When it comes to satellite images of volcanic eruptions, the highest-resolution views often seem the most impressive. But this low-resolution image of the Earth from a Japanese weather satellite (Multi-functional Transport Satellite, or MTSAT) in orbit 35,800 kilometers above the equator provides a uniquely dramatic view of the explosive eruption of Alaska’s Mt. Redoubt Volcano on March 26, 2009.
The images were captured from a southwest vantage point (the sensor was looking northeast). At 9:13 a.m., the sky was quiet except for clouds, but at 9:30, a black column soars into the air. According to reports from the Alaska Volcano Observatory, the ash cloud reached 65,000 feet (19.8 kilometers) above sea level, shooting well past the boundary between the troposphere and the stratosphere, which that morning was located at about 9 kilometers. Volcanic particles that reach the stratosphere can linger there for months because there is no rain to wash them out of the sky.