2021-05-22 Uitbarsting van de Nyiragongo vulkaan

2021 Nyiragongo Lava flow

Een nieuwe uitbarstingsactiviteit op de Nyiragongo-vulkaan begon op 22 mei rond 18.15 uur plaatselijke tijd (16.15 uur UTC). Terwijl de uitbarstingsactiviteit aan de oppervlakte enkele uren na het begin van de uitbarsting ophield, ging een ondiepe magmatische dijkintrusie die zich onder de steden Goma en Gisenyi en later onder het Kivumeer uitbreidde, gepaard met intense seismische activiteit die verscheidene dagen aanhield. Tijdens deze eruptieve activiteit werd en wordt de situatie nauwlettend in het oog gehouden door het Goma Volcano Observatory met de hulp van onder meer het Belgisch-Luxemburgse consortium (GeoRiskA/AfricaMuseum en het European Center for Geodynamics and Seismology/National Museum of Natural History (Luxemburg)). Er werd een internationale wetenschappelijke deskundigengroep opgericht om de situatie te volgen; deze groep heeft tot 8 juni 2021 een dagelijkse beoordeling gegeven. Een gedetailleerde tijdlijn van de gebeurtenissen is hieronder te vinden.

2021-05-24

Maps of Goma city, Nyiragongo lava flow probability (2019) and 22 May 2021 Nyiragongo lave flow are now avaiblable under this link.

Find below the timeline of the events, presented day by day.

2021-06-08: The seismic data, recorded over the last few days, indicate little change from the situation at the time of the last release on 4 June 2021. Since 31 May, the GPS network and satellite radar imagery have not detected any significant displacement in the region. movements in the region. Earthquakes and ash fallout could still occur in the coming weeks or months in the weeks or months in the Lake Kivu Basin. Observations suggest that the magma intrusion crisis is no longer evolving. Nevertheless intensive daily monitoring by the OVG and some of its partners continues.

2021-06-06: No change. The seismic data, recorded today, indicate little change from the situation on June 3rd. The GPS network did not detect any displacement at the stations today.

2021-06-05: The seismic data, recorded today, indicate little change from the situation on June 3rd. The GPS network did not detect any displacement at the stations today.

2021-06-04: The seismic data, recorded today, indicate little change from the situation on June 3rd. The GPS network did not detect any displacement at the stations today. The physical impossibility of installing seismic or GPS stations in the lake does not allow for accurate detection of possible magma upwelling under the lake. Further rockfall in the crater remains possible and could cause ash fallout in the surrounding areas. The favourable development of the situation continues, although a resurgence of activity cannot be completely ruled out. This justifies the continued intensive monitoring and daily reassessment of the situation by the GVO.

2021-06-02: Seismic data, recorded to date, indicate a continuing decrease in the number and magnitude of earthquakes and magnitude of earthquakes (most of them are not felt); the direction is southward under the lake. direction is towards the south, under the lake. The GPS network still indicates a decrease in the displacement velocities measured at the stations. The physical impossibility of installing seismic or GPS stations in the lake makes it impossible to detect to accurately detect any upwelling of magma beneath the lake. New satellite data recorded between 27 May and 1 June show that the ground continues to deform south of the town of Goma, albeit at a much slower rate than at the beginning of the than at the beginning of the eruption. These deformations can still create or extend existing ground fractures in the ground.

2021-06-01: Although earthquakes are still recorded, their energy is generally lower. However, there is some earthquake activity, mostly unfeelable, occurring southwards under Lake Kivu. The GPS network continues to show a decrease in displacement speeds measured at the stations. The physical impossibility of installing seismic or GPS stations in the lake makes it impossible to accurately detect a possible upwelling of magma under the lake. This decrease in energy released by the earthquakes, as well as in the GPS speeds, cannot yet be interpreted as indicating the cessation of volcanic activity. During phases of volcanic activity, periods of higher activity often alternate with phases of lower activity.

2021-05-31: Current earthquake (seismicity) and ground deformation data continue to indicate the presence of magma under the urban area of Goma with an extension under Lake Kivu. Although there are still earthquakes recorded, their energy is globally lower. Their location and the direction of the GPS displacements still indicate a halt or pause in the propagation of the magma intrusion towards the south. A decrease in displacement velocities measured by the GPS network still seems to confirm these observations. The physical impossibility of installing seismic or GPS stations in the lake makes it impossible to accurately detect any upwelling of magma under the lake.

2021-05-30: Current seismicity and ground deformation data continue to indicate the presence of magma under the urban area of Goma with an extension under Lake Kivu. Seismicity and deformation continue. Although seismicity above baseline is still being recorded, the Although seismicity above baseline is still recorded, the energy dissipated by these earthquakes continues to decrease. The location of the The location of the earthquakes and the direction of the GPS displacements indicate a halt or pause in the propagation of the magmatic intrusion towards the magmatic intrusion towards the south. A decrease in the displacement velocities measured by the GPS network seems to confirm these observations. GPS network seems to confirm these observations. However, the lack of resolution of the GPS and seismological networks, linked to the presence of the lake, does not allow us to exclude a possible future migration of the intrusion towards the surface. the intrusion towards the surface.

2021-05-29: Current seismicity and ground deformation data continue to indicate the presence of magma under the urban area of Goma with an extension under Lake Kivu. Seismicity and deformation continue. The number of earthquakes detected in 24 hours decreases slightly, as do the deformation rates. However, this decrease in the phenomenology at this stage cannot yet be interpreted as the end of activity. During phases of volcanic activity, periods of higher seismic activity often alternate with phases of lower seismicity. seismic activity often alternate with phases of lower seismicity. Seismicity above the baseline is always recorded. These observations are always consistent with the presence of magma at depth. Ash fallout may occur as a result of the collapse of parts within the crater. The data on the stability of Lake Kivu do not currently show any significant The stability data for Lake Kivu do not currently show any significant change (the latest available data is from 27 May 2021).

2021-05-28: Current seismicity and ground deformation data continue to indicate the presence of magma under the urban area of Goma with an extension under Lake Kivu. In the last 24 hours, seismicity, although less felt by the population, remains high, with hundreds of events per day still being detected by the GVO. In view of these results, we can expect the tremors to continue in the coming days. The location of these events seems to have stopped its progression towards the South but remains localized under Lake Kivu. Surface deformations are still recorded by the GPS network. These observations are consistent with the presence of magma at depth. Ash fallout may occur as a result of the collapse of parts of the crater. Data on the stability of Lake Kivu currently show no significant change.

2021-05-27: Current seismicity and ground deformation data continue to indicate the presence of magma under the Goma urban area with extension under Lake Kivu. Seismicity remains high and continues to migrate southwards and surface deformation is still recorded by the GPS network and InSAR. These observations are consistent with the continued propagation of magma at depth towards the south. Because of the partial drainage of the lava lake associated to the continuous collapse of the crater inside the summit of Nyiragongo, ash fallout may again occur. Data on the stability of Lake Kivu currently show no significant change. 

2021-05-26: By 22:00 UTC, 140 earthquakes had been recorded and automatically located in the last 24 hours, with magnitudes ranging from 2.1 to 4.8. Many more earthquakes of smaller magnitude were recoded. Seismicity remained sustained. It caused the collapse of several buildings and cracks in roads. However, it continued to migrate southwards.

2021-05-25: No return to eruptive activity has been observed. However, the seismicity remains very intense and felt by the population. More than 130 earthquakes of magnitude 2 to 5 were recorded in 24 hours as well as a large number of smaller earthquakes. Numerous reports of damages to houses and roads as well as multiple cracks are reported by the local population. The seismic swarm extended to Lake Kivu. A ash cloud occurred in the afternoon, probably linked to the crater collapse.

2021-05-24: At the eruption onset, the lava flowed eastwards and cut the N2 road (Goma- Rutshuru) near Kibati. Next, a new lava flow went southward and reached inhabited areas in Buhene. This lava flow stopped at 1.25 km from the international Airport of Goma during the night of May 22-23. As recorded on the KivuSNet seismic network and the KivuGNet geodetic network maintained by GVO, ECGS/MNHN and MRAC (see figures below), no precursors happened before the opening of the eruptive fissures on the volcano's flanks. This lack of precursors prevented any forecasting. At the time of writing, surface activity has ceased. However, an ongoing seismic swarm with several strong earthquakes (M3-4  and one M5) are still recorded on the KivuSNet seismic network. More information to come soon.

 

 

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