Abstract. Landslides triggered by strong earthquakes often M] vc W
caused most of the global damage and most of all casualties B_aLqB]U
related to the events, such as shown by the M = 7.7 Peru 7%b?[}y4
earthquake in 1970, by the M = 7.6 El Salvador earthquake &k+ jVymH
in 2001 or by the M = 7.4 Khait (Tajikistan) earthquake 4w<U%57
in 1949. The obvious impact of a landslide on the population ~C\R!DN,
is directly related to its movement. Yet, prediction of "6[fqW65
future failure potential and hence future risk to population eR$qw#%c *
is necessary in order to avoid further catastrophes and involves U\*}}
the analyses of the origin of seismic instability. The ,73J #
seismic landslide potential is mainly determined by the interaction j;WZ[g#t
between the regional seismic hazard and local geological WA \
P`'lg
conditions. At a local scale, seismic factors interfering &O/; YGEAB
with geological conditions can produce site-specific ground "
;8H;U`
motions. The influence of such Site Effects on instability is DZ<q)EpC
the principal topic of this paper, which is divided into two G0Eqo$W)S
parts, A and B. The present Part A is concerned with the correlation >;-. rJFr
of field data with observed instability phenomena. 6F(;=iY8
Field data were obtained on mainly three landslide sites in 7y""#-}V[r
the Northern Tien Shan Mountains in Kyrgyzstan, Central D
C {l.a.
Asia. Geophysical prospecting, earthquake recordings, geological d %1j4JE{
observation, trenching and geotechnical tests were rF'_YYpr>
the main investigation tools. The collected information gives *I : ^g
an insight in the geological background of the slope failure vR[XbsNM
and allows us to roughly infer failure mechanisms from field 'avzESe~'
evidence. A detailed analysis of the susceptibility of a mechanism ,9SBGxK5`
to specific geological conditions will be shown in Part 2_'{f1bVxz
B. U%.OH?;f
1 Introduction
