“Ballistic blocks” were hurled into the visitors car park at Hawaii National Volcanoes Park following the blast at 4.15am local time (11.15am BST) on Thursday.
Ash fell as far as 40 miles away, reaching Big Island tourist hotspot Hilo on the south-east side.
Experts say the blast was steam driven caused by lava reacting with the water table, with biggest explosions predicted to come as the level drops lower.
One USGS geologist, Michelle Coombs, warned: “We may have additional larger, powerful events” – a worry not only for residents but for holiday-makers with plans to visit Hawaii in the next few weeks.
Officials say bookings to Big Island are already down 50 per cent on last year as the explosive eruptions continue two weeks on.
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Hawaii Tourism Authority moved to assure travellers that “Hawaii is open for business” following the latest big eruption.
Hawaii Governor David Ige said while Puna and Pahoa remained no-go areas, “the rest of the island is still a great destination”.
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He said: “The eruption site and the lava flows are in a very small portion of the island.”
Officials said the international airports in Hilo and Kona remain open and all flights into the Hawaiian Islands are operating normally.
The majority of the island’s major visitor resorts are based on the western Kohala and Kona coasts, more than 100 driving miles away from Kilauea.
A website statement added: “All accommodations, activities and attractions throughout the Hawaiian Islands are operating normally, with the exception of those in the area affected by the volcanic activity on the island of Hawaii.”
Hawaii volcano eruption: Passersby have been documenting the huge ash clouds rising
Tourists who had booked accommodation in the Lower Puna district are advised to seek alternative accommodation until further notice.
Which areas are affected?
Volcanic activity and lava flow is confined to a small 10 square mile area in the East Rift Zone around Leilani Estates and Lanipuna Gardens in Lower Puna.
The region sits at the south-east side of Big Island.
Hawaii volcano eruption: Lower Puna has been hit by fissures and toxic gases
Big Island is 4,028 square miles wide, while the Puna district is approximately 500 square miles wide.
A red aviation alert was issued on Wednesday but no additional explosions have been reported in the last few hours.
The latest air quality reports from the Department of Health are rated ’good’, apart from the affected area surrounding Kilauea.
British nationals are advised to monitor local media reports and following local authorities’ advice, according to the latest advice from The Foreign and Commonwealth Office (FCO).