Loihi submarine volcano (Hawai'i): earthquake swarms might indicate ongoing or coming eruption
lun, 26 giu 2017, 07:3807:38 AM | AUTORE: T
Since late May, the volcano hidden beneath the Pacific south of Big Island has been showing markedly increased seismic activity. Several earthquake swarms were detected under the volcano.
Recent earthquakes under Loihi volcano (Hawai'i)
This probably suggest that magma has been intruding into the volcanic edifice recently. Whether it also indicates that the volcano is currently erupting or about to do so, remains unknown.
Due to its great depth (about 1000 meters below the sea surface), eruptions from Loihi are difficult to detect with certainty and would not show any visible signs on the surface. The water pressure is too large to prevent any explosive activity reach the surface and erupted material is dispersed too quickly to reach the surface in significant quantities.
So far, there have been 4 recent seismic swarms:
1: The first earthquake swarm occurred on 26 May 2017 under the southern rift zone of the volcano, at approx. 11 km depth.
2: The second swarm comprised a few shocks on 7 and 8 June also under the southern rift zone at 8-11 km depth.
3: The third swarm took place between 11 and 12 June at depths between 12.5 and 9 km, with scattered locations under the eastern slope of Loihi.
4: The fourth earthquake swarm, so far the largest, occurred between 15-18 June with hypocenters between 1.5-17 km under the southern rift zone.
Since then, only two small quakes of magnitudes around 2 have been detected on 22 and 23 June, under the eastern and southern flanks at 13 and 8 km depth.
Mon, 26 Nov 2012, 10:26
Un terremoto di magnitudo 4.2 è stato rilevato al Loihi vulcano il 25 novembre. Aspettiamo e vedere se l'Osservatorio hawaiano del vulcano ha informazioni più su questo. ... Read all
Wed, 12 Sep 2001, 06:00
Loihi volcano (Hawaiian Islands, USA) - Smithsonian / USGS Weekly Volcanic Activity Report for 12 September-18 September 2001 (New Activity / Unrest)
An earthquake swarm occurred at Loihi during 10-11 September and two 13 September earthquakes may have also been part of the swarm. The two later earthquakes occurred at 0311 and 0839 and had magnitudes of 4.9 and 4.4, respectively. Most of the earthquakes from 10-13 September were ~12 km deep and located slightly S of the summit of the volcano. ... Read all
Wed, 5 Sep 2001, 06:00
Loihi volcano (Hawaiian Islands, USA) - Smithsonian / USGS Weekly Volcanic Activity Report for 5 September-11 September 2001 (New Activity / Unrest)
On 10 September an earthquake swarm began at Loihi. The swarm began with a M 5 earthquake and was followed by M 3.5-4.5 earthquakes until at least 11 September. This was the most severe swarm at Loihi since July 1996, when the summit collapsed. ... Read all