September 17, 2012 at 22:45
Dude…. CHIE’s noise level in that band went 3 sigma above yesterdays levels a little after 1300 UT (13:06:48 to be more exact) and has done so about 5 times since then.
What’s going on?
September 17, 2012 at 23:01
It could be interpreted as that and still be accurate.
A 3 sigma event, especially when it happens five times in the next 10 hours means that it’s not some random occurrence. Something is actually changing.
Carl le Strange says:
September 18, 2012 at 07:31
Micro update on El Hierro
El Hierro does not really merrit a new post right now, so here is todays brief update.
The ongoing earthquake swarm seems to loose it’s momentum and the earthquakes have centered in an area close to the middle of the “mercedes star” of the island. The earthquakes are in general smaller than previous and center around 20 km depth.
The reason for the loss of momentum is found in the new set of GPS points. It is clear that this new arrival of magma was small, about the same size as the one in late january early february. Maximum uplift is 20mm compared to the first one that led to the eruption with 50mm maximum value, and the third one with a maximum of 90mm.
Unless new magma arrives within the next few days the activity will dwindle out due to loss of systemic pressure as a driving force. Ie, that the pressure reaches an equilibrium with the surrounding crust thereby halting the possibility for new magma filling earthquakes to happen.
In a way, that small ongoing swarm to the north of the hotspring bath resort of Balneario Pozo la Salud is more interesting. It has been going on and off for more than a month now, it is quite possible that it is caused by magma moving up from the June bolus that went out to the south west. If so there is probably enough magma to sustain the activity for some time and could in theory get interesting.
[link to volcanocafe.wordpress.com