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Volcanoes » Pyroclastic Flow at Shiveluch Volcano
Pyroclastic Flow at Shiveluch Volcano
Satellite images of one of the most active volcanoes on the Kamchatka Peninsula of Russia
Republished from January and February, 2011 press releases by NASA's Earth Observatory xxx University.
| The false-color satellite image on the above left is from the Advanced Spaceborne Thermal Emission and Reflection Radiometer
(ASTER) on the Terra satellite shows the remnants of a large pyroclastic flow on the slopes of Shiveluch Volcano. The image on the right was acquired after ASTER detected heat from the flow during or shortly after the event on January 25, 2011.
Note how the heat signatures from January line up with the dark surface deposits visible on February 25; those deposits cover
more than 10 square kilometers (4 square miles). |
The Pyroclastic Flow Hazard
Pyroclastic flows are some of the most fearsome hazards posed by erupting volcanoes. These avalanches of superheated
ash, gas, and rock are responsible for some of the most famous volcanic disasters in history, including the burial
of the ancient Roman city of Pompei and the destruction of Saint-Pierre in 1902. More recently, pyroclastic flows
from Mount Merapi in Indonesia caused most of the casualties during the volcano's 2010 eruption.
The intense heat-over 1,000° Celsius (1800° Fahrenheit)-the terrific speed-up to 720 kilometers (450 miles) per hour-and
the mixture of toxic gases all contribute to the deadly potential. Pyroclastic flows can incinerate, burn, or asphyxiate
people who cannot get out of the flow path.
False-Color Image of Shiveluch Pyroclastic Flow
The false-color satellite image on the above left is from the Advanced Spaceborne Thermal Emission and Reflection Radiometer
(ASTER) on the Terra satellite shows the remnants of a large pyroclastic flow on the slopes of Shiveluch Volcano. Fortunately,
no one was hurt during the eruption and flow in the sparsely-populated area. This image was acquired on February 5, 2011.
Heat Signature of the Pyroclastic Flow
The image on the right was acquired after ASTER detected heat from the flow during or shortly after the event on January 25, 2011.
Note how the heat signatures from January line up with the dark surface deposits visible on February 25; those deposits cover
more than 10 square kilometers (4 square miles). Light brown ash covers the snow above the flow deposits, and a tiny plume
rises from Shiveluch's growing lava dome. Vegetation surrounding the volcano is colored dark red.
Dome Collapse Origin
This January image shows the flow's heat signature as measured in thermal infrared light. The white area at the lava dome is very
hot, while the red areas on the edge of the flow are just warmer than the surrounding snow. The hot trail of material descending to
the south forms a large distributed deposit, indicating a recent collapse of the lava dome
and formation of a large debris avalanche.
Shiveluch Eruptive History
With a summit that reaches 3,283 meters (10,771 feet), Shiveluch is one of the largest and most active volcanoes in Russia's
Kamchatka Peninsula. At least 60 large eruptions of Shiveluch have occurred during the past 10,000 years, making it the most
vigorous volcano of the Kuril-Kamchatka volcanic arc. According to the Global Volcanism Program, Shiveluch's current eruptive period began in 1999.
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