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Old 2021-09-15, 15:07   #500
Dr Sardonicus
 
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La Palma, Canary Islands: seismic crisis Sep 2021 - updates
Quote:
The volcanic-seismic crisis continues to evolve. During the past 24 hours, earthquakes have been moving westwards and become shallower, the National Geographic Institute (IGN) reported.

This is likely reflecting continued magma intrusion and migration under the surface, supported also by continued deformation of the surface in the same area as the quakes. In places, the ground has been uplifted by 1.5 cm (almost one inch) already.
<snip>
Hmm, I wonder of that should be 2.5 cm, since 1.5 cm is just under 5/8 of an inch, and 2.5 cm really is "almost 1 inch," which is 2.54 cm.
Quote:
The strong earthquake swarm is continuing beneath Cumbre Vieja, and now PEVOLCA has raised the alert level to Yellow, citing the repeated occurance of earthquake swarms since 2017, with this one being the strongest and also the shallowest, suggesting magma is slowly rising into the edifice. Measurements of Helium-3 gas flux are also indicating this.
<snip>
Helium-3? Why Helium-3 specifically? I could understand Helium-4 being present. Uranium (over 99% being U-238) is a common constituent of rocks. U-238 undergoes radioactive decay by emitting an alpha particle, and alpha particlesa are Helium-4 nuclei.
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