Syntectonic unconformities demonstrate simultaneous subsidence and tectonic activity. Where the lithosphere moves downward (tectonic subsidence), a basin forms and sediments are deposited. Subsequent periods of subsidence and submergence deposited clays and flints. In addition to subsidence, large earthquakes can also cause tsunamis. Continental rifting, with associated subsidence, tends to produce such landlocked water bodies. Uplift of surrounding mountain ranges and subsidence of the valley floor are both occurring. This broader definition encompasses the overall concept of soil compaction, subsidence, and heave. All volcanic seamounts follow a particular pattern of growth, activity, subsidence and eventual extinction. Unfortunately, much of the subsidence from groundwater extraction is permanent (elastic rebound is small). In a process called soil subsidence, oxidation of peat causes loss of volume. This feature has contributed to the effects of subsidence caused by extensive ground water pumping. However, calderas can also form by non-explosive means such as gradual magma subsidence. At the same time the drained soil consolidates and peat decomposes leading to land subsidence. The control of uplift and subsidence is, however, clear. The soil is soft and is prone to subsidence.