Subsidence 23 : The vertical fall of earth, usually caused by the loss of underground water or gas support, sometimes resulting from man-made pumping and sometimes from seismic action
Natural and Environmental Disaster Information Exchange System European Commission NEDIES, Forces of Nature: TQ 2000, Landslide Glossary, Directorate General Joint Research Centre DG JRC, Institute for the Protection and Security of the Citizen (IPSC), Varese, Italy 2012. http://library.thinkquest.org/C003603/english/land slides/glossary.shtml?tqskip1=1, (ND/ Lndsld Sci - Brit) {156}
Natural and Environmental Disaster Information Exchange System European Commission NEDIES, Forces of Nature: TQ 2000, Glossary (definitions of important terms related to forces of nature), Directorate General Joint Research Centre DG JRC, Institute for the Protection and Security of the Citizen (IPSC), Varese, Italy 2012. http://library.thinkquest.org/C003603/english/glos sary.shtml, (ND/ Gen - Brit) {154}