Volcano Watch — Lava from Kīlauea's East Rift Zone lessens

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The 10-year-long eruption on Kīlauea's East Rift Zone continues, with the only change being a decrease in eruption rate over the last few weeks. This decrease in rate correlates with the slowly deepening surface of the lava pond inside the Pu`u `O`o cone, as reported last week. The eruption rate, which has been roughly 400,000 cubic yards per day since mid-February, has decreased to about 200,000 to 250,000 cubic yards per day.

The lava continues to flow from the vents on the south and west sides of Pu`u `O`o to the sea in underground tubes. The main lava entry at the ocean, marked by the location of the large steam plume, carries nearly all the erupted lava into the ocean. The lava tube is characterized by a sequence of skylights from 2,350 feet to about 400 feet above sea level. Skylights are openings in the top of the tube, where the roof has either collapsed or been pushed upwards by magma pressure within the tube, and can be identified from a distance by plumes of bluish fume.

A small surface flow continues to advance down the western edge of the flow field adjacent to the Lae`apuki flow. This flow is readily accessible from the end of Chain of Craters Road in Hawai`i Volcanoes National Park. Park rangers are on duty and a new trail, less than 0.5 miles long, leads visitors from the end of the road to an area where the flows can be observed at close range. The only hazard in the area in dehydration, particularly for children. Take water and wear sturdy walking shoes.

At times, the flows cover older flows overgrown with vegetation, although most of the area being covered now was covered by lava only a few months ago. Stay back from burning vegetation, as methane can accumulate underground and explode.

There is little to see at the ocean entries, because the lava pours directly into the sea, and the interaction is veiled in steam. In addition, steam explosions, collapse of the lava bench, and acidic fume all pose serious hazards in the area. For these reasons, the Park Service has closed this area to visitors. For your own safety, obey the area closure signs posted in the area.

This column will not appear the next two weeks due to several administration meetings on the mainland. It is scheduled to return with an update of eruption activity on July 11.