Since about 1773 when the British captain James Cook first crossed
the Antarctic Circle a vast amount of scientific data on conditions
around Antarctica have been collected. Many of these data originate
from the hundreds of Antarctic expeditions of exploration and commerce
that have taken place. The data exist largely in the form of maps,
charts and logbooks, a large ... number of which not only contain data
about new discoveries of land, but also about the extent of ice
shelves and the occurrence of sea ice and ice-bergs in the Antarctic
seas. Detailed records of ice limits were kept because ice posed a
great danger to the ships and prevented whalers and seal hunters from
reaching their hunting grounds.
At the present time, a great deal of research is being carried out
into the dynamics of Antarctic ice, both causes and
consequences. However, it was not until the 1950's that the systematic
and long-term recording of meteorological data and ice conditions in
the Antarctic region really started. This period is too short to
reliably detect changes and trends in ice extent around Antarctica.
By studying old maps and logs, however, the period for which data
is available can be significantly extended. Although scattered in
time, information from historic maps can provide valuable insight in
how the present ice situation around Antarctica compares to the
situation from 1800 onward.
The information collected under this project is being used to
compile an integrated digital dataset. Spatial information is stored
and analyzed in a Geographical Information System (GIS), facilitating
the systematic comparison of map data. Information from logbooks and
journals are compiled in a database and linked to geographic locations
or features. In this way, an overview of the dynamics of the edges of
the Antarctic floating ice over the study period is being created.
In this study, data covering Antarctica as a whole will be taken
into account. The main focus, however, is on the Weddell Sea (Ronne
and Larsen Ice Shelves) and on the Ross Sea (Ross Ice Shelf). Because
of their relatively good accessibility, these areas were frequently
visited and charted during commercial and scientific expeditions.