The 10-km wide caldera on Alaska's Unmak Island formed during the 43 BCE Okmok II eruption. This massive eruption caused among the most extreme Northern Hemisphere weather conditions of the past 2,500 years that coincided with the fall of the Roman Republic.
The 10-km wide caldera on Alaska's Unmak Island formed during the 43 BCE Okmok II eruption. This massive eruption caused among the most extreme Northern Hemisphere weather conditions of the past 2,500 years that coincided with the fall of the Roman Republic. Bildrechte: Kerry Key (Columbia University, New York, NY)