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.)
Note the light green mostly-treeless area in background at left, and then zoom in to find museum & observatory on rim at right. Then compare with:
April 13, 2018
Today’s Eruption Summary
Summit collapse event at 2:37 am HST, July 28, 2018. Energy release equivalent to M5.4. Minor overflows on Fissure 8’s channel reported a few hours afterwards. At the coast, the SW edge of the flow remains stalled 175 m from Pohoiki boat ramp, with ocean entry a few hundred meters to its east.
Also, notwithstanding longer intervals between recent summit collapses and a few days where the lava channel seemed lower, HVO doesn’t see any strong indications the eruption is weakening:
We can't say for sure, but we don't think so. We've had long intervals between Type A events in the past, and the channel today appears to be as active as it has been in past days, with overflows on existing lava in some places.
Even though I finished my July 26 post last night at 1 am my time, HVO posted a few more photos after that. They show Fissure 8 pulsing, varying in lava output, not just due to summit collapses but simply as natural fluctuations.
Caption: Pulses of lava from the fissure 8 vent sometimes occur every few minutes. These photographs, taken over a period of about 4 minutes, show the changes that occur during these pulses. Initially, lava within the channel is almost out of sight. A pulse in the system then creates a banked lava flow that throws spatter (fragments of molten lava) onto the channel margin. After the third photo was taken, the lava level again decreased to nearly out of sight.
(I often compare volcanic activity to weather— it’s essentially geological weather, with currents and flow and updrafts from deep within the Earth, only the medium is solid and molten rock rather than air and water. When people are asking for volcanic forecasts, they’re asking for weather forecasts, and should expect the same kinds of variability as rainstorms.)
And here’s a night view they posted in the wee hours of this morning (Jul 27):
And while I’m at it, here’s the photos for the afternoon of July 27. HVO might post more later tonight.
USGS/HVO Deputy Scientist-in-Charge Steve Brantley has been giving weekly 10-minute slideshows at Tuesday evening Pahoa Community Meetings. Here’s last Tuesday’s.
Good evening. Thank you for coming out tonight. I have just a short presentation to provide for you this evening, and I invite you to come back to the back of the room at the end of the meeting. I have copies of the report that we put out on Thursday of last week, so you’re welcome to take a copy. Please, one per household. And I’ll draw attention to— the centerpiece of that report is a map. And I have a copy of the map back there that we can talk about if you’d like.
So the activity this past week has not changed significantly, either at Fissure 8 or along the lava channel or at the summit. The summit keeps dropping during these episodic earthquakes, where parts of the crater floor drop 2-2 ½ meters, 7-8 feet at a time, and also overall slow subsidence.
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.
As we approach the 3-month mark— or pass it, since Puʻu ʻŌʻō’s floor collapsed 3 months ago this past Monday— Kīlauea’s 2018 eruption continues with no significant changes. During the USGS morning overflight, the lava’s southwestern margin was holding at less than a tenth of a mile from Pohoiki boat ramp. The vigorous ocean entry continues a few hundred yards to the east. No surges in lava output have been reported at Fissure 8 since Tuesday’s 6:41 am summit collapse.
A deceptive moment of tranquility at the new, extensively remodeled summit:
Here’s HVO’s Steve Brantley giving the weekly eruption update at last night’s Pahoa community meeting (I’ll be transcribing it tomorrow or Friday).
He explains that complicated “lavashed” map released earlier this week, which predicts where lava is most likely to go if there’s a breakout along particular stretches of Fissure 8’s lava channel. This is an aid to residents living in neighboring areas not affected by lava now, but who are worried about what might happen if the flow diverts.
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:
Fissure 8 exhibited surge behavior afterwards. Overnight, drone crews observed minor overflows just northwest of Kapoho Cone, most of which were confined to the existing flow field and/or stopped before traveling far enough to threaten structures.
The main ocean entry and southern margin of the flow haven’t moved much in the past few days. However, USGS reports “a new lobe has started from the southern lobe and is active along its southwestern margin, slowly heading towards the ocean.” Today’s 1 pm map clarifies the new lobe’s location:
Ikaika Marzo, a lava tour boat operator who stays a sensible distance from shore, reportedly saw lava is in Isaac Hale Park, within 50 m of Pohoiki boat ramp at 7:15 this evening.
No summit collapse today, unless the pattern changes; the next one ought to occur tomorrow morning.
Here’s highlights of the USGS Media Conference Call from this afternoon: