Volcano Watch — Eruption continues without interruption

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The eruption at the episode 51 vents on the west flank of Pu`u `O`o continued without interruption again this week. The eruption is little changed from a week ago, when we reported that a lava pond had formed just west of the vent. The pond is overflowing and sending a surface-fed pahoehoe flow to the south. 

Eruption continues without interruption...

Eruption continues without interruption

(Public domain.)

The eruption at the episode 51 vents on the west flank of Pu`u `O`o continued without interruption again this week. The eruption is little changed from a week ago, when we reported that a lava pond had formed just west of the vent. The pond is overflowing and sending a surface-fed pahoehoe flow to the south. The flow had reached the edge of the forest at about the 2,300-foot elevation, and was burning some forest by Thursday afternoon.

The Pu`u `O`o cone still contains an active lava lake, which is about 130 feet in diameter and about 175 feet below the spillway on the east side of the cone. There are two areas within the lava lake where active bubbling and degassing produce fountains less than 10 feet high. The pond rose rapidly by about 35 to 40 feet several times last Sunday, and flows covered the entire floor of the Pu`u `O`o cone with active lava.

The continued deflation of the summit this week indicates that more magma is erupting than is being introduced to the magma reservoir from below. The rate of deflation increased during the week and was moderate by Thursday and Friday. The eruption is becoming more steady-state as the pond begins to cover over the vent. After more than a month of building a local shield, the flows are now becoming channelized, and lava flows are progressing farther from the vent area. If the eruption continues, we expect to see the channels evolve into tubes, and the flows to continue to advance to the south. The projected flow path is well west of what remains of the Royal Gardens Subdivision and entirely within Hawai`i Volcanoes National Park.

There were several earthquakes early this week with magnitudes greater than 3.0. The first, of magnitude 3.1, occurred April 10 at 5:40 p.m. and was located seven miles beneath the south flank of Mauna Loa in the Kapapala Forest Reserve. The same day at 7:53 p.m., another magnitude 3.1 earthquake occurred about 30 miles beneath the southwest submarine slope of Kahoolawe Island. The following morning at 9:39 a.m., a seven-mile-deep, magnitude 3.5 earthquake rattled the south flank of Kīlauea Volcano near the east end of the Hilina Pali. Later on April 11, at 8:27 p.m., another magnitude 3.1 earthquake occurred about three and a half miles deep just east of Ocean View Estates.

After this busy start, the week settled down to more normal seismic levels with numerous smaller earthquakes, but none larger than magnitude 3.0.

This past week, EOS, the newsletter of the American Geophysical Union, a professional organization of geologists and geophysicists, reported on the House Budget hearings for the U.S. Geological Survey. Their story reported that a proposed nearly 30 percent reduction in the funding for the Volcano Hazards Program (which is the dominant source of funds for the Volcano Hazards Observatory) could lead to closure of certain field offices of the U.S. Geological Survey, including the Cascade (Mount St. Helens), Alaska, and Hawaiian Volcano Observatories.

These proposed reductions are included in the Administration's budget for the U.S. Geological Survey submitted to Congress by the Department of the Interior. Such large proposed reductions would come at the end of more than 10 years of decreasing budgets (corrected for inflation) for the Hawaiian Volcano Observatory. It is not part of the present plan of the U.S. Geological Survey to close the Hawaiian Volcano Observatory. However, we are currently working to further streamline our operations so that we can continue to provide essential hazard information about volcanic eruptions and earthquakes that may affect your lives, homes, and livelihoods.