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Lava exploding ice
![[ Magnús Tumi Guðmundsson, U of Iceland] A volcano explodes an Iceland glacier](2002-08-30-iceland-volcano.jpg) Q: How hot is lava? Can lava be stored? What happens when lava hits ice? --Australia
A: Lava pours onto the Earth's surface at temperatures from about 700° to 1,200° Celsius (1,300° to 2,200°
Fahrenheit). That's almost as hot as molten iron (1535° C) or glass (1300° to 1500° C).
[ Magnús Tumi Guðmundsson, U of Iceland] A volcano explodes an Iceland glacier
Certainly, molten lava can be stored--the same way as molten glass or steel. To keep the rock molten, store it
in a glass or steel furnace: small quantities, of course, not a lava river.
When lava hits ice, lava melts ice: catastrophically. On Nov. 13, 1985, the Nevado del Ruiz, a snow-covered volcano high in the Andes
Mountains, exploded and threw lava and hot rocks into the snow. Ten percent of the volcano's ice cover melted like an ice cream cone in
fire.
The witches brew of water, ice, pumice, and other debris hurtled down the volcano into rivers, sweeping all before it at speeds of 40 miles
(60 kilometers) per hour. Its roar drowned shouts among villagers. Within four hours, the flows (lahars) caused by melting snow and ice
alone had killed 23,000 people, injured many, and destroyed 5,000 homes.
On Oct. 2, 1996, an Iceland volcano exploded beneath 2500 feet (760 meters) of ice. Lava flowed beneath a gigantic glacier (three-quarters the size of the Big Island of Hawaii). The orange-hot rock melted the blue-white ice, forming a huge depressed bowl on the
glacier surface. Icelanders, savvy from explosions every five years, knew she was about to blow. The pent up steam blasted the encasing
ice in a rhythmic series of outbursts that threw black ash over 1500 feet (460 meters) into the sky. The plume reached an altitude of
13,000 feet (4,000 meters).
Ten million years ago--recent geological times--Mars may have experienced such volcanic explosions below its ice surface. The
eruptions probably melted the ice and rivers of water flowed. The Martian volcanic cones show striking similarity to those found in
Iceland and are the best evidence yet of liquid water on Mars--maybe even now.
(Answered Aug. 30, 2002)
Further Surfing:
USGS: Deadly lahars from Nevado del Ruiz
U of Iceland: Chronology of Vatnajöökull eruption
USGS: Iceland's subglacial eruption
USGS: Devastation caused by lava melting snow on Mount St. Helens
Space.com: New signs of recent water at Mars
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