HILO — Kilauea’s summit lava lake is the highest it’s been in more than a year.
The lake inside Overlook crater, which sits inside Halema‘uma‘u Crater, continually rises and falls in concert with magma pressure below. As of Monday morning, this cycle had pushed it to just 33 feet below the Overlook rim, making it visible from a safe distance at Jaggar Museum.
Hawaiian Volcano Observatory spokeswoman Janet Babb said it was last that high on Jan. 4, 2017.
The lava has been rising since Friday but it’s not known how long that trend, which can quickly reverse, will continue.
“Overall, it’s been on the high side” recently, Babb said, referring to the lake level. “With this latest inflation, it’s just pushing up even higher.”
Occasionally, the lake will go high enough to spill onto the floor of Halema‘uma‘u Crater. That happened in October 2016 and April and May 2015, Babb said.
But it’s not the only volcanic activity of note.
On April 10 and 11, HVO detected a swarm of small earthquakes between 5 and 10 kilometers below the summit.
Brian Shiro, HVO seismologist, said that’s a result of magma moving through the volcano’s plumbing. It occurred at the right depth to be located within or around the lower magma chamber.
“It stands to reason that something changed down deep,” he said. “I caution to make a direct correlation there,” Shiro added, referring to the rise in the lava lake.
He said there were 194 small temblors counted. Most were of magnitude-2 or smaller and were too weak to be felt.
Shiro said such swarms happen every couple of years, often with no apparent effects on eruption activity at the summit or Pu‘u ‘O‘o.
He noted there have been four such swarms in about as many months, which is unique.
HVO reported Monday a slight increase in seismicity in the Upper East Rift Zone overnight.
Email Tom Callis at tcallis@hawaiitribune-herald.com.