At Etna, on May 24, 2021, from 18:58 UTC, the resumption of Strombolian activity at the SE crater is observed; The forecast model indicates the dispersion of the eruptive cloud in the ENE direction.
Simultaneously with the resumption of Strombolian activity, we observe a sudden increase in the average amplitude of the volcanic tremor, which has reached medium-high values ... we are heading towards the 21 ° paroxysm !
The location of the center of gravity of the sources of the volcanic tremor is in the area of the SE crater at an altitude of about 2800 m slm .. Also at 18:58 UTC there is an increase in both the rate of occurrence of infrasound. events and their magnitude. The events are located in the SE crater area.
Soil deformation monitoring networks do not show significant variations.
Etna SEC - 24.05.2021 - lava fountain, view of Marina di Riposto - photo Gio Giusa - one click to enlarge all photos
At around 8:10 p.m. UTC, a further increase in the average amplitude of the volcanic tremor is observed, which in a few minutes reaches very high levels. The center of gravity of the volcanic tremor sources continues to be located in the SE crater region at an altitude of about 2700 m s.l.m.
At approximately 20:25 UTC, Strombolian activity at SE crater turned into a lava fountain with the formation of an eruptive cloud which disperses according to the forecast model in the ENE direction. The eruptive column reached 7,000 meters asl. during Fountaining.
Etna SEC - 24.05.2021 / 22:23 - Lava fountain; the haze in layered layer is due to fires - photo Boris Behncke
A decrease in the value of the parameters begins around 9.45 p.m. UTC, and the INGV announces at 10:07 p.m. UTC the end of the lava fountain activity. A lava flow is observed which propagates in a southwest direction.
Sources: INGV OE & INGVvulcani - photos INGV, Boris Behncke and Gio Giusa
We take a look back at the eruption of Nyiragongo, which began on May 22 at around 6:15 p.m. local time (4:15 p.m. UTC). At the start of the eruption, lava flowed east and cut the N2 road (Goma-Rutshuru) near Kibati. Then, a new lava flow headed south and reached inhabited areas in Buhene. This lava flow stopped 1.25 km from Goma international airport on the night of May 22 to 23.
As recorded on the KivuSNet seismic network and the KivuGNet geodetic network maintained by GVO, ECGS / MNHN and MRAC, no precursor occurred before the opening of the eruptive cracks on the flanks of the volcano. This lack of precursors prevented any forecast.
Nyiragongo - Seismic activity of 05/22/2021 - Nyiragongo - Automatic hourly count of short period (SP) and hybrid earthquakes during the last 3 days (from midnight on May 22; last update on May 24 at 4 pm : 54 UTC) Each bar is an hourly count. The first seismic and acoustic peaks on May 22 at around 4:15 p.m. UTC occurred almost simultaneously with the first visual observations of the surface eruption, observed between 4:00 p.m. and 5:00 p.m. UTC. - Doc. https://georiska.africamuseum.be/ Benoit Smets
On May 25, surface activity ceased. However, an ongoing seismic swarm with several powerful earthquakes (M3-4 and one M5) are still recorded on the KivuSNet seismic network. According to Rwanda's earthquake service, the epicenter was on the north shore of Lake Kiwu, a few kilometers from the Goma / Gisenyi agglomeration. It reached magnitude 5.1. At first there was no depth information.
The consequences of the series of earthquakes, which have been going on since yesterday and which began immediately after the eruption of Mount Nyiragongo on Saturday evening, are serious for the towns and the immediate surroundings: several buildings have collapsed in Gisenyi and in the district. adjacent to Rubavu, and many others was damaged. The new earthquake on Monday made the situation worse.
Several people have died in the city as a result of collapsing buildings, according to local journalists.
Source: Benoit Smet, via https://georiska.africamuseum.be/
The progression of the seismicity of the first eruptive fissure at the foot of Nyiragongo south of Goma (DRC) / Gisenyi (Rwanda) is clearly visible. - a) Counting zones for seismic and earthquake events located automatically on May 22, 23 and 24, 2021 (last update on May 24 at 4:50 p.m. UTC); b) Another representation of the automatic earthquake location map on May 22, 23 and 24 (last updated May 24 at 4:50 p.m. UTC) where the color scale corresponds to the time of origin of each event. - Doc. https://georiska.africamuseum.be/