Kupaianaha: 1986-1989

In July 1986, just as it appeared that Puu Oo would start the 48th episode, magma began to erupt from new fissures at the base of the cone (Heliker and Wright, 1991). Another fissure opened 2 miles (3 km) down rift to form the Kupaianaha vent. Episode 48, sometimes called the Kupaianaha eruption, was to become the longest of all the eruptive episodes to date.

A Change in Eruptive Style

With the change to the new vent, the style of eruption also changed. Unlike the discontinuous, high-fountaining eruptions of Puu Oo, Kupaianaha erupted continuously with gentle effusion of lava. A lava pond developed over the Kupaianaha vent. Repeated overflows of the lava pond built a 180-foot (55 m) tall shield in less than a year (Heliker and Wright, 1991). In this photo, the surface of the pond is covered by a thin crust of solidified lava. The Puu Oo cone is in the background. Photograph by J.D. Griggs, U.S. Geological Survey, January 13, 1987.

The cause of the change in eruptive style is a topic of continuing research. Prior to the eruption, a reservoir of magma existed in the east rift zone beneath the present location of the Puu Oo vent. This local reservoir may have played a role in triggering or sustaining fountaining episodes. No magma was stored in the rift zone below the site of the Kupaianaha eruption. The magma that arrived at Kupaianaha contained less gas because most of the gas escaped as the magma passed beneath Puu Oo. Gas is need to generate fountaining eruptions. Although volcanologists have numerous monitoring techniques, it can still be difficult to determine exactly what controls the behavior of a volcano.

Lava Meets the Ocean

The Kupaianaha lava pond (just to the right of center on the skyline) provided a steady supply of lava to flows advancing toward the ocean. Lava flows crusted over or inflated to produce lava tubes. Lava tubes insulate the lava; thus, they remain fluid and can travel great distances (6.9 miles; 11 km in this photo) from the vent to the coast. The upper tube system is marked by a series of steaming areas. By late 1986, lava tubes reached the ocean near the small community of Kapaahu. Eleven homes were destroyed. In early 1987, lava flows traveled farther to the east and destroyed 14 homes in the Kalapana Gardens subdivision. In this photo, the Puu Oo cone is on the skyline to the left of center. Kupaianaha is the shield on the horizon near the right margin of the photo. Aa from the Puu Oo eruptions flowed down Pulama Pali. Some flows buried portions of the Royal Gardens subdivision. Note the roads and houses. Pahoehoe lava of the Kamoamoa flow field is on the left and bottom of the photograph. Photograph by J.D. Griggs, U.S. Geological Survey, December 28, 1987.

The upper part of the tube system is marked by a series of steaming areas. Kupaianaha is at the bottom of the photo. The steam plume produced by lava pouring from the tube into the ocean is in the top right corner. The distance from the vent to the ocean is about 6 miles (10 km). Photograph by J.D. Griggs, U.S. Geological Survey, April 21, 1988.

Thermal infrared map of the Kupaianaha flow field. The underground storage and transport of lava in the tube system is shown in yellow from the top to the bottom of the slide. The bright colored area at the bottom of the slide is the plume of hot water produced by lava entering the ocean. Photo by V.J. Realmuto, Jet Propulsion Laboratory, California Institute of Technology, October 1, 1988.

Lava continued to pour into the ocean from mid-1987 through 1989. During this period, several major lava tubes developed and broke down. New lava tubes and breakouts from developed lava tubes increased the size of the lava flow field. The interaction of lava and water generated an acidic steam plume, black sand, and, with the proper conditions, littoral cones. Photograph by T.J. Takahashi, U.S. Geological Survey, February 10, 1988.

Wahaula heiau was constructed in the 13th century during a change to more strict worshipping rituals. Wahaula was the first luakini heiau and remained in use until 1819. In 1938, the Kalapana Extension Lands were added to Hawaii National Park. In 1965, the National Park built the Wahaula Visitor Center to interpret the cultural features of the coastal area. Photograph courtesy of National Park Service, October 1967.

By June 1989, lava destroyed Wahaula Visitor Center. Photograph by J.D. Griggs, U.S. Geological Survey, June 22, 1989.

Subsequent flows surrounded Wahaula heiau (bottom center). Several homes in Hawaii Volcanoes National Park and the Royal Gardens subdivision were also overrun by lava. Photograph by C. Heliker, U.S. Geological Survey, May 11, 1994.

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