Humans as Geologic Agents
Homo sapiens is the only known species to consciously effect change to the Earth’s geologic environment. We reshape the Earth; intensify erosion; modify rivers; change local climates; pollute water resources, soils, and geologic media; and alter soils and the biosphere. We dig holes in it, remove parts of it, and bury highly toxic materials in it. In this volume, the authors explore human impact on the Earth and attempt to answer the following questions. What have we done to Terra? How fast have we effected change? Are the changes permanent? Are they good, or have we inadvertently caused more damage? Can we, should we, repair some or all of these changes? These are important questions for the geoscience community because, as those most knowledgeable about the Earth and its resources, geologists play a major role in sustaining and preserving the Earth.
Impacts of coal mining
Published:January 01, 2005
Coal mining probably results in a greater disturbance to the geologic conditions of an area than any other form of mining. This is due primarily to the nature of the coal deposits, which are commonly extensive, covering large areas and consisting of multiple seams extending over significant vertical intervals. Surface mining results in the disturbance of the ground surface and shallow subsurface materials over large areas. Reclamation of these mines generally results in subdued versions of the original landforms, rerouted drainage systems, and disrupted subsurface materials. Underground mines may be far more extensive, creating nearly continuous subsurface workings, which may result in postmining effects such as subsidence, mine pools, mine fires, and the accumulation of gases. Both mining types also affect surface and underground water, generally resulting in the deterioration of water quality and often capturing surface flow and changing, at least temporarily, groundwater levels. The following description concerns coal mining in the conterminous United States, although the changes in geologic conditions could be applicable in any coal mining region in the world.