Wednesday, October 15, 2008
Devastation Trail, Hawaii Volcanoes National Park
When Kilauea Iki erupted from vents on Pu'u Pua'i in November of 1959, several feet of hot ash and cinder-sized pieces of pumice fell on the lush fern forest downwind. Devastation trail follows the edge of this inundation, linking the Kilauea Iki Overlook Parking lot with another parking lot at the intersection of Crater Rim Drive with Chain of Craters Road in a wonderful and interesting 0.7 mile, 30 to 45 minute) hike.
During the eruption, fire fountains of molten lava shot up as high as 1900 feet tall from the eruptive rifts. For a sense of scale, the worlds tallest building, the Taipei 101 which is 101 stories tall and 1667 feet high, would be dwarfed by these fire fountains. These immense fountains spread ash, pumice and spatter all around the area, as well as fed liquid lava to the lava pond within Kilauea Iki crater. The spatter was hot and plastic enough to weld together into the spatter cones you see on Pu'u Pua'i, however, the tephra and ash pumice spread out and fell downwind, depositing an immensely thick (as much as 3 meters) blanket when the eruption column collapsed between fountains. This pumice buried lush forest, which is preserved on the eastern side of Devastation Trail. On the west side of the trail is the sterile, moon-like devastation surface of pumice. A few ohia trees, dead and bleached, poke up through the pumice and very gradually some ohia, ohelo and ferns are beginning to recolonize the dead zone. Look for numerous tree molds along the trail in the section about a third of the way from Pu'u Pua'i to the Devastation Trail parking lot.
Pumice results when there is a lot of gas and water dissolved in the liquid lava. As the lava is erupted, pressure is released, the melt begins to cool quickly and the gas is rapidly exolved from the liquid lava—much the way carbon dioxide is exolved as a bubbly froth when you shake a can of soda pop. The spatter and lava in the ponds cool slowly enough for all the gas to escape, and the resultant rock is very dense when it finally solidifies. The pumice, however, chills so rapidly it forms a glass-like, frothy substance because it traps the bubbles. This is why pumice has a low enough density to float on water.
Written and produced by Donald MacGowan. Narrated by Frank Burgess. Videography by Donnie MacGowan and Frank Burgess; original musical score by Donnie MacGowan.
For more information on touring Hawai'i in general and visiting the Big Island in particular, go to www.tourguidehawaii.com and www.lovingthebigisland.wordpress.com.
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