Augustine Volcano, Alaska, USA
Photo by Richard Waitt, U.S. Geological Survey, 1988 (fair use policy)
Augustine is a young, active volcano in Alaska's Cook Inlet, where it poses a hazard to the city of Anchorage and the busy trans-Pacific air traffic around it. The Alaska Volcano Observatory has a special page reporting Augustine's current activity.
This photo shows rough, hummocky ground on West Island that got there when the side of the volcano collapsed about 350 years ago. Another lobe of volcanic waste, running northward, dates from 1883, and seafloor mapping has uncovered many more on all sides of the mountain. This sloppy behavior, in the middle of a major shipping corridor, makes Augustine exceptionally dangerous. You can see that the peak has built itself back up to a symmetrical shape already, which is pretty fast.
If it were on land, like dozens of other volcanoes in the Aleutian chain, probably nobody would worry about it much. But each huge landslide coming off its flanks raises a tsunami upon reaching the sea, and these great waves raise hell all over south-central Alaska.
The Alaskan volcanoes are arc volcanoes, related to subduction of the Pacific lithospheric plate.