What Does a Volcano Look Like?

December 04, 2020


Photographer: Gabrielle Tepp
Summary Author: Gabrielle Tepp

What does a volcano look like? While you might expect a mountain with a large crater at the peak, that’s not always the case. This picture (two images combined into a panorama for a wider view) shows the summit of Bogoslof volcano in the central Aleutian Islands of Alaska. Most of the volcano is hidden beneath the Bering Sea (visible on right) with only the very top forming the small Bogoslof Island.

The 2016-2017 eruption of the volcano drastically changed the landscape and morphology of the island, which increased in area from less than 74 acres (0.3 sq km) to nearly 321 acres (1.5 sq km). Near the center of the image is a lava dome produced during the eruption that is now the highest point of the island.

The lava dome is mostly covered by pyroclastic deposits from the 70 or so explosions that occurred over 8 months. It was still steaming a year after the eruption ended when this photo was taken on August 16, 2018. The ground in front of the lava dome was covered by seawater during much of the eruption and may have been an explosion-producing vent. The oranges and yellows are hydrothermally-altered rocks. Bogoslof Island is not only an active volcano but an important breeding ground for tens of thousands of fur seals and sea birds.