But Biggs tells Scientific American that satellite data has hinted at potential volcanic activity more recently. “I would be really surprised if [more than 12,000 years ago] really is the last eruption date,” she says to the publication.
The Geologyhub channel has various updates and information on the Hayli Gubbi volcano (and others across the world) for those curious: https://www.youtube.com/@GeologyHub/videos
From there - yeah, zero volcanoes had modern scientific monitoring before ~1980. Some have a few thousand years of written records...well, at least of major eruptions. Nobody ever kept "what did the volcano do today?" diaries.
So generally - eruption records depend on field geologists doing a lot of grunt work around a volcano, trying to work out details of its geological history. And in a very poor, remote country like Ethiopia - which has also a history of border conflicts, civil wars, and other nastiness - geologists both bold and well-funded enough to do such field work may be rather scarce.
Result - an eruption record may amount to "we have no real evidence that it's done anything big since maybe somewhere around X-ish thousand years ago".
How about 12,000 years of overlapping ring patterns from paleo trees?
Live trees, dead trees in buildings, bogs, tidal zones, etc.
There's also sedimentation layers from multiple scattered bore samples that will reveal more about patterns of particle fall from the skies and layered flows from years past.
This particular fact somewhat undercuts your strong assertion:
> Not a chance.
as there are actual well documented trees in the region that do form annual rings. The Afar isn't solely vegetated by Dracaena ombet which lack annual rings.
> This particular fact somewhat undercuts your strong assertion:
My strong assertion, was not "there are no trees". Of course there are some trees of some size in some places. Not the same as an oak forest, but still.
My strong assertion was regarding how very unlikely "12,000 years of overlapping ring patterns" would be from the sparser and smaller and less long-lived vegetation.
You might want to look deeper into the links I provided re: dendrochronology.
There's no necessity for 12K years of volcano adjacent tree ring sources, any more than there's a requirement that the current immediate vicinity have many trees.
I can leave that for you to ponder, it's not hard to fathom why.
The scope of volcano eruption also comes into play, of course, there's a bunch of papers about tree rings and evidence of volcanic eruption wrt: The Black Death (1347 - 1353) in Europe with a wide separation between volcano and tree ring sites.
The Tanami's tough country, it's where the last people (known) to first encounter "western" civilisation walked out from. It's where several of them returned after a few years of exposure.( https://www.bbc.com/news/magazine-30500591 )
Do you have any stories of your time in the Ethiopian Afar that provide first hand field experience for your strong assertion?
Getachew Eshete and Göran Ståhl did some work there in 1999 in the Rift Valley part of the Afar region that indicated Acacia growth rings can be used as climate indicators for the 30 year life span periods of the wood studied.
I specifically meant live trees, didn't really occur to me that dead trees could be relevant. Not sure how common it is to find 12000 year old dead trees either but I guess it's more common than live ones.
And of course geological surveys would definitely tell you something about the past
The real problem with tree rings here in this specific case is ... Ethiopia .. not a lot of big trees now, nor in the recent past when it was grasslands - but not really my field - there's likely to be very slow growing unassuming trees that are surprisingly old there .. and remains of older trees that have overlapping ring sequences.
But yes - geological / geophysical clues are likely more relevant here.
It's weird. The "records" in question appear to be those kept by the Smithsonian:
> The Smithsonian Institution’s Global Volcanism Program has no record of any eruptions of Hayli Gubbi during the Holocene, the current geological epoch, which began at the end of the last ice age, about 11,700 years ago.
But I'm fairly confident that the Smithsonian's records don't go back more than 700 years.
Not as any significant factor of cause of this eruption, no.
There will be some contribution to atmospheric makeup, of course. Whether that increases or decreases current insulation factor depends on what the cloud makeup is, where it rises to, how far it spreads, and how long it stays aloft.
I have located no accredited scientific studies yet that discuss how the loss of gigatons of ice compressing the entire planets structure from the poles will impact the planet as a whole. With even a basic understanding of mass and physics however one can deduce from that comprehension an irrefutable change will occur in the planets crust. If one were to research the pattern of volcanic activity from the start of human recorded existence alone then one may learn something new. Most of our species fails to think in time, only worried about today, however as the changes in our only planet set in from 'progress' more will be forced to look back over time and reconsider where we failed.
Search for “post-glacial rebound” or “glacial isostatic adjustment”.
This has been thoroughly studied and is well known to geologists, especially in Northern Europe where changes can occur over human time scales.
I remember watching a documentary about a landslide disaster that occurred because clay saturated by salt water had lifted above sea level due to GIA and the fresh rainwater had washed the salt out. Clay without salt ions is more liquid and eventually moved catastrophically.
Greatly appreciative of the intellectual verbiage guidance that will certainly lead me down a deeper rabbit hole for my interests. This HN site has been one of my greatest finds on all of the web and the knowledge I have learned and put to work from those here choosing to share such insight has forever changed me. Thanks again.
.. and pretty much why I worded the first line of my comment above as I did.
Sea level changes, glacial retreats, etc will all change crustal pressures and impact the frequency, placement, and nauture of volcanic activity in times to come.
Not a lot of that in Ethiopa for now though (to the best of my current "haven't specifically looked at the map for this" gut feeling).
But Biggs tells Scientific American that satellite data has hinted at potential volcanic activity more recently. “I would be really surprised if [more than 12,000 years ago] really is the last eruption date,” she says to the publication.
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