Showing posts with label Krakatoa. Show all posts
Showing posts with label Krakatoa. Show all posts

Sunday, February 8, 2009

Thar she blows!


My body's burnin' like a lava from a Mauna Loa
My heart's crackin' like a Krakatoa

~~The B-52's "Lava"

Mount Redoubt in Alaska is showing signs of imminent eruption, and I hope that everyone will get to safety before it blows.

It's made me think about another volcano, and yes, it's another of my bizarre fascinations: Krakatoa.

Krakatoa (Krakatau in Indonesian) is an Indonesian island between Java and Sumatra. (Click on picture to see it larger.) On August 26-27, 1883, a volcanic explosion occurred, and it is one of the most violent in modern history.

A few months before the eruption, earthquake activity was frequent and intense, and felt as far away as Australia. Steam venting occurred from the island's volcanic cones, and ash eruptions reached 20,000 feet (6 km). After a period of relative quiet, the volcano started to erupt again in July, and the eruption was so violent that the tides in the area became unusually high. On August 24, eruptions became more intense, and at about 1 pm on August 26, the volcano began its final self-destruction. By 2 pm, the ash cloud rose 17 miles (27 km) above the island. The eruption was almost continuous and explosions were heard every ten minutes. Ships within 15 miles or so experienced ash fall, with some pieces of hot pumice up to 10 cm in diameter falling on deck.

On August 27, four huge explosions took place, each accompanied by gigantic tsunamis, which are believed to have been over 100 feet (30 m) high in places. Ash was propelled to a height of 50 miles (80 km). The sound of the explosion was the loudest historically reported, reaching 180 decibels 100 miles (160 km) away, and distinctly heard as far away as Perth in Australia, about 2,200 miles (3,500 km) away, and the island of Rodrigues near Mauritius, about 3,000 miles (4,800 km) away. The explosion was the equivalent of 200 megatons of TNT, about 13,000 times the force of the bomb that was dropped on Hiroshima.

On August 28, Krakatoa was silent.

It was also considerably diminished. About 2/3 of the island's territory vanished in the eruption, believed now to have sunk into an empty magma chamber. The official death toll was 36,417, most of those due to the tsunamis, but some sources believe that an estimated 120,000 or more perished. Researchers were unable to reach the island until May 1884, and the only living thing they found was a spider in a crevice. The massive cloud of ash affected global weather, dropping the average temperature worldwide by 34 degrees Fahrenheit (1.2 Celsius). Weather patterns remained erratic for years, and temperatures finally returned to normal in 1888. Amazing sunsets were seen worldwide for months, and current speculation posits that the red sky in Edvard Munch's 1893 painting "The Scream" was his interpretation of one of these sunsets.

Eruptions at the volcano since 1927 have resulted in a new island in the same location, called Anak Krakatau, which means child of Krakatoa. The volcano is still active, and since the 1950s, the island has grown an average of five inches (13 cm) per week. The volcano started erupting again in late 2007, and scientists monitoring the activity have warned people to stay out of a 3 km (approx. 1.9 mile) zone around the island. The island is now a nature preserve, and is the source of biologic research of an ecosystem resulting after an environment has been sterilized.

It fascinates me because it shows the awesome--and I mean that in the truest sense of the word--power of nature.

"Krakatau." Wikipedia. Wikipedia, 2008. Answers.com 08 Feb. 2009. http://www.answers.com/topic/krakatoa