(08-09-2022, 04:01 PM)Ccat Wrote: Somebody, privately, suggested that the town/area of Volcano might be hit next. How would that work? It’s nearly higher than kiluaea.
Ah, another one of those questions about the Madame whose answer is more than a one liner… and for me, at least, intriguing..
If it was a one liner, it would be simple, the town/area of Volcano, for the most part, even though it is rather close to the eruptive center at Kilauea volcano is shielded from inundation because of topographic features that make it virtually impossible for lava from Kilauea to flow there. The vent is well below the height of the caldera it is in, the same caldera whose walls would have to be scaled to get anywhere near Volcano. So a simple no, there’s no danger, will do.
Also true is that Volcano Village, even though it is within spitting distance from Kilauea’s summit is, predominately, up wind and as such was saved from much of the ash fall during the collapse events of 2018. But the 1790 collapse, which was much bigger and encompassed the entire caldera, did leave a thick layer of ash over the entire area. Not so much as to destroy everything, but I suspect life there would be challenging for a while if that were to happen today.
But, and this is where it gets interesting, there is a very real threat to the Volcano area from lava flows coming from Mauna Loa. Not so much the Village, at least initially, but when we consider that Volcano encompasses an area from the Golf Course Subdivision in the west, to (let’s say) Akatsuka Orchids in the east, and the Volcano Farm Lots in the north, then one of the areas considered most likely to erupt when Mauna Loa next erupts (where that cluster of vents near the Red Hill cabin at the 9,000 foot elevation on Mauna Loa’s NorthEast Rift Zone is) is likely to issue flows that would inundate parts of Volcano.
There’s a lot of nuances, a lot of subtle issues with terrain and such, but after watching Pele find that little nook around the north side of Green Mountain and devour Kapoho before any of us recovered from the shock gave one a much greater appreciation for the subtleties. So.. consider this..
From.. https://pubs.geoscienceworld.org/gsa/geo...-migration
Implications of historical eruptive-vent migration on the northeast rift zone of Mauna Loa Volcano, Hawaii by JPL
Which begins..
Five times within the past 138 yr (1852, 1855-1856, 1880-1881, 1942, and 1984), lava flows from vents on the northeast rift zone of Mauna Loa Volcano have reached within a few kilometres of Hilo (the largest city on the Island of Hawaii). Most lavas erupted on this rift zone in historical time have traveled northeastward (toward Hilo), because their eruptive vents have been concentrated north of the rift zone's broad topographic axis. However, with few exceptions each successive historical eruption on the northeast rift zone has occurred farther southeast than the preceding one. Had the 1984 eruptive vents (the most southeasterly yet) opened less than 200 m farther southeast, the bulk of the 1984 lavas would have flowed away from Hilo. If this historical vent-migration pattern continues, the next eruption on the northeast rift zone could send lavas to the southeast, toward less populated areas.
It's a subscription site but the first page along with the drawings is enough to make the point that it's reasonable to assume there is potential for lava from that point on Mauna Loa's Rift to flow towards Volcano.
With that in mind, when we consider the blue line mapping (the path water would take flowing towards the sea from any point of origin on the island) applied to that area (anecdotally - I saw this years ago when a development was being contemplated for Stainback Highway and a geological assessment done while the project was being considered) the flows, if they originated from that area on the rift and fell to the south of the rift would go through the Volcano Farm Lots, and slip over Highway 11 into Fern Forest at about Akatsuka Orchids. And, a similar path, but adjusted slightly to the west at the point of origin, would have the lava flow towards the Volcano Golf Course Subdivision.
And still, a lot of us assume Volcano sits on a prominence and flows from Mauna Loa would be unable to be reach the area. It just ‘feels’ that way, right? Unfortunately, I do not think the topography supports that supposition. The saddle, if there is any, between the Golf Course and Mauna Loa’s flank is negligible and flows coming there may pool before they fall to the west (Pahala) or east (Puna), and in that pooling build a structure that is equal to or greater in height than the town of Volcano itself.
So, in reality, I suspect Volcano has a greater chance of volcanic inundation over the next so many years than does any other part of Puna. At least until Kilauea’s magmatic system is recharged. Ain’t that the strangest thing you’ve ever heard?