History, Politics And Current Affairs

Ice streams move due to tiny ice quakes: Dynamics of Greenland's ice decrypted
https://phys.org/news/2025-02-ice-strea ... uakes.html

The ice-streams' depths move in stick/slip wriggles and jerks as tiny faults gather stress, fail.

But these faults do not reach surface as 'slipped' by a layer containing much volcanic ash.
quote:
This layer stops the quakes from propagating to the surface. Analysis of the ice core showed that these volcanic particles originate from a massive eruption of Mount Mazama in what is now Oregon (U.S.) some 7,700 years ago.
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I wish they would have explained how they knew the ashes came from Mount Mazama.

jemhouston wrote: ↑Fri Feb 07, 2025 12:56 am I wish they would have explained how they knew the ashes came from Mount Mazama.

Easy. Physical shape of the ash and its isotopic and elemental signature. Taken together that ties ash to a particular eruption. Since we know what the Mazama caldera ash is like in those terms we can tie things together.

Thank you

Apologies for G/H typo in title, which I have now updated.

Four (4) 'seriously icky' monthly intra-ocular injections along, my door-frame's retinal bleed' is 'resolving well'. But my right fovea is still 'partially occluded'. May yet clear enough to reliably spot such typos before posting...

My left eye's 'progressing' cataract sadly fogs daylight vision. And, as yet, is 'un-ripe', unsafe to remove...

Next appt and scan in early-April, but vision unlikely to settle before Easter...
Huh...

Nik don't overdo it.