Physics of Cooling Lava :: physics lava volcano

On January 23rd 1973 a newfangled venthole unexpectedly erupted in the Vestmannaeyjar archipelago, southwest of Iceland. The new venthole was a fissure 1.25 miles long and yet 1100 yards from the center of town, also named Vestmannaeyjar. The new volcano was named Heimaey. The town was mostly evacuated over the next few age and the lava slowly flowed towards town and the mouth of the harbor for the next seven months. Vestmannaeyjar is the only good harbour in that part of Iceland, and was the base for a oversize fishing fleet that produces a significant part of Icelands GNP. As the lava threatened to overrun the town and close off the harbor, a termination was made to try to slow and divert the lava by cooling it with ocean water. The idea was initially scoffed at, but when small initial efforts seemed to have an accomplishment the scale of the operation was increased. Over seven months eight million cube-shaped yards of sea water were pumped onto the lava flow they cooled 5 million third-dimensional yards of basalt lava to solid rock. The harbor and much of the town survived the bam, likely as a result of the efforts to cool the lava.Iceland is known for its volcanic activity. A few historic period before Heimaey erupted a nearby sub pelagic eruption organize the new island of Surtsey. The town of Vestmannaeyjar already had an extinct volcano on its outskirts, the volcano was known as Helgafell. It was thought to have been extinct for several one hundred years. In January 1973 a new fissure opened up a few hundred yards from the extinct volcano. It went clear across the island and into the ocean on both sides. Boats escaping the harbor saw red magma under the water, and sub oceanic power and water lines from the mainland were broken by the eruption. In the initial eruption a curtain of lava 500 feet erupted from the fissure, after a few long time the eruption was mostly from a single vent, with a cinder conoid 300 feet tall. The lava flows from the eruption were a viscous slow moving basaltic magma. Average speeds for the lava flows were 3 to 9 yards a day. These relatively slow speeds are what made it possible to try and cool and divert the lava.The lava was initially cooled with call down pumps and hoses, later in the effort large pumps were leased from the US forces and several fire fighting boats were used.