A more than 23 years long and detailed geodetic record describing the kinematics of the Mandria (or Left Bank Upstream) landslide, a major deep-seated landslide close to the Polyphyton Dam, Greece, was analysed on the basis of advanced signal analysis techniques without any geotechnical constraints. It was found that all points share the same pattern of displacement which characterises both short and longer records. The overall behaviour of the landslide can be described as viscoelastic and viscous or elastoviscous, with multi-annual periodic effects superimposed on the creep, as the results of spectral analysis indicate. The landslide seems insensitive to seasonal variations of precipitation and to annual fluctuations of the reservoir level, although the first filling of the reservoir is likely to have had an important role in its movement. In lack of subsurface information, the available data indicate that the landslide corresponds to a rigid mass dominated by brittle behaviour and internal shearing, with its kinematics controlled by thin mylonitic layers along low- and high-angle faults.
- statistical analysis