Kilauea: 20 years on, it's still erupting. (Earth Science).

As of Jan. 3, Hawaii's Kilauea volcano has been erupting continuously for 2 decades. During that period, this Energizer Bunny of volcanic activity has repaved more than 110 square kilometers of mountainside, as well as 13 km of local highways.

Lava that has flowed 10 km or more to reach the Pacific has created about 2.2 [km.sup.2] of new oceanfront property and black-sand beaches. At some spots along the coast, hardened lava is 25 meters thick. In all, Kilauea has coughed up more than 2.3 cubic kilometers of molten rock since 1983.

Despite the longevity of Kilauea's eruption, lava output remains high, says Don Swanson of the U.S. Geological Survey's Hawaiian Volcano Observatory near Hilo. Each day, the volcano produces nearly 350,000 cubic meters of lava--that's about 45,000 dump truck loads--and emits 1,800 tons of sulfur dioxide gas. This noxious gas reacts with water vapor, sea spray, dust, and other atmospheric constituents to form volcanic smog, also known as vog.

In the past 20 years, Kilauea has destroyed nearly 200 homes and other structures, causing $61 million in damage. The ongoing eruption is one of the volcano's lengthiest in the past 600 years, Swanson notes. The USGS released statistics about Kilauea late last year.--S.P.