The summit eruption at Kilauea exhibited more vigorous fountaining Saturday evening, with spatter rising 60 to 100 feet high, mainly from the more southerly of the two active vents, according to the U.S. Geological Survey.

By 6 p.m., the increased amount of lava had covered about 20% of the floor of Halemaumau crater.

Lava output from the crater vents had been sluggish since Thursday morning, marking the beginning of the third phase of the ongoing summit eruption that began Monday. “Small, slow-moving lava flows continued to erupt but traveled only short distances from the northern vents for the next day and a half,” according to a USGS news release.

Fountaining from the southern active vent began to increase and become more continuous around 5:15 p.m. Saturday.

The USGS said tremor activity has been gradually increasing over the past two days but is still relatively low compared to the first two episodes of high fountains that shot 250 feet into the air.

“If fountaining continues, it is possible that the fountain heights will increase as more gas-rich lava (is) erupted. It is not possible to estimate how high the fountains may get or how long the fountaining will last, but prior episodes have produced fountains over 200 feet high that last up to 24 hours,” the release said.

The Kilauea Volcano Alert Level remains at “watch.” All the activity is within Hawai‘i Volcanoes National Park, and no changes have been detected in the East Rift Zone or Southwest Rift Zone.

The USGS Hawaiian Volcano Observatory is providing daily updates on the eruption and remains in close contact with Hawai‘i Volcanoes National Park and the county Civil Defense Agency.

The park provides visitor information on its website, and livestream video of the summit eruption is available at youtube.com/usgs/live.