All sessions, meetings, dinners, and social events are held in the Sheraton‐Park Hotel. The floor plan on the facing page, though somewhat idealized, can be used to locate meeting places. Exhibit Hall 1 is directly below Sheraton Hall. Exhibit Hall 2 is adjacent to it, beneath the Concourse of States.Section sessions are arranged in alphabetical order according to the code symbols listed below: G, Geodesy P, Planetary Sciences GA, Geomagnetism and Aeronomy S, Seismology H, Hydrology T, Tectonophysics M, Meteorology V, Volcanology, Geochemistry, and O, Oceanography Petrolog