Geosphere Journal Entry

Geosphere Journal Entry

Lava Keeps Gushing at Kilauea (May 10, 2010)

Lava keeps gushing from Hawaii's Kilauea volcano. Most of the lava disappears into underground lava tubes but fresh lava flows are visible on the surface as well. Some of the lava is flowing all the way to the sea. Sulfur dioxide levels have been up to four times higher than normal at the volcano's summit. The foul-smelling sulfur combines with oxygen and water vapor to form toxic volcanic smog or "vog" that kills crops and triggers breathing problems.

Kilauea features two different kinds of lava. Most of the lava starts out as pahoehoe, a type with a smooth, ropy texture. Pahoehoe can change into 'a'a lava as it cools. 'A'a has a rough, rubbly texture made up of blocks of broken lava.

Vulcanologists say Kilauea first erupted between 300,000 and 600,000 years ago. Its eruptions have deposited layer after layer of lava that give the volcano its shield-like shape. Although most of its eruptions are gentle, it sometimes bursts with more violent explosions. An eruption in 1790 killed scores of people near its summit.

Kilauea is one of five volcanoes that make up the island of Hawaii. It's among the most active volcanoes in the world. The volcano is a type known as a hot spot volcano. Magma from deep within the mantle burns its way through the crust much like a blowtorch. Hot spot volcanoes can occur far from the edges of Earth's tectonic plates where most other volcanoes erupt.