Geography Reference
In-Depth Information
Figure 5.1
Active volcanoes with high disaster potential chosen for intensive monitoring under the auspices of the
International Decade for Natural Disaster Reduction.
in works that use the classic geographical method
of synthesis across a wide spectrum of disciplines,
although vulcanologists (Francis 1994) are as likely
to be involved as are geographers (Chester 1993).
One aspect that distinguishes the latter's
contribution is concern for the environmental
impact of eruptions (Duncan
et al
. 1981), an interest
that is shared with the biologists who have studied
the recolonisation of volcanic landscapes by
vegetation after the cessation of volcanic activity
(Del Moral andWood 1993).
Less attention has been given by physical
geographers to seismic than to volcanic
phenomena. Nevertheless, active tectonics have
been the subject of some interesting
geomorphological studies, including a review of
morpho-tectonic process and form in China
(Doornkamp and Han 1985) and diffusion models
of fault-scarp degradation (Nash 1981). The
potential to apply geomorphological methods to
practical problems of earthquake mitigation and
seismic safety is underexploited. Little has been
accomplished in this field by geographers, although
some very interesting studies were published in the
1980s by Kenneth Hewitt (e.g. 1983), who sought
to connect spatial variations in the hazards of
ground shaking with altitudinal patterns of
settlement and ecotones. He found that piedmont
alluvial fans are especially vulnerable to earthquake
damage as they consist of unconsolidated debris that
can undergo compaction subsidence and
liquefaction failure. In addition, Cooke and
Doornkamp (1990: p. 346) argued that tectonic
geomorphologists have the potential to make a
significant contribution to earthquake prediction
studies by helping to identify places where ground
stresses are at a maximum. However, there is little
evidence that they have yet done so, although they
have contributed to seismic risk assessments
(Panizza 1989).
MAPPING AND ZONATION
Ever since the formulation of the first intensity
scales in the 1700s and 1800s, students of
