Sediment Transport Along Earth Flows: Intermittent Cascade Effect Between Kinematic Zones

We used GPS surveys, boreholes, seismic profiles and field observations to investigate the cross sectional geometry, kinematics and sediment discharge of the Mount Pizzuto earth flow in southern Italy. This earth flow is characterized by several kinematic zones, characterized by an area of stretching with normal faults upslope and an area of shortening with thrust faults downslope. Our results indicate that: (i) during surging episodes, earth flow acceleration propagate from the head toward the toe with constant sediment discharge inducing a cascade effect between consecutive kinematic zones, (ii) change in mechanical behavior of the material might occur due to the presence of a well-defined neck influencing movement propagation, (iii) during ordinary movements, sediment discharge varies along the flow and the activity of kinematic zones seems to be independent from each other. Implications are that it is not correct to consider sediment discharge as constant but rather as a function of the earth flow activity.