Subsidence (noun, “sub-SY-dens”)
Subsidence happens when land sinks because water, soil, rock or other underground materials are removed. It can happen quickly, with the sudden appearance of a sinkhole or abrupt shift during an earthquake. It can also happen gradually as people remove groundwater from aquifers. Over time, the overlying land sinks down to fill the open space.
Most subsidence occurs in areas where people pump groundwater out of aquifers. These natural storage areas are not underground lakes. Rather, they are porous rocks that hold water like vast sponges. Water...
English (US)