Deformation of the lithosphere by tectonic forces is investigated from both observational and theoretical standpoints. Global and regional geophysical data bases, coupled with the means for their rapid display and analysis, facilitate recognition of areas of the con- tinents and oceans where the response of the lithosphere to these deforming processes might fruitfully be studied._x000D_
Gravity anomalies, from Seasat altimeter data and from land and shipboard measurements, provide critical infor- mation on the isostatic state of deformed lithosphere and therefore on its thermal and mechanical properties.