unesco,
with the IHO responsible for coordinating the efforts of
the Hydrographic Offices in its Member States and the IOC responsible for
attracting eminent marine geologists and geophysicists to collaborate in the
work of GEBCO.
...
Die Bathymetrie der Weltmeere auf einer CD..
..bald auch die
Nautischen Karten zur Schiffsnavgation (ECDIS)..
The GEBCO Digital Atlas (GDA)
Creating the GDA
Updating the GDA
Concluding remarks
webnapped at 1997-02-12 from:
http://www.nbi.ac.uk/bodc/gebco/article.html, the
article on the GEBCO Digital Atlas
by Dr Meirion T. Jones of the British Oceanographic Data Centre, 05 May 1995,
and modified by HHz.
In order to establish a digital base for the future updating of GEBCO, and
to provide a more flexible product for users, the GEBCO Guiding Committee
decided in 1983 that the printed sheets of the Fifth Edition should be
digitised.
...
The digitised data from the Fifth Edition have been used to initialise the
GEBCO Digital Atlas (GDA), which will form the base from which future
printed editions of GEBCO will be generated.
The updating of GEBCO through the GDA will be a continual process and the
GDA will be published regularly as a product in its own right.
Without the scale and projection constraints of the printed chart, it is
envisaged that improved bathymetric compilations will be merged into GEBCO
at scales ranging from 1:10 million up to 1:500,000 or better, depending on
the density of the sounding coverage. New data will be "stitched in" so as
to maintain a seamless global data set.
...
The IOC Regional Ocean Mapping Projects will be an important source of new
material and the digitised contours and coast-lines from the International
Bathymetric Chart of the Mediterranean (IBCM) have already been included in
the GDA.
...
For the 1997 edition of the GDA, the southern Atlantic Ocean contours within
the Weddell Sea are taken from the 1:1,000,000 series
"AWI Bathymetric Chart of the Weddell Sea (AWI BCWS)" by the
Alfred Wegener Institute of Polar and Marine Research (AWI), Bremerhaven.
Recent satellite altimetry missions have, of course, provided invaluable
insights into the nature of the topography in waters uncharted by modern
echo-sounders.
However, the detailed mapping of the sea floor will continue to depend on a
small band of scientists across the world who are prepared to apply their
skills to the interpretation of random tracklines of data from a multitude
of sources and with highly variable data quality and coverage.
It is of paramount importance that future research cruises should aim
wherever possible to traverse the gaps in the coverage and to make their
soundings available to the IHO Data Centre.
In the meantime, it is hoped that this first release of the GDA will be the
forerunner of a series of products each delivering progressively improved
bathymetric maps of the world's oceans.