Viscoelastic : A type of deformation in which a material behaves like an elastic solid when it is rapidly strained on time scales of seconds to hours, but deforms viscously by plastic flow over long periods of geologic time
Natural and Environmental Disaster Information Exchange System NEDIES, European Commission, Directorate General Joint Research Centre (DG JRC), Institute for the Protection and Security of the Citizen (IPSC), Ispra (Varese) Italy, http://nedies.jrc.it/index.asp?ID=82#Top, University of Utah Seismograph Stations UUSS, Glossary of Terms, Utah, USA 2012. http://www.seis.utah.edu/qfacts/glossary.shtml, (ND/ Erthq - Amer) {166}