After blue flames, towering ash clouds, and gurgling fountains of lava, the fourth horseman of the volcanic apocalypse has arrived at Kilauea: Hawaii’s most active volcano has created its own weather system.
The U.S Geological Survey (USGS) reported that billowing pyrocumulus clouds are rising over Kilauea’s angry eruption at Fissure 8 in the Lower East Rift Zone on Monday.
Pyrocumulus clouds—also known as flammagenitus clouds—are most commonly caused by wildfires. They form when heat from the ground, whether from burning trees or scalding molten rock, causes the air around it to warm and rise, carrying water vapor with it. As that air reaches the cooler heights of the upper atmosphere, that water vapor condenses around tiny particles like ash to form clouds. Those clouds can become unstable and in turn cause thunderstorms.
Your average wildfires burn at 800 degrees Celsius (1,472 degrees Fahrenheit). In comparison, lava at Kilauea measures 1,170 degrees Celsius (2,140 degrees Fahrenheit) so the heat part of the pyrocumulus equation is in place.
The activity at Kilauea really picked up in the area around Fissure 8 located on the southwest edge of the East Rift Zone on Monday. According to USGS, the region saw lava “fountaining to heights of 200 feet at times and feeding a lava flow that was traveling to the northeast.” The agency also reported that wind has picked up delicate threads of volcanic glass called Pele’s hair (after the Hawaiian volcano goddess) and other bits of volcanic detritus. Together, these ingredients have helped the clouds to form and rise up to 6 kilometers (3.7 miles) into the atmosphere.
Sure, the clouds aren’t as flashy as the pyrotechnics below them. But they’re a reminder volcanoes have immense power to reshape not just the Earth but the atmosphere above it.