9314542 Von Herzen This award will support a collaborative study by Woods Hole and MIT scientists of hydrothermal circulation at the TAG area on the Mid- Atlantic Ridge. Instrumentation and sampling will be done at TAG prior to Ocean Drilling Program drilling into the hydrothermal system. Water column instrumentation will be used to measure the change in total heat output from the system, while chemical measurements on venting fluids will provide additional constraints on changes in subsurface flow. This work being done in collaboration with Japanese scientists who will provide the submersible for the initial work. Work in the area subsequent to drilling will be from the Alvin. ***
