Okmok Volcano (IMAGE) Geological Society of America Caption This is Figure 1 from Unema et al., including the location of Okmok volcano on Umnak Island in central Aleutian Islands. Credit J.A. Unema and GSA Bulletin Usage Restrictions Credit J.A. Unema and GSA Bulletin License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.