S
KS
A
N
S
We Sv
2»,
Figure 7. Isolines of the percentage of landslided area measured with grid cells of 1 sq. km (0, 1, 4, 7, 10, 20, 40,
60, 80, 10096). Location on figure 6.
-1
\J
/
/
/
7
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0.0 0 20. 99m
\
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\ AMBATO
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Figure 8. Isoseism map of the 5th March, 1987
earthquake (after Barberi et al., 1988). The degree of
intensity is indicated for each line. Black boxes
represent the two main shock epicentres with
magnitude (Msw). The smaller sinuous lines are three
isolines encircling areas of landsliding different density
(1-49%, 50-99% and 100%).
278
1) the main active faults were identified and the average
dislocation rate and sense of motions quantified where
possible;
2) landslides triggered by earthquakes were mapped and
quantified;
3) isoline shape of the area affected by landslides
coincides with the orientation of the active faults, of
isoseismes and of microseismicity, while its maximum
density is very close to the related earthquake epicentres;
4) the mountain slopes facing ESE show the highest
concentration of landslides; comparison of this
distribution with the dominant WNW active. fault dip could
be a good topic for further seismic analyses.
This study shows, in my opinion, that coregistration of
remotely-sensed, topographical and geological data is a
good procedure to assist seismic and landslide hazard.
ACKNOWLEDGMENTS
| am indebted with L. Ferrari and G. Pasquare for field
assistance and with A. Cavallin for cooperation in some
of the computer elaborations. The author benefited of a
Ph.D. grant from Ministero Italiano della Pubblica
Istruzione and from Istituto Nazionale di Geofisica -
Gruppo Nazionale per la Vulcanologia.
REFERENCES
Barberi, F., Belloni, L., Ferrari, L., Pasquare, G.,
Previtali, F., Tibaldi, A. and Zonno, G., 1988. Riesgo
Sismico. Technical Report Coca-Codo Sinclair Project,
Quito, Ecuador.
CERESIS, 1986. Catalogo de terremotos para America
del Sur. Datos de hipocentros y intensidades.
