Helicopter flyovers this week confirmed lava erupting from a vent on the northwest side of the Halemaʻumaʻu crater.
The western half of the lava lake was about 650 feet deep Friday morning, the USGS said in a report. The eastern half of the lava lake was stagnant.
Authorities are warning people to stay clear of the area due to various threats posing a risk to visitors.
"High levels of volcanic gas, rockfalls, explosions, and volcanic glass particles are the primary hazards of concern regarding this new activity at Kīlauea's summit," USGS said. "Rockfalls and minor explosions… may occur suddenly and without warning."
Kilauea is the youngest and most active volcano on the Big Island. In fact, with more than 30 eruptions since 1952, it is one of the most active volcanoes in the world.
This story was produced from New York City.
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