Hawaiian names for Months by island
And I have no idea where that tangent originated...random bits banging around in brain...
So. A question was asked in Comments a couple days ago, wondering first, what a caldera is, then, how big can it (Kīlaueaʻs) get.
The reader found a great explanation in Wikipedia. Briefly, a caldera is a BIG crater, more than a mile in diameter, formed by collapse. Kinda like a giant sinkhole. Giant. Calderas here form because a lot of magma is withdrawn relatively quickly from beneath the summit, leaving voids into which the ground above collapses. Kīlauea and Maunaloa have the best (and only) topographically defined calderas on Hawaiʻi.
Magma withdraws during voluminous eruptions or intrusions on a rift zone ma kai (toward the sea) of the summit. The collapsing summit is defined by faults, in this case, vertical caldera-bounding faults that ring the summit. The walls of Kaluapele are those faults. The floor drops, creating a cliff. Hope thatʻs clear...
We are, if youʻve been tuned in, watching pali (cliffs) on the caldera floor develop before our very eyes. And some think...How can??? So....pūʻiwa! And yes, I know I use that word a lot (thanks pj), but share another I can use and I shall. A stupefaction on account of wonder!
First, a relatively simple and colorful closeup of part of a map I posted a couple days ago:
The Topographic Caldera, the one clearly defined by those bounding pali, is the oblongish area, in which sits Halemaʻumaʻu. The Structural Caldera is defined by the outermost bounding faults. Those, on the map above are depicted as black lines with a back dot, a ball, on one side. The ball indicates the side that is lower or has dropped down.
If you look real good, Highway 11 at the entrance to the park is barely inside caldera bounding faults (CBF). The pali there is named ʻŌlapalapa (full of ravines, projections, cornices, ridges), and is the area where the Highway cracked several weeks ago. The CBF forms the east edge of Kīlauea Iki, and crosses the Chain of Craters Road just ma uka of Puhimau crater. And you can also see the CBFs to the west, or left, of Kaluapele, on the Maunaloa-side of Highway 11.
All of the subsidence / collapse / sinking weʻre seeing now is taking place inside the Topographic Caldera. As far as I know, by looking at posted photos, webcam images, etc, there has been no subsidence along the outermost CBFs. Too, the pics weʻve seen of damaged roads and trails in the park are damaged in areas of fill. Gravel was brought in to even out cracks and low places, and the constant shaking has caused the fill to settle and move.
How big can the caldera get? Iʻd guess not much bigger than the Topographic Caldera we see. Over thousands of years, Kīlauea has seen major transformations: calderas form, fill, form again, eruptive centers (vents) are here, then there. Itʻs an extremely dynamic landscape. Evolving over thousands of years.
If you look closely at the image above, from the KEcam, the numerous light-colored tan areas on the pali surrounding Kaluapele are recent big rockfalls. One of the reasons the park remains closed. Walls are indeed Slip Sliding Away....as shown on a VERY cool video (thanks, am), with sound, of the cacophony, maybe sounding like kaikoʻo (raging surf), as mentioned in Hulihia chants:
July 12: The ocean rages
And below, from this morning, our Last 20 ʻōlaʻi. And you can trace the CBF through the forest - the dark line at the lower right, from Kīlauea Iki down toward Puhimau (ever smoking). That blotch of tan and white below Puhimau is the Puhimau hot spot, where a shallow intrusion of magma many decades ago has warmed the ground, killed all the trees, and creates ever smoking steams (māhu).
And below, our next Pūʻiwa Inducing Moment, TryLook!!!! Keen eyes familiar with the terrain can pick out the Halemaʻumaʻu Trail across the caldera floor. Part of the trail now lies on the down-dropped kaulu (ledge) east of Halemaʻumaʻu. Itʻs that faint ash-covered white line. The floor of Halemaʻumaʻu is 1,500 feet lower than it was on May 1, 2018...
July 13, 2018 Animated DEM of Kaluapele
Digital Elevation Model, assembled with data gathered from helicopter, then the DEM was animated. Dizzying!!!
And yes, at Keahialaka, Pele continues. Another overflow of kahawai pele, perhaps initiated (or not) by our M5.3 exploquake at 128a this morning. Almost managed to sleep through it. And I still say the precursors are fewer in number... The spots of light at lower right is the cooling crusting overflow.
And my breath is held, fingers crossed, prayers being said (not that any of thatʻll help much in the face of an insistent Pelehonuamea)...Perhaps Pohoiki will be spared? Sheʻs a half mile away... the harbor is that tiny cove, with the home of the ʻohana Hale (huh-ley).
We shall, of course, wait and see what happens. Meantime, Iʻm out for a stroll the misty rains.
As always, with aloha... and no foʻget:
be outside...pay attention noho i waho...a maliu
BobbyC
maniniowali@gmail.com
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