Karymsky Volcano has been erupting steadily—at least on a geologic timescale—for about 500 years. This false-color satellite image captures small explosive eruptions of ash and steam, typical activity at the volcano. A white, steam-rich plume rises above the volcano, while isolated puffs of the plume drift east-southeast. Dark ash covers white snow on the volcano’s slopes and extends across the terrain to the southeast. The image was acquired by the Advanced Reflection and Emission Radiometer (ASTER) aboard the Terra satellite on January 31, 2011.
The image is remarkably similar to one taken just over a year earlier, on January 28, 2010. The likeness helps illustrate the nature of many volcanic eruptions (and many geological processes): periods of steady activity, occasionally separated by lulls, punctuated by rare catastrophic events. During Karymsky’s current eruptive cycle explosive and quiet phases have each lasted on the order of decades.
Over longer timescales, similar patterns repeat. A past eruptive cycle at Karymsky occurred from 6,100–2,800 years before present, itself divided into two main periods of activity. During the eruptive phases lava, ash, and volcanic debris built modern Karymsky. Between phases the volcanic material broke down, forming layers of soil. Even earlier (roughly 7,700 years before present) a catastrophic eruption created the caldera that now surrounds modern Karymsky. Based on this record of activity, scientists predict Karymsky will continue to erupt for another few hundred years, then fall silent for several thousand years, before a new cycle begins.
NASA Earth Observatory image by Jesse Allen and Robert Simmon, using data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Caption by Robert Simmon.