Setting out on the Cruise (IMAGE) Washington University in St. Louis Caption This is the Thomas G. Thompson and the Marcus G. Langseth at the Navy Pier in Guam. The Thompson laid seismic instruments, which are stacked and ready on its deck, and the Langseth then sailed transects over the instrumented area, firing its airgun array and recording the reflections from subsurface rock layers. Credit Doug Wiens Usage Restrictions please credit 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.