Quick Summary of 2018 Kīlauea Eruption

In May 2018, Kilauea Volcano sprung a leak.

For a decade before that, there had been an active lava lake at its summit, nestled inside Halemaʻumaʻu Crater inside a larger caldera. There was also a side vent on the volcano’s shoulder, Puʻu ʻŌʻō, erupting lava for 35 years.

On April 30, the pipes burst under Puʻu ʻŌʻō. All the lava from it and the summit lava lake drained down a “rift zone” (faults and cracks) to a residential area 25 miles away, on the southeast tip of the island. Lava started erupting in the Lower East Rift Zone (LERZ) on May 3, and continued through early August.

With all that magma (lava when it’s underground) draining away from the summit of the volcano, Halemaʻumaʻu Crater fell in, and the larger caldera around it sank hundreds of feet as well, revealing sulfur banks and other features not seen since Mark Twain visited in the 1800s. These changes didn’t happen all at once, but in stages. During July there were almost daily collapses with shaking equivalent to an M5.3 earthquake (see my video archive).

For a video summary of this eruption and those that preceded it, see this excellent 10-minute history of Kilauea’s eruptions.

This blog is a record of the 2018 Kīlauea eruption, with photos, videos, and info from scientists who study it. I posted daily for the first three months of the eruption, and switched to weekly after the lava in the LERZ stopped gushing and the summit stopped collapsing in on itself.

There’s still a little activity— this volcano almost never goes completely quiet— but for now, residents are holding their breath to see if this eruption is really and truly over.

June 6: Summit Explosions Explained (And Predicted!)

USGS/HVO photo of Fissure 8, spatter cone and rainbow, June 6.
Today’s Eruption Update:

Last night, USGS scientist Steve Brantley explained the current eruption in an informative 10 minute talk. I transcribed it as a separate post, but here’s a rough summary: Magma heading down to the Lower East Rift Zone is causing the summit to deflate. Deflation is causing a pattern of more and more earthquakes over 30-50 hours until the summit releases the strain with an explosion, accompanied by an ash cloud.

Sure enough, there was an M5.6 explosion and 10,000 foot ash cloud at 4:32pm. HVO’s Twitter account had a great impromptu Q&A session about it (see below).

Meanwhile, down in the Lower East Rift Zone, Fissure 8 shows no signs of slowing. It’s wiped out Vacationland and nearly all of Kapoho Beach Lots, and is continuing to create new (crumbly, hazardous) beachfront real estate.

USGS has also been posting some striking imagery today.

Video description: “HVO’s mid-day overflight on June 5 shows ongoing partial collapse of Halema‘uma‘u at the summit of Kīlauea Volcano. To the north of the former visitor Overlook parking area (closed in 2008) is the site of the former lava lake—now a deep hole piled with wall-rock rubble. The western portion of Halema‘uma‘u has moved down and toward the center of the crater as new cracks form on the caldera floor to the west. Kīlauea’s summit continues to subside due to withdrawal of magma towards the volcano’s East Rift Zone.”

They’ve also posted drone footage of Fissure 8 lava flow on June 3. Houses give a sense of scale:

(Link to video description)

Here’s this morning’s USGS helicopter overflight of Fissure 8:

More images, lots of great geology info below the cut. But first, a 2-minute USGS briefing, since we skipped yesterday’s:

Continue reading June 6: Summit Explosions Explained (And Predicted!)

June 1: Halema’uma’u Exposed

Today’s Eruption Summary

Fissure 8 continues to pump out vast amounts of lava, although it’s slacked off a tad from yesterday’s 260-foot display. One of its fingers burned a building or two at PGV. Other lobes closed in on Kapoho throughout the day, touching Highway 132 again half a mile north of Four Corners at 3:30. Fissure 18, which has been sending a flow east and down towards the ocean, has pretty much stalled apart from some small breakouts. Authorities were ordering Kapoho-area residents out today before lava cuts their only remaining road to the rest of the island.

Update: just as I was about to hit post.

(That’s a photo of Four Corners, which is the intersection of  Hwy 132 & 137. Apparently the lava’s started using 132 as a shortcut again.)

The summit has been steaming and vogging away, but the overlook vent has now been choked with debris falling from its walls. Ash explosions have nearly stopped since the 11am May 30 ash eruption that rose 12,000 ft.  Scientists are trying to figure out whether this means the main explosive phase is finished, or whether it’s going to build up enough pressure to blow out the clog. (That said, the crater has not “fallen quiet,” as many non-Hawaiian news stations claimed today. According to @NWSHonolulu, there was a minor “burp” of ash just after 1:30pm.)

Fantastic Kilauea Photo Gallery

@cheaptarts pointed me to photographer Andrew Richard Hara’s amazing Kilauea Instagram. A couple examples:

20180522 @ 03:30 HST – Methane field flames simmer in new cracks from Fissure 15 and 19 open up on the southeastern side of PGV, burning a State of Hawaii warehouse next to Pohoiki Road. Slow moving pahoehoe begins to approach PGV land at a crawl. . If you are worried about PGV, please remember that there are 23 fissures that have and emitting HF, H2S, and SO2 gases throughout this entire eruptive series. I'm not an expert by any means, but I try to remind myself that the gases that could be released at PGV are already being released into the atmosphere as we speak, outside of PGV's property. . For those who are wondering, I have official permission to be documenting this area. All areas that I have documented throughout this eruptive series have been through approved with legal access. Please kokua and do not attempt to trespass in areas unless official approval has been granted. . Many areas are now becoming inaccessible and the majority are dangerous due to volcanic hazards. . My respect and best wishes go out to the neighborhood of Leilani Estates, Lanipuna Gardens, and the areas within and between Kapoho. . #leilani #lava #pohoiki #lanipunagardens #bigisland#lavaflow #hawaii #geology #fissure #volcano @hawaiinewsnow

A post shared by Andrew Richard Hara (@andrewrichardhara) on

20180529 @ 15:30-19:30 HST – Fissure 8 on Luana Street . Moderate southwest trade winds shifted gaseous plumes of smoke and gas while Pele’s hair, light fragments of cinder, and reticulate showered from the skies up to five blocks (up to Alapai Street) in radius F8’s eruptive site. F8 generated massive channels of lava extending partially east and north over older flows on Luana Street. Nearby, F24 sputtered glimpses of orange lava a few feet in the air and is unlikely to be contributing any major part in F8’s aggressive effusion rate. Massive bodies of new pahoehoe lava beds radiated an intense amount of heat, keeping ambient temperatures consistently within ~90°F at our location. . All areas that I have documented throughout this eruptive series have been through approved with legal access. Please kokua and do not attempt to trespass in areas unless official approval has been granted. The majority of my efforts are without pay and all expenses are out of pocket. The content shared is being shared without cost to our local news networks for community awareness and support. Some footage does help to pay a very small portion of my expenses. . Many areas are now inaccessible and the majority are dangerous due to volcanic hazards. . My respect and best wishes go out to the neighborhood of Leilani Estates, Lanipuna Gardens, and the areas within and between Kapoho. My heart especially goes out to all of my friends who have lost their homes in this fissure eruption. I am at a loss of words. _____ #leilaniestates #eruption #bigisland #helicopter #hawaii #aerial #volcano #lanipunagardens @hawaiitribuneherald @hawaiinewsnow @natgeo @milekalincoln @bruceomori

A post shared by Andrew Richard Hara (@andrewrichardhara) on

Pretty, huh? Okay, let’s get down to the day’s Kilauea news, views, and eruption information:

Continue reading June 1: Halema’uma’u Exposed

Video Clips: Pāhoehoe vs A’a (What’s the Difference?)

If you’ve followed this blog at all, you’ve come across the terms “pāhoehoe” and “a’a.” They’re Hawaiian words borrowed by volcanologists as technical terms for different types of lava. How can you tell which is which?

When I visited in 1986, the joke was that “a’a” is the noise you make when you walk on it, because it’s prickly, and “pāhoehoe” is the smooth stuff. But that’s oversimplified, and it confused me. Some of the old pāhoehoe flows we hiked on near Mauna Ulu seemed pretty bumpy to me.

Pāhoehoe lava is runny, faster-moving, and often described as “ropey.” It’s pretty obvious when it’s spilling into a crater or running swiftly in a river. Sometimes it has ripple marks. At other times, the leading edge slows down and turns blobby. Here’s an excellent USGS video of a pahoehoe front in night and day, May 24-25:

Pāhoehoe moves forward by inflating lobes of lava with fresh new lava from within.

Then there’s a’a lava: a crumbly, chunky mass of what looks like a heap of rocks and gravel and dirt, except it’s red-hot under the outer skin. It moves like a horizontal landslide in slow motion, bulldozing everything in its path:

It advances mostly by chunks tumbling forward off the front.

A’a is usually quite slow. You can outwalk it. In fact, you’d usually have time to pack a small suitcase if it showed up at the end of your street. Whereas when pāhoehoe flows downhill or becomes “channelized,” making itself a smooth chute, you can’t outrun it:

Both kind of lava make crinkly noises, but I think of a’a as “clinkity clankity” lava, whereas pāhoehoe tends to slither.

So now you’ll know how to explain it the next time someone asks, “What’s the difference between pāhoehoe and a’a?”

May 23: Blue Flames? Now You’re Just Showing Off

Kilauea’s chief resident has found another way to amaze and/or injure people reckless enough to get too close to her redecorating:

I had a hunch the Lower East Rift Zone webcam would be interesting tonight. I wasn’t disappointed:

I see what they mean about the Leilani fissures further west (uprift, towards the camera) reactivating today.

Edited to add: Yikes.

It’s 11:06 PM in Hawaii; second screengrab an hour or so later.

I was about to hit post, when I saw erstwhile reporter Mileka Lincoln and her crew posted this. Wow.

(recorded just an hour ago at time of this post.)

Now, let’s have the evening roundup of poignant news, amazing views, and interesting science…

Continue reading May 23: Blue Flames? Now You’re Just Showing Off

May 18/19: Good Summary of Eruption to Date

USGS aerial view of lava flow, May 19. (full-sized)

Volcanologist Erik Klemetti pulls everything together for us, reviewing how the Leilani Fissure lava eruptions and the summit ash/steam eruptions have progressed.

Link:

Kilauea Eruption Continues: How Long Could It Last?

The eruption at Kīlauea is still captivating the nation, as it should because this volcano hasn’t behaving like this in almost a century. I thought I’d take a moment to step back and review of the main events so far and what it might all mean for Kīlauea and the people who live around the volcano. These eruptions are separated by a long way if you look at the satellite data and should almost be treated at two different events..


Also, here’s today’s CivilDefense briefing and BigIslandVideonews’ splice of afternoon USGS briefing with geologist Carolyn Parcheta plus recent video footage.

Taking from video  (basically telling us which fissures are doing what):

Continue reading May 18/19: Good Summary of Eruption to Date

Hazards in Hawaii: Most of the State Is Just Fine, Thanks

I wasn’t going to do this, because hazard information is best left to emergency officials and experts.

But I don’t want the videos and images I’m sharing to mislead people into thinking this event is larger-scale than it is. It’s overwhelming to those who have lost homes or had to evacuate. I don’t want to downplay what they’re going through. At the same time, major hazards are confined to a very limited area, yet news media are whipping this up to apocalyptic proportions and tossing out headlines with “fears” and “anxieties” and “major” to scare people. I don’t want to add to their hype. A volcanic eruption one can watch from a few miles away without dying is moderate, not major.

So let me try to give a rundown of Kilauea hazards, and why I think it’s not greedy nor crazy for officials to be urging tourists not to cancel their visits.

Hazards from the Current Kilauea Eruption

Continue reading Hazards in Hawaii: Most of the State Is Just Fine, Thanks

About the 1790 Kilauea Eruption

Here’s a summary and primary sources collected by HVO geologist Don Swanson on a 1790 explosive episode of Kilauea.

Also see USGS factsheet, “Explosive Eruptions at Kilauea, Hawai’i?” compiled prior to the 2018 eruptions. Diagram from this page:

3-part diagram: at left, a full lava lake with a long chimney of magma supplying it from below; in the middle is the same lava lake with the lava level dropping way down the chimney, below the water table, so that the upper walls of the chimney are cool enough for groundwater to seep in. Rocks falling from the chimney's walls are starting to choke it. The third and last phase of the diagram shows that groundwater has heated to steam and built up pressure below the rockfall until it builds up enough steam to shoot the blockage straight up out of the chimney.
USGS Diagram Explaining Cause of Steam Eruptions

The factsheet notes that “Many of Kilauea’s pre-1924 explosive eruptions that produced significant ash deposits probably happened when the volcano’s summit crater was so deep that its floor was below the water table, letting ground water seep in to form a lake.

If I’m understanding correctly, they’re saying that bigger explosions may happen when there’s a lake of water, i.e. more fuel to create steam.

Edited to add: HVO’s page outlining the history of Kilauea Caldera also goes into past explosive episodes. Final paragraph:

“Having pieced together the recent geologic past of Kīlauea, scientists conclude that the volcano will eventually return to a long period of mostly explosive activity, just as it did around 1500 CE. This future explosive period will probably accompany a significant decrease in the magma supply rate and be initiated by collapse of a new caldera to the depth of the water table, which today is about 615 m (2015 ft) below the present high point on the caldera rim. For now, effusive eruptions dominate Kīlauea.”

Note: that’s a new caldera, the much larger basin containing Halema’uma’u crater within it, and the vent that’s erupting ash explosions right now was a small lava lake covering only part of the floor of Halema’uma’u. Orders of magnitude different in terms of size. Also, changing the location of the active vent doesn’t mean the magma supply inside is dropping.

May 9-10: USGS Warns of Possible Steam Explosions

Attention shifted back to the summit on May 9, when a 3.1 earthquake set off a rockfall that agitated the lava lake and sent up a 6000-foot poof of ash (video clip National Parks site):

Rockfall into Halema’uma’u lava lake sends up plume of ash, 8:27 May 9.

Rockfalls caused poofs of ash like this even back when the lava lake was full, but that was more than usual. (See also USGS video from May 7, when lava lake was still visible, showing how falling rocks agitate it).

However, that was just a teaser. The big news was the dropping lava lake…

…prompted HVO to issue its first warning about steam explosions if the lava dropped below the water table.

Hawaii Volcanoes National Park closed Friday May 11 as a precaution, since the lava lake was projected to reach the water table sometime that day. For the next few days it continued to send up a white plume of steam and/or ash clouds when rocks from the sides of the chimney fell in:

[USGS] May 11, 9:12 AM: second ash explosion
On steam (phreatic) explosions:

Continue reading May 9-10: USGS Warns of Possible Steam Explosions

May 4: USGS Scientist Explains First 24 Hours of Eruption

HVO Scientist-in-Charge Tina Neal gave an EXCELLENT evening briefing on the first 24 hours of the Leilani Estates Eruption, explaining very clearly what was happening and why.

[Big Island Video News, overlaid with video from Mick Kalber flyover]

Powerpoint slide summary of TALK:
  • 6 fissures in first 24 hours — more are expected
  • No lava flows extending more than tens of yards so far — flows are expected
  • Magma intrusion into LERZ [Lower East Rift Zone] is continuing
  • High levels of sulfur dioxide gas [SO2] near fissures and downwind
  • More Magnitude 5+ earthquakes possible as volcano adjusts to intrusion
Excerpts from this Briefing:

Continue reading May 4: USGS Scientist Explains First 24 Hours of Eruption