Eli Silver, UC Santa Cruz, Earth and Planetary Sciences
Dr. Eli Silver of UC Santa Cruz will outline some of the latest research on plate tectonics. Presently, continental crust is being created in subduction zone settings (sites where tectonic plates converge) such as the Aleutians and Sumatra, due to both magmatic addition to the crust and to tectonic off-scraping. Other subduction zones (Central America, Tonga, Mariana, Peru, northern Chile, northern Japan, Kuriles) are undergoing crustal destruction through the process of subduction erosion. Global estimates indicate thmagmatic addition plus sediment accretion slightly exceeds the combined rates of subductionat erosion and sediment subduction, leaving the Earth slightly positive in terms of the growth of continental crust.