The unprecedented Mauna Ulu eruption of Kilauea Volcano in Hawaii led to some spectacular imagery a few decades back. Not only was it the longest eruption on record at the time, it was also easily accessible for the public to view. This combination of factors resulted in some amazing photography.
The Mauna Ulu eruption began in 1969 and flowed fairly consistently until 1974, lasting a total of 1,774 days (just shy of five years). It was the longest-lasting and most voluminous eruption in 2,200 years, according to the U.S. Geological Society.
An observation platform was raised for the public to view the spewing lava lake in the crater, the USGS said. In 1969, some stunning pictures were taken, one of which was recently posted by the USGC for their “throwback Thursday” photograph on social media.
A fountain of lava continually gushed and spilled into the ocean 7.5 miles away for several days, from Oct. 10 to Oct. 13 of that year. The photo, credited to J.B. Judd, shows an incredible, symmetrical “dome” of lava spewing some 65 feet into the air during the eruption. The dome was one of 12 separate fountaining events that occurred that year.
Lava domes are formed by “viscous” magma that piles up around the vent of the volcano, according to Oregon State University.
USGS tweeted, “Dome fountain of episode 10, October 10–13, 1969, eruption of Kilauea Volcano. Symmetrical dome fountains such as this are rare.”
Dome fountain of episode 10, October 10–13, 1969, eruption of Kilauea Volcano. This dome fountain is about 20 m (65 ft) high. Symmetrical dome fountains such as this are rare. #Tbt #HI @Volcanoes_NPS pic.twitter.com/sKSQaVINKs
— USGS (@USGS) March 29, 2018
“Fountaining” usually happens when gas bubbles form and expand within an isolated vent in a lava fissure, causing a jet of lava to spray into the air. Sixty-five feet seems high, yet fountains typically range anywhere from 30 feet to 330 feet; some spew spectacularly as high as 1,640 feet (half a kilometer) or more.
From the photograph, the lava dome appears to be erupting in the water, but the “waves” shown in the photo are actually ripples of lava—not water.
Since the record-setting eruption of Mauna Ula ended, another eruption has claimed the title for longest-lasting. A volcanic vent on Kilauea’s east rift zone, Pu‘u ‘Ō‘ō eruption started in 1983 and has continued since then. Yet, unlike Mauna Ula, Pu‘u ‘Ō‘ō is much less accessible for the public.
“[Pu‘u ‘Ō‘ō] ranks as the longest and most voluminous known outpouring of lava from Kīlauea Volcano’s East Rift Zone in more than 500 years,” USGS said. “Lava fountains and flows have profoundly altered the landscape and repeatedly challenged residents with lava inundation.”