Land and seabed deformation

Abstract

The development of techniques to monitor undersea and ground surface deformation and sea level changes will be highlighted at a session of invited geodesy papers at the AGU Fall Meeting, to be held in San Francisco, Calif., December 3–7 , 1984.The oceans conceal the earth's largest sudden deformation events. Subduction earthquakes at great plate boundaries produce 10–20‐m motions of the crust near offshore trenches. Inflation of undersea volcanoes and the spreading of midocean rifts also produce large changes that may go unnoticed. The great tsunami‐generating earthquakes may be associated with unusually large vertical movements of the seabed; these earthquakes also may cause vast undersea landslides. Technologies to predict these large movements have potential for improving earthquake prediction, tsunami warning, and prediction of volcanic eruptions. Fred Speiss, chief editor of a recent National Academy of Sciences book on undersea deformation, will chair this session.