Abstract. Landslides triggered by strong earthquakes often BS#@ehdig
caused most of the global damage and most of all casualties h30~2]h H
related to the events, such as shown by the M = 7.7 Peru ET`;TfqM
earthquake in 1970, by the M = 7.6 El Salvador earthquake |:tFQ.Z'2
in 2001 or by the M = 7.4 Khait (Tajikistan) earthquake fD<3Tl8U0
in 1949. The obvious impact of a landslide on the population :R<n{%~
is directly related to its movement. Yet, prediction of (6G5UwSt
future failure potential and hence future risk to population %fpc H
is necessary in order to avoid further catastrophes and involves -_ [Z 5%B
the analyses of the origin of seismic instability. The ~J6c1jG
seismic landslide potential is mainly determined by the interaction #$Z|)i]w
between the regional seismic hazard and local geological dt
4_x1
conditions. At a local scale, seismic factors interfering O(otI-Lc
with geological conditions can produce site-specific ground HzT"{N9
motions. The influence of such Site Effects on instability is ?K/z`E!xhN
the principal topic of this paper, which is divided into two J~:/,'Ea
parts, A and B. The present Part A is concerned with the correlation ht S5<+Y
of field data with observed instability phenomena. mYN|)QVKy
Field data were obtained on mainly three landslide sites in m(8t |~S
the Northern Tien Shan Mountains in Kyrgyzstan, Central &Fl^&&1C
Asia. Geophysical prospecting, earthquake recordings, geological $N=A, S
observation, trenching and geotechnical tests were A|Yq Bl
the main investigation tools. The collected information gives D g@>d0FW
an insight in the geological background of the slope failure _Ucj)Ud k
and allows us to roughly infer failure mechanisms from field y@G5I > v
evidence. A detailed analysis of the susceptibility of a mechanism !_cT_
WHty
to specific geological conditions will be shown in Part ,bCPO` 45
B. ge[+/$(1
1 Introduction
