Skip to main content

The Apex and the (Possible) End of Fissure 8

Have we seen the last days of Fissure 8? Or is it merely sleeping.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


We left Fissure 8 busily devouring Vacationland and Kapoho Bay. By the next day, June 7th, the lava flow pumped out by those industrious fountains had built a delta 1.2 miles wide. That was just the visible flow: the water upwelling around 1,000 seaward of the new shoreline suggested part of the flow front was happily tooling along on the seabed quite a ways out.

Aside from some small steam explosions at the ocean entry on June 10th, things at the channel's end remained about the same. Meanwhile, at the fountains of Fissure 8, the new cone (pu'u in Hawaiian) continued to grow. By June 11th, the cone had grown to about 115 feet at its tallest point, while the highest fountains soared over it at 180 feet. It grew by bounds over the next 24 hours, reaching 140 feet by the evening of the 12th. Things were also getting more exciting at the ocean entry, where the channel had added a second large entry point and many smaller ones.

The Fissure 8 cone reached its full height of 180 feet by June 24th, after some particularly vigorous fountains shot up to 246 feet on the 19th. In the remaining weeks of the eruption, the fountains would only rarely rise above the rim; they would have been barely visible if not for the large gap where the lava spilled through. These fissures don't produce cones in the typical cinder cone shape, with steep sides rising to a crater at the summit. They're more like horseshoes, curved in a round-bottomed U shape. And they look striking with fountains pulsing within and brilliant red-orange flows gushing from their open sides.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Fissure 8 and its channel on July 29th, 2018. Credit: USGS

At the ocean, new coastlines grew by nearly 150 acres in a week. By the 25th, the flow front there was nearly two miles wide. Pele's latest real estate building project continued apace, with no signs of slowing down.

The lava in the channel stayed incandescent for quite some time, but by June 27th, it had crusted over half a mile from the ocean entry. This is common: lava on the outside of a flow cools and crusts over fairly quickly, while within the crust molten rock continues its journey, insulated from the cool air outside. It's how lava tubes form and is a common occurrence on Kilauea.

On the 4th of July, we got quite the fireworks display from a lava whirl. Downstream of Fissure 8, a few channel blockages temporarily caused overflows from the main channel. This was the beginning of a substantial change: the flow's path to the ocean choked off around July 6th, stalling just over a mile from the ocean entry. By July 9th, the flow had found a new route along the south margin of the original flow. A blockage in the channel upstream of Kapoho Crater kept most of Fissure 8's lava from reaching the ocean, but the fountains continued pumping.

For a brief time on the 10th, it looked like lava would retake the original channel, but the blockage returned and diverted the flow to the west of Kapoho Crater. It came close to the ocean, reaching to within two thousand feet of the coast at Ahalanui Beach Park by 10am; it destroyed a charter school and the park that night, establishing a powerful new ocean entry. Lava still drained into the ocean from many other points along the now 3.7 mile wide flow front, creating a pretty spectacular ocean entry.

By July 12th, a new phenomenon had become apparent: each time Kilauea's summit experienced a collapse event, lava levels at Fissure 8 surged for a few hours. It showed how the plumbing throughout the volcano is closely connected, and led to some pretty dramatic footage as searing-hot lava suddenly gushed through the channel.

A wee lava island appeared in the ocean on July 13th, which was probably not one of the most significant events but certainly one of the prettiest. A dramatic set of explosions on the 16th proved how dangerous the meeting between molten rock and water is. A lava bomb fell on a tour boat, injuring dozens of people and giving the world a stark reminder that even relatively calm volcanoes like Kilauea are extremely hazardous.

Over the next several days, lava lobes and overflows continued to threaten (and sometimes consume) homes. Levels in the channel fluctuated and seemed less responsive to summit collapses, but new land continued to be formed at the ocean entry and further land was covered by new lobes and overflows. Small brush fires ignited by lava burned a few acres here and there. It seemed, as the days ticked over into August, that Fissure 8 may continue on like this for months.

And then, things changed.

The situation turned on a dime on August 4th. That morning, the Fissure 8 channel was active and incandescent, even adjusting its path, overflowing here and there, and starting more fires. By the late afternoon, the fountains were pumping considerably less lava. By the following morning, the output had become significantly lower, and the channel already crusted over from the spillway at the mouth of the cone all the way down its considerable length. Instead of flowing, lava now merely oozed. On the 6th, observers reported that the once mighty fountains now merely bubbled a bit within the crater of the cone. Lava had drained from the upper channel and crusted completely over down-channel. Over the next couple of weeks, even the bubbling stopped; the lava ponds within the crater have formed thick dark crusts, and after the pause stretched beyond two weeks, it seemed the eruption may be over.

The drained Fissure 8 cone on August 8th, 2018. Credit: USGS

But while Pele sometimes naps, she rarely sleeps for long. And she may not yet be done with Fissure 8. On August 21st, scientists conducting an overflight of the Lower East Rift Zone discovered gas jets throwing glassy, light-gray lava from within the cone.

It's too early to count Fissure 8 out. But even if it never roars back to life, it will always be a superstar.

Many thanks to the volcanologists of the USGS and the Hawaiian Volcano Observatory, whose hard work observing Kilauea's eruption provided the information contained in this two-part series.