Abstract. Landslides triggered by strong earthquakes often bBf+z7iyc
caused most of the global damage and most of all casualties 6 s/O\A
related to the events, such as shown by the M = 7.7 Peru 8,Z0J
earthquake in 1970, by the M = 7.6 El Salvador earthquake m[XN,IE#u
in 2001 or by the M = 7.4 Khait (Tajikistan) earthquake a &j?"o
in 1949. The obvious impact of a landslide on the population q ]aRJ`9f
is directly related to its movement. Yet, prediction of 6lGL.m'Ra
future failure potential and hence future risk to population iJK 9 -k~
is necessary in order to avoid further catastrophes and involves xHmc8G$zu
the analyses of the origin of seismic instability. The _nt% & f
seismic landslide potential is mainly determined by the interaction r_",E=e
between the regional seismic hazard and local geological ),_bDI L+
conditions. At a local scale, seismic factors interfering @QofsWC
with geological conditions can produce site-specific ground aap:~F{]X
motions. The influence of such Site Effects on instability is ) )N c|`
the principal topic of this paper, which is divided into two ~tWBCq 6
parts, A and B. The present Part A is concerned with the correlation , /pE*Yk
of field data with observed instability phenomena. 0qv)'[O
Field data were obtained on mainly three landslide sites in /\.kH6 2
the Northern Tien Shan Mountains in Kyrgyzstan, Central r]yq
#T`z
Asia. Geophysical prospecting, earthquake recordings, geological &*}S 0
observation, trenching and geotechnical tests were D'X'h}+2
the main investigation tools. The collected information gives N\u-8nE5
an insight in the geological background of the slope failure S'WmPv
and allows us to roughly infer failure mechanisms from field 9/{g%40B^
evidence. A detailed analysis of the susceptibility of a mechanism F-nt7l
to specific geological conditions will be shown in Part 4xlsdq8`t
B. _R ]1J0
1 Introduction
