Volcano Watch — Kīlauea lava resumes ocean flow

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The eruption along Kīlauea's East Rift Zone paused briefly a week ago, beginning Friday morning but activity had resumed again by last Sunday afternoon. Friday, July 23, began near the Pu`u `O`o vent with a small sequence of collapses, which we recorded on a nearby seismograph station. By daybreak that morning, the flow of lava into the sea had stopped and only occasional small, steam plumes were generated as hot blocks of the lava bench collapsed into the sea.

Commercial helicopter pilots reported to us that the skylights in the tube were empty as high as 1,500 feet above sea level, demonstrating that the tube had drained. Above 1,500 feet, the visibility was so poor that no observations could be made. A brief glimpse into the Pu`u `O`o cone on Saturday revealed that the lava pond was higher than had been seen in the last few weeks and had been fairly active. However, the poor weather over the weekend precluded further observations.
By last Sunday afternoon, a small `a`a flow was advancing down the main pali, but the volume of lava was very small. We have inferred that the collapses at the cone on Friday morning correspond to the time the vent shut off, and that some time early Sunday afternoon, the eruption had started up again. The startup was very gradual, and we cannot identify any particular time when the ground vibration or tremor near the vent increased.

By Monday morning, the lava had reoccupied the old tube system all the way to the base of Paliuli, just above the buried Chain of Craters Road near Kamoamoa. Here, the tube had collapsed, and lava was flowing through the collapsed top of the tube and was spreading out in a massive pahoehoe sheet flow. The flow advanced in two directions with a more active western flow and a smaller eastern flow. These two new flows advanced along the margins of the Kamoamoa flows emplaced earlier in the eruption.

Tuesday morning, the western flow had again reached the ocean, and a steam plume was visible. The flow entered the ocean over a broad front and has yet to consolidate to a narrow tube, as we had noted before the pause in the eruption. By Wednesday morning, the eastern lobe of the flow had also reached the ocean, producing a second steam plume. These lava entries have been gradually extending the coast and are producing new black sand where the hot lava explosively interacts with seawater. At times, plumes of black sand and spatter are thrown 50-80 feet high, but most of the activity is less spectacular.

The western lava entry into the ocean is close to the end of Chain of Craters Road. The National Park Service has marked a new trail to lead visitors to areas where they can view the lava in relative safety. The coastal area is commonly hot, and the well-equipped visitor will wear sturdy shoes, long pants, and a hat. Remember that the lava is over 2,100°F and that the heat can lead to dehydration and will also produce radiant burns if you stand too close for too long. Obey the area closure signs posted by the Park Service to keep visitors out of unstable areas.