ABSTRACTS / RESUMES - Comitato Glaciologico Italiano

JOSE LUIS PALACIO-PRIETO
& ]OSEFINA HERNANDEZ-LoZANO
Hurricane Roxanne's effects on the
coastal geomorphology in southeastern Mexico
Instituto de Geografia, Universidad Nacional Aut6noma de Mexico,
Cd. Universitaria, 04510, D.F. Mexico
Hurricanes are responsible of important geomorphological
changes along coastlines. For the southeastern gulf coast of
Mexico, the frequent strike of hurricanes is reported to have
a major influence on the configuration of the shoreline,
where marine transgresions score locally hundreds of meters.
This paper is focused on the geomorphological effects
of the Hurricane Roxanne (October 8-19, 1995) along the
shoreline of the State of Campeche, southeastern Gulf coast
of Mexico. The area corresponds to the contact of the
Yucatan limestone platform and the deltaic sedimentary
deposits of major mexican rivers draining to the Gulf of
Mexico. Special enfasis is given to the interpretation of
erosion-accumulation features and damage detection on
road infrastructure, closely related to the geomorphological
evolution of the coastal area.
The use of alternative remote-sensing tools based on a color
video remote sensing system for a rapid assessment is
also stressed. An aerial survey of the coast of the State of
Campeche, Mexico, was carried out after the strike of hurricane
Roxanne. Two video cameras were used to survey
the damages to infrastructure and detection of morphological
features along the coast. Video images were digitized
and enhanced using multi-media software and finally integrated
and interpreted in the context of a geographical
information system.
The surveyed coast may be divided in two: a) an erosive
one corresponding to the northern part and b) an accummulative
to the south and west. Main damages were detected
where the roads run close to the shore (up to 150 m
far from the coastline) and in those places where ancient
channels obturated with recent sedimentation events are
present.
VALENTINA P. P ALIJENKO
The geomorphologic diagnosis of neotectonicaIIy
active faults
Department of Geomorphology, Institute of Geography
of National Academy of Science of Ukraine,
Volodymirska str., 44, 252034, Kyiv, Ukraine
The diagnostics of neotectonical activation along the faults
is one of the actual geodynamical problems. In cases of
closed platform structures which are often characterized
with absence of direct indication of movements along
faults, of weak differentiability in space of neotectonic activity
and mainly long periodical activation, the geomorphologic
diagnosis is the mostly effective method. To substantiate
the global and regional neogeodynamic models which
accounts the spatial differentiation of stress fields, various
kinematics and activity of structures we had distinguished
the regularities of disposition and interaction of neotectonically
active faults. The geomorphologic diagnostics of
neotectonic activation are performed in the some following
stages:
1. the exposition of dominant geomorphologic indicators
of activity and their paragenetic complexes,
2. zoning of territory on informatively degrees and reliability
levels of various indicator or their combination,
3. the exposition of spatial regularities of neotectonical activation
along faults, determination of zones of their interaction
and mutual influence,
4. quantitative parametrization of faults with data of total
amplitudes and gradients of vertical and horizontal movements
velocities involved for active zone classification.
As a result of step by step analysis of latest and modern
tectonic activation it is performed zoning of Ukrainian territory
with an account of their differences, which are observed
in kinematics, dynamics, in history of development
and with account of moment of the last activation along
faults which is registered by geomorphologic indicators.
Geomorphologic indicators of shear, extentional, up-and
downthrown fault of tear deformations are distinguished.
The special attention is put to approbation of geomorphodynamical
approach to diagnosis of horizontal movement
along closed faults in the limits of plain-platform morphostructures.
It is established that in ranges of Late Oligocenic,
Late Oligocenic-Middle Pliocenic, Middle Pliocenic­
Anthropogenic and modern stages of morphogenesis the
geomorphological indicators are differ substantially. The
events of maximal activation of reliefmaking deformations
of earthcrust along fault with compression paroxysm in
Late Eocene, Late Oligocene, Middle and Late Miocene,
on Pliocene-antropogenic interface which are typical for
the alpine-Asiatic orogenic belt and for adjacent intracontinental
plain-platform morphostructures. In the modern
stage fault raptures develop in pulse (with frequent seismic
events), creep and pulse-creep regime.
As a whole the time-spatial discrete activation of deformation
along faults as well as informative multicipherence of
geomorphologic indicators are inherent to neotectonic and
modern stages. The quantitative parameters of fault dynamics
in different time intervals and zones of dynamic influence
of deep seated faults are determined on the basis
of large scaled field researches.
Knowledge about neotectonical and modern activation
along faults were used for seismic zoning of Ukraine, for
distinguishing of geomorphodynamical and actuotectonical
risque zones, for substantiating of potentially ecodefective
technical structures, of toxic material depositories etc.
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