ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

of the largest biogenic ones (their areas are reflected with
the shading of different kinds and colours). There are the
areas of bog complexes of relief (marshes in coasts, molecourses,
ant-hills, marmot-hills, suslik-hills, steppe-marmot-hills,
mirna-relief, termitariums, beavers' complexes,
root-denudation; the areas of «tropical» karst (in connection
with the role of vegetation in this process), the organic
(reef, mangrove, reed) coasts (Kaplin & alii, 1991) and the
areas of relic reef complexes in the continents in the map.
Literature data about the biogenic continental relief is generalized
in this map, also our own observations in some
natural zones are used.
As to mapping of biogenic relief on a large scale, it's proposed
to use qualitative background (colour or shading)
for large forms (relic reefs, beavers' dams and reservoirs )
or unsealed symbols for outstanding ones (as termitariums),
as well as for leading processes of biogenic relief
formation (areas of peat accumulation and bog tussocky
microrelief formation). The use of the dot method is optimum
for mapping of micro- and nanorelief to my mind.
Naturally the drawing such detailed maps on large scale is
possible as a result of painstaking observation of biogenic
relief in regions only (we conduct such kind of observations
in Moscow, Kaluga and Kostroma regions in the Russian
plain). I think the mapping of biogenic relief is necessary
for study of mutual connections between the relief
and organisms in the ecosystems of different classes.
ALDINO BONDESAN
A glaciological map of a small ice shelf
(Hell's Gate Ice Shelf, Terra Nova Bay, Antarctica)
Dipartimento di Geografia G. Morandini, Universita di Padova,
via del Santo 26, 35123 Padova, Italy
The Hell's Gate Ice Shelf (Hgis) is a small ice shelf located
to the south of the Italian Antarctic Station «Terra Nova
Bay». Its total area is more than 70 krn', extending about
17 km north to south and having a maximum width of
about 10 km. It is nourished from the north by the Priestley
Glacier and by the ice flow from Browning Glacier;
to the west it is in connection with the Nansen Ice Sheet.
The Hgis is bounded by the northern Foothills to the east,
Vegetation Island to the north, Inexpressible Island and
Nansen Ice Sheet to the west and the Ross Sea to the
south.
Intense surficial ablation due to the katabatic winds descending
from the Antarctic Plateau and blowing with
great intensity and frequency across the ice shelf is responsible
of the strong uprise of the ice and of the replacement
with marine ice at the bottom, expecially at the front. Because
of its peculiarities Hgis has been a field of research
for glaciologists, geophysicists and metheorologists since
the first Italian antarctic expeditions (1984/85).
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The map, which is descriptive in many aspects, is designed
as a basis for future interpretation of the dynamical behaviour
of the ice shelf. It is based on the field research carried
out during the IX, X and XI Italian Antarctic Expedition,
also as part of the Italo-Belgian joint glaciological research
program. Data from former studies by Italian and
Belgian researchers also greatly contributed to the making
of this map. The only available map of this region was the
U.S. Geological Survey 1:250,000 sheet «Mt. Melbourne».
Also images from satellite and aerial photographs are avai­
1able. The cartographic basis that was adopted for the glaciological
map of Hgis is a mosaic derived from the black
and white aerial photographs of the «Tma 6-11-85» flight
and the «Hell's Gate 8-11-93» flight (approximate scale
1:25,000). The Gps geodetic measurements performed in
1993 year (10 points) allowed the geometric georeferencing
of topographical and morphological features in the
area.
The map combines the photointerpretation of aerial photographs
(1956-57, 1985, 1993) with field survey. The
great detail of the high -quality aerial images and the opportunity
that we had to study and check the various glacial
features directly in the field, under different seasonal
conditions, allowed us to identify properly the different
glacial subsets and covers. Problematic cases were eventually
investigated through ice corings and field studies of
the ice textural characteristics.
The data covered by the map can be organized in the following
groups:
a) snow and firn; b) glacier ice; c) marine ice; d) sea ice; e)
lake ice; f) cones; g) ice cliff h) hydrography (bedieres and
melt water lakes); g) glacial movements and the related
surficial forms (pressure ridges, ice bulges and domes); h)
main foliations; i) main crevasses and cracks in fast ice; l)
ice foot, fast ice margin and the hummocked ice; rn) marine
specimens; n) aeolian forms and processes (snowdrifts,
snowbarchans, sastrugi, wind scoops, snow deflation and
corrosion). Some supplementary and important information
are also added, including geochronological dating
(with age, method and material), ice drillings performed
(with depth), geophysical surveys (with used method), stable
isotope analyses, ice depth, snow accumulation and
ablation, Gps measurements, mean annual temperature,
wind direction and velocity. This work has been carried
out in the framework of the Italian Antarctic Research programme,
core project 2a.1: «Glaciology and Paleoclimate».
MARCO BONDESAN\ PAOLO Russo 1 & MARCO GATTI 2
Map of the relief and vertical movements
of the Po Plain
1Dipartimento di Scienze Geologiche e Paleontologiche,
Universita di Ferrara, c.so Ercole 1° d'Este 32,44100 Ferrara, Italy
2Istituto di Ingegneria, Universita di Ferrara,
via Saragat 1,44100 Ferrara, Italy