July 6: Living With the 1% Possibility of Caldera Collapse

USGS, July 6, 2018. Dawn at Fissure 8. (Full-sized)
Today’s Eruption Summary

The Lower East Rift Zone eruption continues pretty much as usual: Fissure 8 feeding a lava river with occasional short-lived overflows. The main lava channel no longer reaches the ocean, but crusts over a half mile from shore and dives into the lava delta, oozing out at multiple points on the northern side. One especially large “ooze-out” makes a short flow on the north side of the flow field near the last few Kapoho Beach Lot Houses, a few of which are hanging on. Fissure 22 is weakly spattering with a weak flow to its east. Today’s summit explosion occurred at 6:04pm, equivalent of M5.3. Thick fog obscured the livestream view.

July 6, 2018, USGS. Ocean Entry at Kapoho. (Full-sized)

So that’s all routine, if a volcanic eruption can ever be routine. The big news today actually took place last night (see what happens when I finish my posts early?):

July 5 Volcano Community Meeting

Thursday evening, there was an important community meeting in Volcano Village. Mayor Harry Kim, the USGS and Civil Defense outlined the extremely unlikely but potentially life-threatening (to people near the summit) possibility of large-scale caldera collapse. I’ve transcribed the meeting here. BigIslandVideoNews excerpted the crucial 4-minute presentation from HVO’s Tina Neal:

Preceding this meeting was a long-expected document from USGS: Volcanic Hazard at the Summit of Kīlauea UpdateWhile the Kīlauea Summit Earthquakes FAQ explained what is happening, this new update to a May 8th report summarizes what the USGS thinks might happen at the summit before this sequence is over, based on the volcano’s distant past.

During the Q&A session, a resident asked about the odds for the worst-case scenario, a large-scale caldera collapse with explosive activity. Harry Kim took the mike from Tina Neal and said, “Like you, we always like to know percentage odds. And she knows; I asked her that. And I’d like to answer because she said, ‘One percent.'” [Tina went on to explain how they arrive at such probabilities; she wasn’t being flippant.]

Another reassuring quote from the Q&A session:

Don Swanson: “I think that the evidence we have today looks to me as if [the subsidence/collapse] is going to be confined to within the caldera, because the outermost circumferential fractures that have been occurring on the caldera floor have not extended outward in the last 2-3 weeks or so. So to me, that suggests that they may be defining the outermost limit of potential caldera collapse.”

USGS: “The WorldView-3 satellite acquired this view of Kīlauea’s summit on July 3. Despite a few clouds, the area of heaviest fractures in the caldera is clear. Views into the expanding Halema‘uma‘u crater reveal a pit floored by rubble. HVO, on the northwest caldera rim, is labeled.” (Full-sized)

Continue reading July 6: Living With the 1% Possibility of Caldera Collapse

July 5: Lava Takes Aim at Last of Kapoho Beach Lots

July 5, 2018: USGS: “Near the Kapoho Crater, in the area called Four Corners, the lava channel makes a 90-degree bend. After lava exits the bend, it makes a short drop to form a lavafall. A side channel makes a short surface diversion before rejoining the existing channel.” (Full-sized)
Today’s eruption summary

The LERZ eruption continues with minor variations. This morning’s USGS overflight crew observed that Fissure 8’s fountain and lava level in the upper channel appeared to be slightly lower. However, the lava flow rate down at Kapoho Beach Lots —where there were only a few houses left, as of this morning — seems to have picked up slightly.  Meanwhile, overflows spilling out from the constricted turn around Kapoho Crater have nearly reached Beach Rd about 0.2 miles north of Four Corners. Lava continues to enter the ocean along a very broad front, mostly on the northern side of the delta.

July 5, 2018. USGS: “Lava enters the sea along the Kapoho coastline, building a delta that is now over 555 acres in size.” ( full-sized )

Fissure 22 is “sporadically spattering,” and its flow  may have stalled.

At the summit, today’s collapse/explosion occurred at  1:20 PM HST, registering as a magnitude 5.2. Once again, I noticed rockfalls picking up about a minute before the big shake, although it might be coincidence (they’re happening at other times of the day as well):

The Italian Space Agency has posted a new satellite radar image of Kilauea Caldera, showing the ongoing subsidence across much of the crater floor (you may have to view full-sized version for the animation):

USGS: “This animated GIF shows a sequence of radar amplitude images that were acquired by the Agenzia Spaziale Italiana CosmoSkyMed satellite system. The images illustrate changes to the caldera area of Kīlauea Volcano that occurred between May 5 and July 4 at about 6:00 a.m. HST…Over time, expansion of the summit eruptive vent within Halema‘uma‘u crater and the widening of Halema‘uma‘u itself are obvious. Starting in late May, the development of several cracks outside Halema‘uma‘u is clear, and inward slumping of a large portion of the western, southwestern, and northern crater rim begins. Much of this motion appears to be coincident with the small explosions from the summit that have taken place on a near daily basis since early June. The most recent radar scene, from July 4, shows continued motion along cracks over a broader area of the caldera floor, extending east of Halema‘uma‘u (these cracks are the scarps seen in recent photographs from the Keanakākoʻi overlook area).” (Full-sized)

By the way, if anyone else was confused by recent Hawaii Tribune Herald articles that said SO2 levels had climbed tenfold at the summit, I checked with @USGSVolcanoes, who suggested a minor mixup. That increase is occurring down in the Lower East Rift Zone. At the summit, according to Kyle Anderson during today’s media conference call, SO2 levels have dropped to the level they were before the lava lake first appeared.

 

Continue reading July 5: Lava Takes Aim at Last of Kapoho Beach Lots

July 4: Fireworks Every Day In Hawai’i

Today’s entry is going to be a challenge, because my computer chose a holiday to go pau. Arthritis and dodgy vision versus voice dictation and tablet — who will win?

July 4, 2018. USGS: “USGS scientist observes the glow of fissure 8 fountain and channel within Leilani Estates. Steam rises from cracks and hot spots within the tephra deposit surrounding the cone. Frequent observations of the cone and channel are made throughout the day and night to track changes that could lead to signfiicant breakouts beyond the current flow field.” (Full-sized)
Today’s eruption summary

The LERZ eruption continues pretty much as usual, with a few minor embellishments to keep field crews on their toes.

Today’s HVO update noted that Fissure 8 “has been pulsing with more vigorous output in 1-3 minute bursts.” When asked for clarification, USGSVolcanoes replied, “No true indication of change.” F8 continues to send lava downriver to Kapoho, where lava is oozing out along most of the broad front and encroaching on Kapoho Ag and Beach Lots properties.

Fissure 22 continues to spatter intermittently and produce a short, sluggish flow:

Wednesday, July 4, 2018, 5:45 am – Kilauea's east rift zone overflight: Fissure 22 continues to spatter bits of lava…

Posted by Extreme Exposure Fine Art Gallery on Wednesday, July 4, 2018

…and it still looks like a kid’s science experiment. (It’s hard to tell from overhead, but it’s a perfect steep-sided cone.)

Remember how the lava channel clogged up temporarily around the bend at Kapoho Crater yesterday? It’s still having problems:

July 4, 2018. USGS: “The lava channel from fissure 8 jumped its banks near Kapoho Crater where the channel makes a 90 degree bend. The flow within the channel was diverted around a constricted area and joined the channel again “downstream” to the south (left).” (Full-sized )

I lucked out this morning and caught @HotSeatHawaii ‘s sunrise overflight live, which offered a good view this. Part of the lava is going wide instead of making the sharp turn, though it joins back up around the bend. (More photos below.)

Today’s summit collapse/explosion occurred at 10:19 AM HST. The view was fairly clear today, and the rockfalls were spectacular:

Continue reading July 4: Fireworks Every Day In Hawai’i

July 3: Lava Boats Cause Overflows

July 3, 2018. USGS: “Fissure 8 and the upper lava channel, viewed from the early morning helicopter overflight of the lower East Rift Zone. Recent heavy rains have soaked into the still-warm tephra and the moisture rises as steam (right side of lava channel).” (Full-sized)
Today’s Eruption Summary

Kilauea’s double eruption continues with little change, except for a few more spillovers. Fissure 8 is feeding its lava river, which continues to ooze out along a broad front on the northern side of the delta and into Kapoho Beach Lots. Fissure 22 continues to spatter intermittently and send out a less-than-impressive flow.

About a dozen Kapoho homes have succumbed to lava over the past week, and more are expected to go. The National Weather Service also reports that there were about 1,200 lightning strikes between 7am and 2pm yesterday during Monday’s lava-boosted thunderstorm in Lower Puna.

Today’s summit explosion occurred at 2:17am HST, with enough clouds that radar couldn’t find a plume (if any). Just to prove seismometers aren’t stuck, the magnitude registered as 5.1. Seismicity is back up to 20-30 quakes per hour after the lull.

July 3, 2018. USGS: “Inward slumping of Halema‘uma‘u continues in response to ongoing subsidence at Kīlauea Volcano’s summit. This image, taken from a temporary observation post located at Volcano House, shows steep walls on the western side of the crater and sloping piles of rubble from rockfall events.” (Full-sized)

Not to be superstitious or anything,  but geologists need to stop giving Pele ideas. During yesterday’s media conference call, Mike Zoellner said, “They [lava boats] do present a risk, because if the flow of the channel jams them against the side and it contacts the levee, that disrupts the flow of the channel. It could divert either the flow itself or the lava going around the boat out of the channel.”

Sure enough, HVO’s Photo & Video Chronology documented a mini-drama today:

July 3, 2018. USGS: “Evolution of a blocked channel, photo 1. A blockage of rafted material within the lava channel causes lava to flow over its banks near the Kapoho cone. In this section of the lava channel a cold lava flow from the 1960 eruption forms a barrier on the north side, which initially directed the channel to the southeast. A constriction in the channel formed at the bend where chunks of cooled rafted lava were able to accumulate and block the flow.” (Full-sized)
July 3, 2018. USGS: ” Evolution of a blocked channel, image 2: While observing this area of the fissure 8 lava channel near Kapoho cone during the morning overflight, geologists witnesed an “apartment-building-sized” blockage within the channel give way and be pushed down stream by the pressurized lava behind. The dark portion within the red channel is the freed blockage. Lava continues to overflow behind the bend and form a cooled black crust. The more quickly flowing lava at the bend has very little crust.” (Full-sized)

See below for a few more photos of this from the Hawai’i County Fire Department.

Continue reading July 3: Lava Boats Cause Overflows

July 2: Fissure 8 Making Its Own Thunderstorms

Today’s Eruption Summary

No major changes in the past 24 hours, except that the lava channel was full and spilling over its levees in a number of places this morning (as seen in this photo by Bruce Omori). For the most part, they weren’t venturing past the boundaries of earlier flows:

Monday, July 2, 2018, 5:45 am – Kilauea's east rift zone overflight: A number of breaches of the channels can be seen here, as the fresher lava appears more silvery than the older.

Posted by Extreme Exposure Fine Art Gallery on Monday, July 2, 2018

Fissure 8 continues roaring along. With slack tradewinds today, it managed to whip up enough pyrocumulus to set off some localized thunderstorms. Fissure 22 is still spattering and feeding a small flow that’s going nowhere fast. At the ocean end of Fissure 8’s channel, lava is oozing out along a broad part of the lava delta and chewing further into what’s left of Kapoho Beach Lots:

Monday, July 2, 2018, 5:45 am – Kilauea's east rift zone overflight: Homes and property in Kapoho are being consumed by the flow's expanding northern boundary.

Posted by Extreme Exposure Fine Art Gallery on Monday, July 2, 2018

The latest summit explosion occurred at 1:24am HST July 2, the usual M5.3, with an ash plume ~1200 feet high. Immediately before, there were about 20-25 earthquakes an hour (a little less than in recent days) and dropped to 5/hour immediately afterwards (again, a little less).

[Below is a USGS video of the June 30 collapse/explosion as seen from Volcano House, I think, which gives a good view of the rockfalls all along the bluffs of the caldera walls]:

I haven’t mentioned LERZ seismicity in some time,  because it’s been low for weeks. But I notice that section of HVO’s daily Kilauea update was amended starting yesterday. Since May, it’s reported “relatively low seismicity” and “low amplitude background tremor” with “numerous small earthquakes” in the LERZ plus occasional “higher amplitude tremor” near the ocean entry. Now it’s added, “Low amplitude tremor increased slightly on June 29 associated with renewed activity at Fissure 22.”

More Photos from USGS

Continue reading July 2: Fissure 8 Making Its Own Thunderstorms

July 1: Fissure 22 Is Back; Kilauea Caldera Is Sinking

Fissure 8 gushes on unchallenged and unchanged, while Fissure 22 — remember the chief subject of Lavacam?— has started spattering 50-80m and sending out a modest lava flow headed NE along the edge of previous flows.

USGS photo from morning overflight, July 1, 2018. Fissure 8 in the distance, Fissure 22 in the middle ground across from PGV. (Full-sized)

Down at the coast, lava continues to ooze out from under much of the northern part of the delta along a broad front, with “pasty” lava squeezing out in several places along Kapoho Beach Lots.

As of 8:30pm 11pm HST, I’m waiting for confirmation of the next summit collapse/explosion.

Besides Fissure 22 reactivating in earnest, the news today is that new digital elevation maps and satellite images give us a clear view of the subsidence of Kilauea Caldera around Halema’uma’u, which has begun to show in livestream and webcam views lately.

First of all, USGS seismologist Kyle Anderson posted this color-coded slide of caldera ground deformation in his Thursday evening talk:

The colors compare the new June 19, 2018 drone-surveillance digital elevation map with a DEM of the caldera captured in 2009. Presumably the light gray areas within Halema’uma’u don’t correspond to anything on the older map, so can’t be compared. Green patches are earthquakes over the past few days indicating stress. And “300+ ft” marks the last known position of the NPIT GPS sensor before it sank out of radio contact. (Full-sized)

Next, the Italian Space Agency’s trusty Cosmo-Skymed satellite has sent us another radar survey of Kilauea. Even though I’d observed dramatic subsidence of the caldera floor in recent livestream and webcam images, the last frame of this animation made me gasp:

USGS: “This animated GIF shows a sequence of radar amplitude images that were acquired by the Agenzia Spaziale Italiana CosmoSkyMed satellite system. The images illustrate changes to the caldera area of Kīlauea Volcano that occurred between May 5 and June 30 at about 6:00 a.m. HST[…] Over time, expansion of the summit eruptive vent within Halema‘uma‘u crater and the widening of Halema‘uma‘u itself are clear. Starting in late May, the development of several cracks outside Halema‘uma‘u is clear, and inward slumping of a large portion of the western, southwestern, and northern crater rim begins. Much of this motion appears to be coincident with the small explosions from the summit that have taken place on a near daily basis since early June. The most recent radar scene, from June 30, shows the formation of cracks over a broader area of the caldera floor, extending east of Halema‘uma‘u (these cracks are the scarps seen in recent photographs from the Keanakākoʻi overlook area). We expect this slumping to continue as long as the collapse events and overall subsidence persist. (Full-sized)
We are well on our way to a nested caldera, with Halema’uma’u taking up over half the larger caldera floor. I’m hoping those earthquakes indicate where the edge of the new inner caldera will be, but I’m not a geologist. Here’s those scarps they mentioned, posted a few days ago:

USGS: “Comparison of photographs taken on June 13 and 26 from near Keanakāko’i Crater overlook in Hawai’i Volcanoes National Park shows a subsidence scarp that formed as the Kīlauea Crater floor subsided. Scientists estimate the dramatic dropping of the crater floor in this area occurred sometime between June 23 and 26. The view is to the west. Halema‘uma‘u crater is in upper right.” (Full-sized)

Last but not least, the USGS posted this map of the fracturing around Halema’uma’u. Note that the diagram is projected onto a satellite photo of the pre-May caldera, so there’s a ghostly image of the Halema’uma’u we remember in that dark gray area.

USGS: “This map shows major fractures in yellow (as of June 29) on a base image acquired by the WorldView-2 satellite before the current sequence of events began at Kīlauea. The area of major subsidence has expanded east and south, and slightly west, of the main Halema‘uma‘u crater area. The large, red-shaded area east of Halema‘uma‘u is moving down within a scarp-bounded area, as seen in recent photographs of the summit. Some fractures have also formed to the east-northeast of the red-shaded area of accelerated motion, and also on the south caldera rim where parts of the caldera wall have slumped into the rapidly moving caldera floor below. The dark gray-shaded area within the red shaded area shows the region of most significant down dropping and is currently the deepest part of Kīlauea caldera.” (Full-sized)

So there you have it.  Who would’ve thought the draining of the lava lake, which was minuscule compared to the whole summit caldera, would’ve had a domino effect this large?


The rest of this post is a fairly sparse weekend roundup of a few news stories, videos and photos, plus of course the usual science geeking with USGS. Which leaves you time to browse the USGS Thursday evening talk I transcribed today!
Continue reading July 1: Fissure 22 Is Back; Kilauea Caldera Is Sinking

June 30: Kapoho Beach Lots Burning Again

Fissure 8 continues to behave much as it has for the last month or so, looking ever more like a Mordor backdrop:

June 30, 2018: Fissure 8 looking Mordor-like during the USGS morning overflight. (Full-sized)

Today’s official HVO Kilauea update is a copy-and-paste of yesterday’s, apart from this small addition describing the lava delta: “lava is moving beneath the crust and into [the] still-molten interior of earlier flows before it enters the sea in multiple oozeouts.” Like this:

USGS: “Lava was entering the ocean over a broad area this morning. This image shows an active entry area along the northern flow front at Kapoho. View to the south.” (Full-sized)

Unfortunately, some of those “oozeouts” are occurring at the edge of Kapoho Beach Lots as well. At least one home burned today, perhaps more.

Check the Hawaii County Fire Department photos later in this post (or the Bruce Omori photos at the end of the post) to see what the slow-moving expansion into Kapoho Beach Lots looks like right now.

USGS: “View of Kīlauea Volcano’s summit [from Volcano House, I think]. The brown visible dust coming from Halema‘uma‘u is from rockfalls.” (Full-sized)

Kilauea’s summit is changing visibly day by day. Today’s collapse explosion came at 2:51pm, 31 hours after the previous event. Mag 5.3, as usual, with a 500-foot ash-poor plume (captured on livestream). It was somewhat obscured by dust from multiple rockfalls 3 minutes earlier. Here’s a before-and-after:

More USGS Morning Overflight Photos

Continue reading June 30: Kapoho Beach Lots Burning Again

June 29: New Ways to Watch Changes at the Summit

Today’s Eruption Summary

Fissure 8 and the summit explosions continue their status quo. However, for the last few days, the lava flow at Kapoho has been encroaching on new areas on its northern and southern boundaries at the coast.

At least 3 more Kapoho Beach Lot houses have burned on the north side, and the southern edge of the flow is burning vegetation and/or farmland west of Highway 137. I gather these new lateral outbreaks are due to the lava channel crusting over, about half a mile inland from the new coastline (see Wednesday’s thermal map). So instead of pouring straight from the channel into the ocean, lava is fanning out under the crust of the 2-mile-wide lava delta laid down earlier this month, then oozing out the sides.

[USGS drone footage of Fissure 8 from before dawn. They’re using drones for the first time to map flows, look for outbreaks and measure the lava river’s speed.]

At Kilauea’s summit, today’s collapse explosion occurred at 7:51am HST, June 29, with an ash-poor steam plume that rose 500 feet. (Steam?)The energy release dropped slightly to 5.2. I didn’t do a video capture, since the summit was blanketed in morning fog.

The “new news” today is that HVO has added two new views to its Kilauea Webcams page. One I’ve mentioned before, the old “Kilauea East” webcam from HVO’s 1990s website which has annoying reflections but a great view of the subsidence/collapse on the east side of Halema’uma’u Crater:

June 25, 2018 screengrab from “Kilauea East” webcam.

The other is a new heat-sensitive webcam which should make it possible to see “collapse explosions” at night:

Screengrab of Halema’uma’u Thermal webcam at sunset, June 29.

Also, in this week’s “Volcano Watch” newsletter, Hawaiian Volcano Observatory scientists explain the “piston” model they’ve developed to account for the daily collapse explosions at the summit:

(See also the “Kilauea Earthquakes FAQ” they posted earlier this week.)

This is big news. They’ve solved the mystery of the summit explosions! Subject to revision, of course; they’re still untangling the complexities of Kilauea’s current eruption. But the “piston” model accounts for the cyclical pattern they’re seeing better than the “steam explosion” model.

Continue reading June 29: New Ways to Watch Changes at the Summit

June 28: Media Visits Damaged Park, Views Crater

Early morning USGS photo of Fissure 8 on June 28, 2018. (Full-sized)
Today’s eruption summary

Exactly 8 weeks after the Lower East Rift Zone eruption began in Leilani Estates on May 3, Fissure 8 continues to gush unabated. Its fountains are contained within its 55-meter (180 ft) cone, and this morning’s overflight showed no active overflows.

For the past day or so, the lava river has crusted over on the last half mile to the ocean. This has allowed lava seeps, described by Steve Brantley in his Tuesday evening  talk, to creep into still-molten earlier flows on the northern side of the lava delta. This “lava seepage” is oozing into the ocean along a broad front, encroaching  onto what’s left of Kapoho Beach Lots on the northern edge of the flow:

USGS: “View of the ocean entry (lower left) from this morning’s overflight. Lava was entering the ocean across a broad area primarily on the north part of the lava delta. Upslope along the northern margin of the flow field, lava is still oozing from several points in the area of Kapoho Beach Lots. Fissure 8 lava fountain in the upper left. Note southward bend in the lava channel around Kapoho Crater.” (Full-sized)

At Kilauea’s summit, the most recent collapse explosion occurred at 4:49am this morning, sending up an ash-poor plume about 1000 feet, with the energy release of a 5.3 earthquake. The sides of Halema’uma’u continue to collapse inward and downwards, especially during each explosive event.

Increased seismicity in the hours leading up to each explosion, up to 25-35 small earthquakes an hour, is wearing on the nerves of nearby Volcano Village. The USGS is meeting with them tonight to talk about the ongoing earthquakes, and released an excellent FAQ today: Frequently Asked Questions About Kilauea Volcano’s Summit Earthquakes.”

Local News Outlets Given Brief Tour of Summit

The big news today is that the National Park Service and USGS arranged a brief escorted tour for local news media to the rim of Kilauea Caldera, which has been closed to visitors for 49 days. There was also a half hour press briefing.

So today there’s suddenly a lot more videos and views of what the caldera looks like:

In fact, I’m going to put the news media links before the science segment of today’s post. Boldfaced articles include quotes, videos, and/or photos from the media summit tour.

Continue reading June 28: Media Visits Damaged Park, Views Crater

June 27: Farm Animals Airlifted

Prelude

Here’s an excellent 13-minute retrospective of Kilauea’s eruptions from the early 20th century right through June 25, 2018.

Now back to the present.

Today’s Eruption Summary
USGS: “At 10:41 p.m. HST on June 26, after approximately 25 hours of elevated seismicity, a collapse explosion occurred at the summit producing an ash-poor steam plume that rose less than 1,000 ft above the ground surface before drifting to the southwest. The event was captured by an HVO webcam in moonlight (plume in bottom of photo), located in the HVO observation tower.” (Full-sized)

It’s 11:30pm HST, and it looks like today’s “collapse explosion” is going to happen tomorrow. Are the explosion spacing themselves out more now?  Too early to tell. There has been always some variation in their timing, despite the fact that it feels like we’re watching a magmatic equivalent of Old Faithful.

View of Fissure 8 cone and lava channel from USGS morning overflight. (Full-sized)

Meanwhile, Fissure 8 continues exactly what it has for— what, a month now? Fountains contained within its 180-foot spatter cone continue to pour out an 8-mile river of lava. Occasional spillovers near the head of the river usually don’t go past the margin of previous flows in this eruption. Fissure 22 is once again showing “incandescence” and pushing out small, short lava flows.

The ocean entry area fans out across a 1-km stretch of coast, but the bulk of the lava is dumping into the sea from Fissure 8’s main channel. Unfortunately, the northern margin of the lava flow has reactivated, too, pushing further into what’s left of Kapoho Beach Lots community.

USGS on Twitter: “Morning overflight revealed northern margin of flow field at the coast is oozing fresh #lava at several points in the area of #KapohoBeachLots. Small channel overflows feed short #pahoehoe flows.” (Full-sized)

USGS: “Lava continues to enter the sea along the southern Kapoho coastline. Lava enters the ocean primarily through an open channel, but also along a 1-km (0.6 mi) wide area. Also visible in the image (center right) is an area at the northern margin of the flow field that is oozing fresh lava at several points in the area of Kapoho Beach Lots.” (Full-sized)

And that’s about it. Except that even with status quo, there’s some unusual sights and itoday. Such as this literal “Lava boat”:

Continue reading June 27: Farm Animals Airlifted