Map of the Aleutian Arc in Alaska and the Andreanof study area. The lower map shows where ocean-bottom seismometers and land seismic stations recorded sound waves from an active-source seismic experiment conducted aboard the R/V Marcus G. Langseth , allowing the authors to image the deep structure of the arc crust beneath several Aleutian volcanoes. The black lines show the Langseth ship track and the yellow line shows the location of the crustal velocity profile. Credit: Mark et al. [2026] , Fi