Kilauea volcano lies at the center of activity in Hawaiʻi Volcanoes National Park. The unassuming bump on Mauna Loa's southeast flank would be easily overlooked if not for its massive steaming crater and crater-within-a-crater, Halemaʻumaʻu, which has spewed lava nearly continuously over the last 25 years.
Researchers initially thought Kilauea was just a vent of Mauna Loa, but later discovered a separate lava system – a particularly active system that first broke the earth's surface as early as 600,000 years ago. How active Kilauea Volcano will be when you visit is subject to the whims of Pele, the Hawaiian goddess of fire and volcanoes who makes her home here, so set expectations low, and hope to be pleasantly surprised.
If Halemaʻumaʻu and Puʻu ʻOʻo are erupting, they belch thousands of tons of the gas daily. When lava meets the sea it creates a "steam plume," as sulfuric and hydrochloric acid mixes with airborne silica (or glass particles). All this combines to create vog, which, depending on the winds, can settle over the park. People with respiratory and heart conditions, pregnant women, infants and young children should take care when visiting if an eruption is taking place. Follow hawaiiso2network.com for air quality reports.
In 1823, missionary William Ellis first described the boiling goblet of Halemaʻumaʻu to a wide audience, and his fantastic account attracted travelers from all over the world. Looking in, some saw the fires of hell, others primeval creation, but none left the crater unmoved. Mark Twain wrote in 1866 that he witnessed: "[C]ircles and serpents and streaks of lightning all twined and wreathed and tied together…I have seen Vesuvius since, but it was a mere toy, a child's volcano, a soup kettle, compared to this."
Then, in 1924, the crater floor subsided rapidly, touching off a series of explosive eruptions. Boulders and mud rained for days. When it was over, the crater had doubled in size – to about 300ft deep and 3000ft wide. Lava activity ceased and the crust cooled. But not for long. Since then, Halemaʻumaʻu has erupted 18 times, making it the most active area on Kilauea's summit.
All of Hawaiʻi is the territory of Pele, goddess of fire and volcanoes, but Halemaʻumaʻu is her home, making it a sacred site for Hawaiians.