Abstract. Landslides triggered by strong earthquakes often Q+W1lv8R
caused most of the global damage and most of all casualties LC'{p
related to the events, such as shown by the M = 7.7 Peru $h*L=t(
earthquake in 1970, by the M = 7.6 El Salvador earthquake MM x9(`t*.
in 2001 or by the M = 7.4 Khait (Tajikistan) earthquake 8n*.) .33
in 1949. The obvious impact of a landslide on the population PqiB\~o@Z
is directly related to its movement. Yet, prediction of +O*/"]h
future failure potential and hence future risk to population paD !Z0v&
is necessary in order to avoid further catastrophes and involves
+7=K/[9p
the analyses of the origin of seismic instability. The 7r~~Y%=C|
seismic landslide potential is mainly determined by the interaction qa0 yg8,<
between the regional seismic hazard and local geological ,#L=v]
conditions. At a local scale, seismic factors interfering $ >u*} X9
with geological conditions can produce site-specific ground 6er-{.L=
motions. The influence of such Site Effects on instability is F7O(Cy"1
the principal topic of this paper, which is divided into two FXi{87F2
parts, A and B. The present Part A is concerned with the correlation =9fajRFTt
of field data with observed instability phenomena. p IU&^yX>
Field data were obtained on mainly three landslide sites in f
(F)1
the Northern Tien Shan Mountains in Kyrgyzstan, Central .Z JRO>S
Asia. Geophysical prospecting, earthquake recordings, geological Stu4t==U
observation, trenching and geotechnical tests were k[:bQ)H
the main investigation tools. The collected information gives \uza=e
an insight in the geological background of the slope failure 2C9V|[U,
and allows us to roughly infer failure mechanisms from field t3&LO~Ye
evidence. A detailed analysis of the susceptibility of a mechanism br":y>=,
to specific geological conditions will be shown in Part fngOeLVG
B. ,Q
HU_jt
1 Introduction
