ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

- a detailed geomorphological map with special regard to
type and age of landslides, and, in addition, a multi-temporal
interpretation of aerial photographs,
- geophysical and dendrogeomorphological investigations
to reconstruct activity phases in the past,
- precipitation events and the special hydrology of slopes
as the main triggering factors, and
- as much as available, data about groundprices in settlement
areas threatened by mass movements.
All information will be stored in a data base.
Parallel to this project, a susceptibility map with the scale
of 1:10 000 for the Katzenloch valley and the Melb valley,
which are both highly affected by landslides, has been produced.
Digital factor maps showing geology, relief forms
(slope angle, compiled from a Deu), landslide distribution,
hydrology (wells, bogs) and infrastructure (e.g. buildings,
roads) were stored in a Geographic Information System.
Analyses of the relative frequency of landslides in each
geological formation and slope angle category (ino) generate
weighting factors for a simple evaluation scheme to determine
susceptibility classes (high, moderate, low). These
are further modified according to the influences of hydrology
and infrastructure.
The product, a well-structured computer-based landslide
susceptibility map delineates potential landslide areas
and is to be considered a useful tool for effective landuse
planning.
VALERY N. GUBIN
Tectonic processes and relief's evolution
of areas of ancient ice sheets
Byelorussian Geological Prospecting Research Institute
Staroborisovsky tract 14, 220114 Minsk, Belarus
The pleistocene morphogenisis stage at the west of the Eastern-European
platform (Eep) was distinguished by high
activity of tectonic processes. The earth crust structural
forms as well as the rotational geodynamics elements had
affected significantly the glacial covers dynamics and topography
evolution. The crystal basement's high elevation
(from +50 to -500 m) played a dominant role in thick moraine
layers accumulation as well as in the main rnacroforms
of Byelorussian Grjada formation. The glacial's
load increased the basement's blocks differention in case
of unsufficient thickness of the platform cover. As a result
the intensive anthropogenic base surface separation took
place.
Regional fractures (Vyzhevsko-Minsky, Oshmyansky) affected
on spatial distribution of flanking morainal topography
forms. The activation of linear structures occured
in pleistocene had led to cracks in glacier's masses, especially
in glacial cover periphery. The complicated dynamic
glacier masses structure was formed at such conditions,
which determinated the end moraine topography forms distribution.
Neotectonic structures such as blocks and rings which were
subjected to positive motion with the amplitude to 80m.
were the glacial subdividing zones of different size. The
earth crust blocks played the dividing role at Disnenskaya,
Polotskaya and Vitebskaya glacial blades at the EEP west.
Local ring structures of tectonic genesis type were arranged
to the frontiers of frontal glaciar complexes.
MAURO GUGLIELMIN
Methods of permafrost analysis in ice-free areas
of the Northern Victoria Land (Antarctica)
Servizio Geologico, Regione Lombardia,
via F. Filzi, 22 20124 Milano, Italy
In 1994 a new research project about permafrost, ground
ice analysis and periglacial geomorphology of Northern
Victoria Land (Antarctica) has been started.
This project has as principal purposes the study of permafrost
areas to identify the different types of ground ice and
to understand their relationships and to analyse the thermal
evolution of these areas.
In some ice free areas of Northern Victoria Land, near
Terra Nova Bay station, on the basis of previous geomorphological
researches (Baroni & Orombelli, 1987;
Chinn & alii, 1989; Meneghel & alii, 1994), some
landforms such as rock glaciers, raised beaches with patterned
ground and debris-covered glaciers were investigated
with the method of electrical prospection. Moreover,
in correspondence of areas investigated with geophysical
methods, some trenches were dug and some boreholes were
drilled to sample permafrost and ground ice.
A good method to identify different types of ground ice
(Selman & alii, 1988; Fournier & alii, 1990; Guglielmin &
alii, 1997) has been revealed the electrical prospection, in
particular, the method of vertical electrical soundings
(Ves); while, to recognize the buried structures and the relationship
among different types of ground ice, was better
the method of resistivity profiles.
The samples collected in the trenches and boreholes are
now analysing and will be useful to calibrate the geoelectric
method and to identify the different conditions of formation
of the ground ice.
The boreholes drilled have been used to measure the thermal
profile and also to install an automatic station to record
the variations of the temperature at different depth.
This station measures also the air temperature and the global
incident radiation and will let to study the relationships
between climate and thermal regime of active layer and
permafrost. From geoelectric prospecting performed is
possible to recognize 5 different types of ground ice:
1. saline permafrost with an electrical resistivity ranging
from 50 to 1,300 Wm;
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