Tag: pohoiki

July 19: Rockfalls That Look Like Niagara

July 19, 2018. USGS: “Volcanic gases rising from the fissure 8 vent and lava channel feed a pyrocumulonimbus cloud above the tephra cone. Small pits in the tephra deposit (foreground) form when the lava fragments collapse into cracks and void spaces below the surface.” (Full-sized)
Today’s Eruption Summary

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.

July 19, 2018. USGS: “An aerial view looking south, with the fissure 8 lava channel on the west side of Kapoho Crater, visible at left. As it nears the ocean, the channelized lava transitions to a broad ‘a‘ā flow that spreads laterally and toward the coast. The ocean entry plume is barely visible in the far distance (top).” (Full-sized)

Today’s summit collapse event occurred at 4:33 pm.

July 19, 2018. Collapse event tweeted by USGS: “Hereʻs a photograph from the 4:33PM #TypeA collapse event from #Kilauea summit. Rockfalls occurred from near-vertical cliffs around the #caldera and #Halemaumau.” (Full-sized)

The HVO Kīlauea livestream wasn’t too jerky today:

here’s the Northeast Caldera Rim livestream of same event.

July 19 LERZ Lava Flow Map

 

July 19, 2018, 12 pm. USGS LERZ lava flow map. (Full-sized)
HI Dept of Land and Natural Resources
Thursday 1 pm USGS media conference call

Excerpts from BigIslandVideoNews:

Full conference call audio archived here.

From Local News Media
Mick Kalber Overflights

Mick posted yesterday’s June 18 overflight (good views, including that lava flow moving over a still-active but slower flow) and notes as well as today’s:

Here’s the notes/observations/blog post for this morning.

USGS Q&A on Social Media

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.

July 19, 2018. USGS: “his HVO geologist is standing on tephra (airborne lava fragments, such as Pele’s hair) that was erupted from and deposited downwind of the fissure 8 vent. He was there to observe the vent activity and to capture both thermal and video imagery of the pulsations occurring in the near-vent channel. The frame of a water catchment tank cover can be seen in the tephra deposit to the left of the geologist’s camera and tripod (center).” (Full-sized)

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.

July 19, 2018. USGS: “Numerous rockfalls have occurred within Halema‘uma‘u and along Kīlauea’s summit caldera walls today, stirring up existing ash deposits and rock dust, and creating sounds that, at times, could be heard from the northeast rim of the caldera.” (Full-sized)

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

July 19, 2018. USGS: ” An aerial view looking to the west, near the braided section of the fissure 8 lava channel. During this morning’s overflight, the channelized lava was at a lower level than usual, but was still being fed by vigorous outflow from the vent.” (Full-sized)

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.]

July 19, 2018. USGS: “As of this morning, the southern margin of the fissure 8 ocean entry was about 500 m (0.3 mi) from the boat ramp at Isaac Hale Park.” (Full-sized)

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.

From Other Photographers/Social Media

Mahalo to National Geographic for collaborating on a condensed geological essay on the eruption!

Posted by Andrew Richard Hara : Media on Thursday, July 19, 2018

Lava channel crusted over is silvery;

Mono chrome #lavaisland #lavaflow #canonusa

A post shared by John Kapono Carter (@johnkaponocarter) on

Things too obscure to bug USGS about: why is it “littoral” when the Latin word for seashore has only one “t”?  [Checks etymology: ah, yes, it’s a Medieval Latin spelling.)

July 18: One Moving Lava Flow Atop Another?!

July 18, 2018. USGS: “The fissure 8 cone (right) and proximal lava channel were partially obscured by volcanic gas emissions this morning. In concert with surges in the eruptive activity, lava levels were fluctuating over periods of about five minutes. Deposits of tephra (airborne lava fragments, such as Pele’s hair) blanket the foreground area.” (Full-sized)
Today’s Eruption Summary

Fissure 8 surged after last night’s summit collapse and sent brief-lived overflows towards Nohea Street and on both sides of the channel further down. Civil Defense reported an unspecified number of structures lost; Janet Snyder of the Mayor’s office said one in the mandatory evacuation zone of Leilani Estates.

Other fissures remain quiet.

July 18, 2018. USGS: “An increase in lava supply overnight produced several lava channel overflows that threatened homes on Nohea street in the Leilani Estates subdivision; farther downstream, lava overflowed both sides of the channel. By mid-morning, the overflows had stalled (flow shown here). For scale, a person’s leg and boot are just visible on the right center edge of this photo.” (Full-sized)

Past Kapoho Crater, a pulse of a’a made its way to the ocean, overriding the existing channelized flow on the south side of the delta. Ooze-outs continue here and there along the edge of the delta.

July 18, 2018. USGS: “Several lobes of fissure 8 lava are entering the ocean along a broad front, with the southwestern edge of the entry shown here. The southern margin of the lava flow was about 700 m (0.4 mi) from the Pohoiki boat ramp this morning.” (Full-sized)

We’ll have to wait another day to see how summit collapses look from the new Northeast Caldera Rim livestream. Today’s occurred at 1:28 am July 18. They seem to be spaced farther out, but it still registered as a M5.3.

July 18 Lower East Rift Zone Map
July 18, 2018. USGS: “Map as of 10:00 a.m. HST, July 18, 2018. The south ocean entry area was obscured by laze (acidic steam plume), so the southern boundary of the lava flow is approximate on this map.” (Full-sized)

And the smoke from a fire on the saddle area of Mauna Loa this evening is NOT a volcanic eruption.

Continue reading July 18: One Moving Lava Flow Atop Another?!

July 17: New and Old Views of Halema’uma’u

July 17, 2018. USGS: “During this morning’s overflight, USGS scientists captured this image of sunrise above Kīlauea’s lower East Rift Zone. Fissure 8 continues to feed a channelized lava flow that reaches the ocean, forming a large plume at the coast (upper right).” (Full-sized)
Today’s Eruption Summary

And we’re back to routine, except that Fissure 8’s providing a minor puzzle to keep HVO busy. Yesterday it didn’t exhibit the surge behavior that’s been typical after summit collapses for the week or so. Today, nowhere near the time of a collapse event, “surging was noted at the Fissure 8 cone during the [morning] overflight but had stopped by the time ground crews arrived to verify it.” Otherwise, the channel’s lava level was low this morning. No other were fissures active.

July 17, 2018. USGS: ” During their overflight, scientists used a telephoto lens to photograph the surface of the fissure 8 lava channel. Incandescent lava is visible through pieces of darker crust that forms as the flow surface cools. Note the apparent symmetry on either side of the channel center, where lava flows more quickly than it does along the channel margins—a visual representation of flow velocity across the channel width.” (Full-sized)

Both the strong southern ocean entry and weak “ooze-outs” north along the edge of the lava delta continue. Onshore, the southern margin of the flow front was reported to be half a mile from the Pohoiki boat ramp this morning. Unfortunately, that flow edge has stalled but not stopped, and a DLNR official warned Isaac Hale Park is still within its sights.

July 17, 2018. USGS: “South margin of the fissure 8 lava flow ocean entry. As of this morning, the flow was about 750 m (just under 0.5 mi) from the Pohoiki boat ramp.” (Full-sized)

We’re still awaiting the next summit collapse, which looks like it’s going to thwart HVO’s new “Northeast Caldera Rim” livestream by happening at night.

Speaking of the northeast rim, here’s the July 12 collapse event with sound from that vantage point:

Also out today is this impressive new Kīlauea Digital Elevation Model.

The split-second info card at the end says the floor of Halemaʻumaʻu Crater has dropped 450 m (1480 ft). Prior to the current eruption, it was 85 m (~280 feet) deep. So it’s about 1760 feet deep now. (World Trade Center One is 1776.)

Continue reading July 17: New and Old Views of Halema’uma’u

July 16: Lava Boat Tourists Injured

July 16, 2018. USGS: “The active ocean entry along the southernmost margin of the fissure 8 flow is a hazardous area. The interaction of lava and seawater creates “laze,” a corrosive steam plume laced with hydrochloric acid and fine volcanic glass particles that is blown downwind and can irritate the skin, eyes, and lungs. Lava flows entering the ocean can also result in explosive interactions, littoral explosions, that can hurl fragments of molten lava and rocky debris hundreds of meters (yards) inland and seaward.” (Full-sized)
Today’s Eruption Summary

The big news today was a lava tour boat getting pelted by lava chunks from an ocean entry explosion, resulting in burns, bruises, and one broken leg. Next to that, the science of this eruption seems a bit trivial. But this blog is primarily oriented towards the latter, so let’s get volcanology news out of the way first.

The Italian Space Agency released a new CosmoSkyMed radar scan of Kīlauea’s summit. Let’s hope this really is the new northern extent of Halemaʻumaʻu:

May 5-July 16, 2018. USGS: “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 16, 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.” (Full-sized)

This morning, over 24 hours after the previous summit collapse, the lava channel below Fissure 8 was full but not overflowing. Even after today’s 11:42am summit collapse, there was no observed surge— “Nothing notable in the way of overflows.” Last night’s field crews heard Fissure 22 grumbling to itself, but saw no visible signs of renewed activity.

According to Civil Defense this afternoon, the southern edge of the main lava flow has stalled 1 km from Isaac Hale Park / Pohoiki boat ramp. Just north of there, the new ocean entry at Ahalanui is vigorous and dangerous. That’s where @hotseathawaii filmed an offshore explosion four days ago. There were more explosions this morning, “with at least one being quite strong” (USGS).

(The summit collapse was M 5.3 again. The livestream is still ailing, but even so it captured rockfalls, camera shake, and the earthquake’s progression from far to near in the field of view.)

July 16 Map of Active Lava Flows

Lava delta is up to 690 acres, by the way. “Tiny no-longer-island” is next to the c in “former coastline.”

USGS map of LERZ lava flows as of July 15, 2018, 1 pm HST. Yes, the tiny no-longer-an-island is visible in the full-sized image.

Continue reading July 16: Lava Boat Tourists Injured

July 15: Tiny Island Is Now Tiny Peninsula

July 15, 2018. USGS: ” View of fissure 8 looking uprift toward the west. The open lava channel in upper right leads to the ocean; when the photo was taken this early morning, nearly all of the lava erupting from fissure 8 was in the channel. Some lava was spilling eastward to form a slowly advancing flow (middle foreground) atop earlier lava flows. This flow stalled within hours.” (Full-sized)
Today’s Eruption Summary

Kilauea’s double eruption continues as usual. Fissure 8’s lava river is still sending lava mostly to the southern ocean entry near Ahalanui, following the diverted channel on the west side of Kapoho Crater. The southern margin of the lava flow along the coast has slowed its southward advance, possibly giving Pohoiki/Isaac Hale Park a respite. At 7pm HST, HVO said it was “around half a mile away.”

July 15, 2018. USGS: ” Laze plume rises where lava pours into the sea on the south margin of the fissure 8 flow. This southern boundary did not change location appreciably in the past day, remaining about 900 m (0.56 mi) from the boat ramp at Isaac Hale Park.” (Full-sized)

The tiny island that formed Friday is now a tiny peninsula, joined to shore by a neck of lava or possibly just black sand. Lava continues to ooze into the ocean here and there along the broad front of 6 km (3.7mi) lava delta. Recent HVO Kilauea status alerts have warned that this delta has built out 0.5 miles from the former coastline, and is resting on “unconsolidated lava fragments and sand,” which can give way.

Following this morning’s 3:26 am collapse event (M5.2) at Kilauea’s summit, a pulse of lava came down the rift zone to Fissure 8. This caused an early-morning, temporary overflow to the ESE which did not extend beyond the boundaries of earlier flows. (This spillover was very visible during a 6:30am @hotseathawaii livestream overflight). No other vents show any activity.

USGS: “View of Halema‘uma‘u taken today (July 15) from the south side of the caldera near the KEANAKEKOI Overlook.” (Full-sized)

And a reminder of what it used to be like…

Continue reading July 15: Tiny Island Is Now Tiny Peninsula

July 14: Aloha to Pohoiki

July 14, 2018. USGS: ” Early morning view of fissure 8 and lava channel looking toward the east. Laze plume from the ocean entry is visible in distance (left of the fissure 8 plume). Geologists did not observe activity from any of the other fissures during this morning’s overflight.” (Full-sized)
Today’s Eruption Summary

The Lower East Rift Zone eruption has settled back into a routine. Unfortunately, that routine includes the far end of Fissure 8’s lava flow crawling south along the coast, eating landmarks in its path. Isaac Hale Park/Pohoiki boat ramp (see flow map) is next in line. The morning USGS overflight reported that the flow front was about 1km away.

Friday evening, July 13, 2018, 6:00 pm – Kilauea's east rift zone overflight: Lava continues to pour into the sea at…

Posted by Extreme Exposure Fine Art Gallery on Saturday, July 14, 2018

That little island is still there this morning.

Fissure 8 continues to erupt into its perched channel, with its volume surging after yesterday’s 7:08pm summit collapse (Mag 5.3) and returning to lower levels by morning. That pulse caused a brief overflow on the east/southeast of the channel a short way downstream from the vent, but it stayed on the apron of previous flows.

The channelized a’a flow west of Kapoho Crater continues to be the main conduit to the ocean and to the active flow expanding southwards along the shore. North of this, lava continues to “ooze out” at various points along the June-early July flow front, whose length now totals 6km  (3.7 miles).

July 14, 2018. USGS: “White laze plumes mark locations where lava enters the ocean over a broad area. An open lava channel flows into the ocean at the southern-most plume (middle) near the southern flow margin. The boat ramp at Pohoiki is about 940 m (0.58 mi) farther south of the flow margin. View is toward the west-southwest.” (Full-sized)

While there’s no sign of activity at any fissures besides 8, the tiny island that popped up just offshore of Kapoho yesterday is still there for now.

Continue reading July 14: Aloha to Pohoiki

July 12: USGS Conference Call

There was a lot of good info in the Thursday conference call with members of the media. BigIslandVideoNews posted a recording of most of it:

Full audio archived here.

  • Leslie Gordon, USGS Public Affairs Officer
  • Matthew Foster, meteorologist, NWS
  • Jessica Ferracane, NPS, HVNP Public Affairs
  • Janet Babb, geologist, HVO/USGS
  • Mike Zoellner, geologist, Center for the Study of Active Volcanoes, UHI
Transcript – July 11 Eruption Update

Janet Babb, USGS:  On the Lower East Rift Zone, Fissure 8 continues to erupt, and overnight the channelized flow that was diverted from the main channel that went west of Kapoho Crater advanced to the ocean, and, unfortunately, in its path, it destroyed the Kua O Ko La Charter School and the Ahalanui Beach Park area. And there’s now a new, very robust ocean entry plume near the Ahalanui Beach Park area. So in all, the flow front at the ocean now is about 3.7 miles wide.

In this morning’s overflight, there were no other fissures that appeared to be active.

At the summit, following yesterday’s early morning collapse/explosion that released energy equivalent to a magnitude 5.3 earthquake, the earthquakes have resumed— there was a period of quiet, but the earthquakes have resumed and currently the summit area is experiencing about 25-30 earthquakes per hour. This pattern is expected to continue.

As far as gas emissions at the summit, the gas emissions remain low, and on the Lower East Rift Zone, the gas emissions remain high. And with that, of course, the problems with vog continue with those high emissions.

Continue reading July 12: USGS Conference Call