While no glow or incandescence was reported within Fissure 8’s cone for most of the week, Saturday 9/1 showed a few life signs remain in the LERZ: weak spattering from one spot, and in the evening new lava came out to cover most of the crater floor. But its sides have been slumping and falling in, as have the levees of the now solidified lava channel. While Fissure 8 and some of the surrounding vents continue to steam and fume, SO2 emissions remain low there and at the summit.
No active ocean entries have been seen for the past few days, suggesting that all the residual lava from Fissure 8 has stagnated or drained out.
This week has been a time of repair and taking stock. USGS geologists have been replacing lost or damaged monitoring stations (including the UWE tiltmeter, back on HVO’s deformation page). The drone crews have been out after Hurricane Lane came through to take new detailed aerial surveys of Kilauea’s summit (August 30 video) and Fissure 8 (August 21 video).
They also posted an updated timelapse video of HVO’s panorama cam of Halema’uma’u from April 14 through August 20:
Today’s summit collapse came at 11:55 am HST, energy equivalent of an M 5.4. Once again there was a cluster of high M3 foreshocks in the ten minutes or so beforehand, so that there was already some suspended dust from rockfalls.
Northeast Rim livestream cam was stuttering today, but still dramatic.
Also note that HVO’s Fissure 8 webcam was damaged by a brushfire Tuesday and ceased working. In fact, right now it’s stuck on the last photo it took.
While checking on the main webcams page, I caught a lovely time of the evening up at the summit. From the ones that are working:
And speaking of photos, I took a night off, and come back to find HVO posted a ton of good photos! Which I shall mirror here so they’re easier to find after they’ve “fallen off” that Photo & Chronology page.
Most importantly, a new frame from the Cosmo-Skymed satellite radar animation:
Accompanying text with this animation: “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 August 1, shows continued motion along cracks over a broader area of the caldera floor, extending east of Halema‘uma‘u. We expect this slumping to continue as long as the collapse events and overall subsidence persist.”
89 days. That’s how long it’s been since the first fissure started spattering lava in Leilani Estates. Which is one day longer than the 1955 Kapoho eruption, which had been the longest LERZ eruption since records started being kept.
Today’s Eruption Summary
LERZ erupton as per usual. There’s “ooze-outs” of lava on the flow margin, but further inland from Pohoiki. Today’s M5.3 summit collapse was at 7:59 am, when the crater was steaming in the cool morning air.
From HVO, the livestream caught the pressure wave passing through the cloud:
From the NE Caldera Rim livestream, ground shaking and rockfalls were more visible:
Eruption continues as usual with three minor things to note. First: “fuming” on the southwestern margin of the flow near Pohoiki could mean possible breakouts, according to today’s HVO Kilauea status update.
Same source also says that, rather unusually, a 4.1 earthquake at 10:02 pm was felt all the way to Hilo, far more widely than the stronger summit collapse events, possibly because it was at a depth of 7 miles.
And finally, Tuesday will mark the 89th day of the eruption, surpassing the length of the 1955 Kapoho eruption which had previously held the record for the longest LERZ eruption since westerners arrived and began keeping records.
I tweeted him a question about “Halema’uma’u Caldera,” which he seems to be using instead of “Kīlauea caldera.” I know Halemaʻumaʻu crater has expanded so much it could be classified as a caldera now, but so far HVO scientists have resisted doing so, to avoid confusion with the larger, older caldera.
July 30 HCFD Overflight Photos
HCFD’s July 30 album is up on Flickr. Just 12 photos plus the video clip at the top of this post. Including the clearest views we’ve seen of Isaac Hale Park in some time, since the laze plume wasn’t in the way:
Here’s a few USGS photos from today plus the LERZ map, and overflight video and photos from Mick and Bruce:
Before and after: a new aerial photo of HVO on the rim of Kīlauea Caldera shows how greatly Halemaʻumaʻu has changed. For comparison, I found this 2008 photo in the USGS archives:
And here’s today’s overflight photo, from farther away.
The scientists of HVO had to abandon their 100-year-old observatory on the caldera rim mid-May. During the summer session, the University of Hilo was able to provide them with plenty of space for a temporary HQ. With fall term around the corner, HVO has leased part of the U.S. Customs Building in Hilo while they seek a more permanent solution. Because if and when the summit stabilizes, the old observatory will have to be rebuilt, or at the very least, will require massive repairs.
Speaking of the summit, today’s collapse event was at 12:10 pm, energy equivalent of M5.4. I captured the rockfalls 3-4 minutes before, as well as the actual summit collapse:
The clock on the Northeast Caldera Rim livestream is about a minute fast, but it’s so tiny you can’t see it anyway. The actual collapse starts about 1:30 into this video:
No changes on the Lower East Rift Zone eruption today.
Here’s the other HVO images for July 29 (as usual, I’m mirroring them because the HVO “Photo and Video Chronology” page only shows the 20 most recent entries, making images older than two weeks somewhat inaccessible.)
Three months ago today, shortly before 5 pm on May 3, lava began to erupt from one of several cracks that had opened in Leilani Estates in the Lower Puna district of the Big Island of Hawai’i. This followed several days of earthquakes indicating magma moving downrift from Puʻu ʻŌʻō, after its floor collapsed and its lava drained away overnight on April 30.
At first, the fissures spattered and sputtered, with most of the lava falling on both sides of the vents and building up ramparts (walls). Individual fissures erupted for several hours at a time, then died out. Some restarted, others simply steamed. A few sent out sluggish lava flows, claiming a few houses.
On May 19, the eruption began in earnest. Most of the old, stale lava stored in the rift zone since the 1955 and 1960 eruptions had been pushed out, and fresh, hot, runny lava from Puʻu ʻŌʻō began pouring out of vents, sending the first lava flows down to the sea (See the Honolulu CivilBeat livestream from that day, timestamp 6:03). Lava reached the ocean before dawn on May 20.
While Fissure 8 had originally opened on May 5, it was just one of many attempts for all that magma coming down the rift zone to find the most convenient exit. (Magma can reshape its own plumbing, just as we’ve seen lava do on the surface.) Fissure 8 reactivated again on May 28, and within a few days became the dominant vent for this eruption. Its lava flow reached Kapoho Bay the evening of June 3, and had covered the bay within 36 hours.
All that magma exiting the summit caused the lava lake at the summit to drain away, then Halemaʻumaʻu fell into it and started enlarging, and eventually much of the floor of Kīlauea caldera began to subside as well. The collapses were explosive at first, then, after the lava lake’s conduit had been thoroughly blocked by rubble, the collapses settled into a regular pattern.
So here we are. The LERZ eruption has added nearly 800 acres to the island, covering lower Puna with 34.0 square kilometers (13.1 square miles) of lava. We’ve almost come to take for granted this extraordinary eruption, which has dramatically reshaped the summit of Kīlauea and produced more lava in 3 months than Puʻu ʻŌʻō did in 35 years.
Today’s Eruption Summary
HVO’s volcanologists have told us that eruptions like this wax and wane— Puʻu ʻŌʻō certainly did, sometimes pausing for weeks— and that part of what makes Fissure 8 extraordinary is that it’s sustained such a high volume of lava effusion for so long. Today, it’s finally showed signs of weakening— maybe? The USGS reported that its lava flow seemed sluggish and that lava levels are down in the lower part of the channel. The flow margin remains stalled a mere tenth of a mile from Pohoiki’s boat ramp.
Today’s summit collapse event at 6:41 am was upgraded to 5.6 a 5.3, as usual. The USGS apologized for calculations errors for the past 3 days
Since I was out and missed it on livestream, I’m very glad HVO captured it. Here’s yet another trick from Pele’s repertoire:
There’s a lot to look at here. From USGS caption:
“In this video, watch as today’s event unfolds from the perspective of HVO’s live-stream camera. At 6:41:08 (time stamp at upper left), a small tree along the right margin of the video begins to sway. At 6:41:10, a pressure wave passes through the steam plume in the crater, and light is reflected back to the camera (highlights the passage of the expanding sound energy through the air.) At 6:41:11, a rockfall begins on the South Sulphur Banks, a distant light-colored scarp on the left.”
Field crews reported no surge at Fissure 8 following today’s summit collapse.
I notice the latest HVO Kilauea report says Fissure 8’s cone is down to 50 m, “or 55 yards.” It’s definitely crumbled or eroded— that may be responsible for some of the lava boats— but I’m never sure whether they’re measuring from the original ground level or the lava on which it sits. At any rate, the fountaining is lower, too, since it’s not rising above the lip of the cone.
Down at the ocean entry, the main channel is still dumping into the sea from multiple toes near former Ahalanui.
I’m impressed HCFD was able to catch a glimpse under the thick, low laze plume, which was obstructing the view during @HotSeatHawaii’s overflight, which looked about like this (in fact the USGS helicopter was down below them):
“Ooze-outs” are occurring along the west side of the active flow south Kapoho Crater, all the way down to the ocean (where it is threatening Isaac Hale).
Other news that slipped under the radar: HCFD took a swing by the summit yesterday! It was very dusty and hazy, but the new shape of Halemaʻumaʻu is becoming clear:
Look for Crater Rim Drive at lower left around 0:30, falling into the crater where it used to lead to the parking lot; HVO is really hard to glimpse at upper right.
There were several more photos, giving us a little more perspective on the whole of Kīlauea Caldera as it is now:
Status quo. Fissure 8’s lava river continues inexorably to the Ahalanui Beach area. At the coast, the flow has nearly stalled in its southern expansion, but according to Civil Defense has crept within ¼ mile of Pohoiki boat ramp.
July 21, 2018. USGS: “This aerial view, looking to the southwest, shows the most vigorous ocean entry of the fissure 8 flow, which is located a few hundred meters (yards) northeast of the southern flow margin.” (Full-sized)North of the main ocean entry, a few small pahoehoe lobes are still dribbling into the sea along the rest of the delta.
Today’s summit collapse event occurred at 9:43 am, registering as M5.4 for a change. It was preceded by widespread rockfalls about 3 minutes earlier, which I included in the video capture (jittery livestream signal notwithstanding):
As per usual. Fissure 8 continues to feed the lava channel down to the ocean, where the southern margin of the flow was 500 m from Isaac Hale Park this morning. Lava levels in the channel this morning were low, with the previous collapse event coming at 1:28 am the day before.
Today’s summit collapse event occurred at 4:33 pm.
Q: [Is Cape Kumakahi still the easternmost point of the island?] USGS: The area off Kapoho has a paltry supply of lava now – unless significant lava returns, the eastward advancement may cease.
Q: [Has there been any change in temperature of lava, now that it’s crusting over and/or not a fluid channel all the way to the ocean? Any sign eruption is ending?] USGS: No, the temperature remains the same. Other factors are probably responsible for the crusting – blockages, flow velocity, precipitation, etc. Sometimes the channels remain fluid, and sometimes the surface can crust over – but that doesn’t mean there isn’t lava moving beneath the crust… No, no signs that the eruption is ending yet.
Q: [Someone asking about webcams and livestreams] USGS: We weren’t able to adjust the bandwidth on the cam from HVO, but we did add the stream from the northeast caldera, which uses a different (and still challenged) connection.
Q: [Cinder cone is 120 feet now? Was 180; has it collapsed?] USGS: Some settling has occurred, and some of the more precarious bits have probably fallen in or down the slopes. [Same basic question, different day] USGS: Yes it has succumbed to thermal erosion, collapse, and settling. There have been no sustained fountains depositing material on its outer slopes for several weeks, so there has been no additional accumulation of tephra.
Vladimir Vysotsky on FB: USGS Volcanoes: you keep characterizing this as a “perched channel”. I wonder if that is how lava tubes form – a channel builds the foundation and walls around itself, then crusts over while still flowing inside, and eventually forms a tube when the lava finally drains. Is that a correct assumption?
USGS Volcanoes: That is a very accurate description of lava tube formation! ][…] Hereʻs a video from Hawai’i Volcanoes National Park describing what you d[id] with video footage to accompany for visual reference. https://www.nps.gov/media/video/view.htm...
Q: [Is Fissure 8 how Diamond Head formed?] USGS: – Diamond Head is a tuff cone that erupted through water. It is also considered “rejuvenation stage” volcanism. The eruption that formed it occurred after the Koʻolau Volcano (from where it erupted) had been dormant for about 2 million years! http://volcano.oregonstate.edu/post-erosional-rejuvenation
Q: [How long will this go? How will it end? Does a lava flow normally start slowing down and then stop?] USGS: This could go on for any number of days, honestly. Typically these things don’t just turn off and stay turned off. We expect that activity in Fissure 8 will wane, then stop and start again (perhaps at other fissures). However, the eruption won’t stop all together until the pressure driving the magma out of the ground has been relieved.
Q: [How deep is lava channel?] USGS: We have tried to calculate depths based upon lava-flow observations within the channel and known depths of dormant channels on other locations in the Hawaiian islands. The channel is meters in depth, but likely not more than 10. Depth varies throughout its length as well.
[In discussion that Fissure 8 is not a volcano— it’s a vent on Kilauea’s flank just like Puʻu ʻŌʻō was, with magma being piped down from Kīlauea’s magma storage system— someone brought up Lō‘ihi, which IS a new volcano (or seamount) off SE coast of Big Island, still underwater.]
Q: [Is the summit caldera sitting on the magma chamber?] USGS: The subsidence area within the caldera essentially overlies the area of the shallow magma storage region that fed the lava lake in Halemaʻumaʻu. So, yes. Q: [Could the floor collapse into the chamber? What would happen then?] USGS: Technically speaking, the floor, and everything that was between it and the top of the chamber, is collapsing into it. Youʻre seeing the outcome – pressure drops and collapse events that manifest as M5.3 earthquakes.