Scientists check out the active fumarolic fissure at the summit of Kanaga Volcano on September 22, 2015. From left to right: Helicopter N312MH, piloted by Dan Leary, ferried geologist Michelle Coombs (USGS), student Katherine Sheppard (UCSB), postdoc Mattia Pistone (Smithsonian) and geologist Liz Cottrell (taking photo, Smithsonian) from the boat to the summit. The “NSF GeoPRISMS Shared Platform R/V Maritime Maid Leg 3: Western Aleutians” facilitated the team’s expedition to 7 active volcanic islands, from Kanaga to Buldir, in search of mafic tephra. How is continental crust generated? The Western Aleutians may hold the key. Photo credit: Elizabeth Cottrell (NMNH Smithsonian Institution)