Earthquakes cause a potential energy change in Earth's interior because they generate permanent vertical deformation in the gravitational field. The cumulative change of this potential energy in the crust, computed for the period between 1977 and 1998, shows systematic patterns in various tectonic provinces. Regions of extensional tectonics show systematic potential energy loss and regions of compressional tectonics typically show energy gain. Therefore, we claim that the crustal potential energy change can serve as a good indicator of compressional and extentional tectonics. ¿ 2000 American Geophysical Union