The RIDGE Initiative provide support for theoretical integration of field and laboratory studies of ridge.crest processes. To provide a strong natural focus to attract highly capable thoreticians from within the broader geological /biolobical community, a second annual RIDGE Theoretical Insttitute will be conveined. The purpose of the Institute is to provide an environment for progress on critical theoretical RIDGE problems that require an interdisciplinary approach with two specific goals: to give researchers and their students the required background to address complex interdisciplinary problems, and to foster stron linkages among theoretical developments on a particular ridge.crest problem. This Institute will focus on magmatic on magmatic and hydrothermal systems, and will consist of a short course of lectures, discussions, and poster sessions, to be followed by a workshop that will provide a forum for intensive scientific interaction among participants.