KILAUEA VOLCANO, BIG ISLAND (HawaiiNewsNow) - Ash plumes continue to spew from Kilauea's summit crater, sending ashfall on downwind communities.
On Tuesday morning, the U.S. Geological Survey reported a 4.5-magnitude quake happened around 2 a.m. near the Kilauea summit, following a large eruption that sent an ash plume about 15,000 feet into the air. The Pacific Tsunami Warning Center said the quake did not trigger a tsunami.
Meanwhile, geologists said some rocks have also been spewed out of the crater. It's unclear how big the rocks were.
The ash and other volcanic emissions from the crater are prompting growing air quality concerns.
On Tuesday, the state Health Department said particulates and gases in the air had created "unhealthy" air conditions in Kona. Those with heart or lung disease, children and the elderly are being urged to avoid prolonged exposure.
Explosive eruptions at the summit crater have been happening for weeks, but are now happening with greater frequency.
Geologists say there's no telling when the explosions will end, and that eruptions are possible at any time.
Before the eruptions began, scientists had warned that explosions at the summit could send heavy ashfall across communities near the summit and toss boulders "the size of cows" as far as a half a mile.
Given the threat, Hawaii Volcanoes National Park remains closed, and civil defense officials are urging those who live near the crater to remain vigilant.
The news comes as civil defense authorities continue to respond to Kilauea's ongoing eruptions in lower Puna, where thousands of people remain under mandatory evacuation orders.
The last time steam-induced eruptions happened at Halemaumau Crater was nearly a century ago, when flying debris killed one and left a layer of ash over homes and cars. In 1924, explosive events at the summit lasted for two and a half weeks and ash reached as high as 20,000 feet above sea level.
Scientists say they're using the 1924 event as something of a baseline, using it to determine how long this volcanic event might last and how strong eruptions could be.
This story will be updated.