Alaska may be hiding a supervolcano.

The article reports that according to a study conducted by John Power, a geophysicist at the U.S. Geological Survey's Alaska Volcano Observatory in Anchorage, a wide crater, created when the supervolcano exploded, connects at least five existing volcanoes at Alaska's Aleutian Islands. It mentons that an analysis of volcanic gases such as sulfur dioxide, as well as patterns of microearthquakes in the area, further suggest the presence of a caldera.