In December 2015, Nicaragua’s Momotombo volcano erupted for the first time in more than a century. In three months since then, more than 80 explosions have lofted gas and ash plumes into the air and have occasionally deposited hot lava onto the volcano’s flanks.
When the image was acquired, a plume was drifting west-southwest from the volcano over the town of Puerto Momotombo, the World Heritage site León Viejo, and nearby farming villages. The lava visible on the north and northeast of the summit is a combination of new and old flows.
“The lava flow extending down and off the northeast flank is still steaming,” said Chuck Connor, a geologist at University of South Florida who was conducting field research at the volcano when the eruption started. “This lava flow is light gray compared to the older, 1905 lava flows that had much greater volume.”
Connor’s team is using radar to map the new lava flow and changes in the volcano’s shape due to intrusion of new magma into the cone-shaped structure. “The volcano is located in one of the most volcanically and seismically active areas on Earth,” Connor said. The structure of the lava flows and other deposits “provide invaluable information about how such features formed on other planets like Mars.”
Indeed, while this is Momotombo’s first eruption since the early 1900s, the region is alive with activity. Momotombo rises from the middle of a chain of 19 active volcanoes that run northwest to southeast in western Nicaragua.
Geothermal power plants have cropped up in the area to take advantage of the vast amount of heat stored below the surface. One such plant is visible near Momotombo’s south side. Located close to the base of the volcano, Connor notes that the plant is “in danger from pyroclastic flows associated with explosive activity.”
NASA Earth Observatory image by Jesse Allen, using data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Caption by Kathryn Hansen.
In early September 2007, Tanzaniarsquo;s Ol Doinyo Lengai Volcano erupted, sending a cloud of ash into the atmosphere. The volcanic plume appears pale blue-gray, distinct near the summit, and growing more diffuse to the south. The charcoal-colored stains on the volcano’s flanks appear to be lava, but they are actually burn scars left behind by fires that were spawned by fast-flowing, narrow rivers of lava ejected by the volcano.