Multimedia Archives

Kamokuna Lava Bench
Continues to Grow

This update is current as of October 23, 1998. Eruption updates are posted every 4 to 6 weeks; more frequent updates will be made when there are drastic changes in activity or when residential areas are threatened by lava flows. Update archive.

Aerial view of new pahoehoe flow approaching the shoreline, Kilauea Volcano

Photograph by J. Kauahikaua on October 16, 1998 Aerial view to west shows newest pahoehoe flow moving toward the coast. Lava feeding this flow emerged from a lava-tube skylight near the base of the pali (cliff in upper right) on October 9 and reached the sea on October 19.

Overview

The eruption of Pu`u `O`o continues to deliver lava to the sea through small intermittent surface flows and a new lava tube that developed on the coastal plain after a pause in magma supply to the vent August 12-14. A relatively wide (150 m) lava bench has grown west of the prominent littoral cone at the entry point and surface flows here have obscured the old sea cliff that once marked the relatively safe viewing areas for visitors. Dense volcanic fume from Pu`u `O`o has obscured its crater for the past several weeks, and no lava has been seen in the crater for many months.

Pu`u `O`o Vent Still Source of Lava and Sulfur Dioxide Gas

Pu`u `O`o spatter and cinder cone,
Kilauea Volcano

October 22. In the past several weeks, Pu`u `O`o has released about 2,000 tonnes/day of sulfur dioxide gas into the atmosphere. This gas discharge is equivalent to the gas contained in about 400,000 m³ of lava, which agrees well with direct measurements of lava discharge made above the lava tube about 5 km from the vent. We have not observed lava in the crater for several months but it first passes beneath the vent before entering the lava tube through which it travels to the sea.
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Roof of lava tube collapses

New skylight above lava tube, Kilauea Volcano

October 20. A new skylight recently formed above the lava tube at an elevation of about 635 m. Lava moving through the tube is 7-9 m below the surface! Since this part of the tube formed in August 1997, flowing lava has eroded the underlying lava flows to form a tube that is taller than it is wide. Lava erodes the underlying lava flows by melting and mechanically eroding or abrading the brittle rocks beneath.
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Small bench collapse

	Note lava oozing into the sea left of the arrow; this part of the bench collapsed into the sea a few hours later.
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	Geologist stands atop the former sea cliff above the active lava bench. Note absence of new lava left of the arrow, which marks the same location as in the top image.
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September 22. Views of the east (foreground) and the more active west (background) lava-entry areas of the Kamokuna bench. The growing edge of the eastern most bench area slid into the sea between 1 and 4 p.m. Many such collapses occur as new land is added to the shoreline.

Overview of Kamakuna Bench

Aerial view of Kamokuna lava bench, Kilauea Volcano

Photograph by J. Kauahikaua on September 24, 1998

Aerial view of long Kamokuna lava bench on the southeast coast of Kilauea Volcano. Note location of the former sea cliff. The bench is about 150 m wide at the west entry area (large white plume).

Photograph by J. Kauahikaua on October 22, 1998

Aerial view of long Kamokuna lava bench on the southeast coast of Kilauea Volcano. Note location of the former sea cliff. Lava travels about 12 km through lava tubes from Pu`u `O`o to the coast.

Flow-field Map

Map showing area covered by lava flows emplaced during the Pu`u `O`o - Kupaianaha eruption between 1983 and August 30, 1998. Flows emplaced between August 14 and August 30 are shown in purple. A new lava tube is developing within this flow area and is delivering lava to the sea 300-400 m west of the east Kamokuna lava tube (black line). On October 19, a surface flow moving from the base of Pulama Pali reached the sea about 100 m west of the the area shown in purple.

Update Archive

Eruption-viewing opportunities change constantly, so those readers planning a visit to the volcano should contact Hawai`i Volcanoes National Park for the most current eruption information (ph. 808-985-6000).

Additional photographs and descriptions of the Pu`u `O`o - Kupaianaha eruption may be found at:

The URL of this page is: http://hvo.wr.usgs.gov/multimedia/archive/19981023/main.html Contact: hvowebmaster@usgs.gov
Updated: 16 December 1998

Kamokuna Lava Bench Continues to Grow