Piton de La Fournaise - 07.12.2020 the eruptive fissure - photo © Vincent Cheville / Lava tunnels -Rando Volcan
Piton de La Fournaise - Aerial reconnaissance and gas & lava sampling on 07.12.2020 - photo © OVPF-IPGP and SAG-PGHM
The third eruption of the year at Piton de La Fournaise, which began on December 07, 2020 at around 4:40 a.m. (appearance of the volcanic tremor) continued during the day.
The intensity of the volcanic tremor (indicator of the intensity of the eruption) after an increase phase at the start of the eruption, has been falling since 6 a.m. local time, even if this decrease has been decreasing since 9.15 a.m. local time (5.15 a.m. UT) .
At 3:00 p.m. local time, the highest altitude crack was the most active with the formation of 5 small eruptive vents. The two lower cracks showed a noticeable drop in activity. The OVPF-IPGP field teams were able to sample the gas and volcanic bombs.
The estimated surface flows, based on satellite data via the HOTVOLC platform (OPGC - University of Auvergne), relate to flows for the day of 07.12.2020 between 5 and 30 m³ / s.
Sulfur dioxide levels were high, and the gas plume rose on the west coast of the island.
Piton de La Fournaise - SO2 plume on 12/07/2020 / 10:17 UT - Sentinel-5 P Tropomi image / via Simon Carn
Piton de La Fournaise - images Sentinel-2 L1C 12.07.2020 bands 12,11,4 (above), and bands 12,8A, 4 (below) - one click to enlarge
Piton de La Fournaise - Evolution of the RSAM (indicator of the volcanic tremor and the intensity of the eruption) since 06.12.2020 4 p.m. local time (12 p.m. UT) on the BOR seismological station located to the south-west of the Bory crater (© OVPF-IPGP).
The eruption stopped today, December 8, 2020 around 7.15 a.m. local time (3.15 a.m. UT time), following a gradual drop in the tremor and a 3-hour phase of "gas piston" at the eruptive site (puff of gas or intermittent tremor) which are generally observed when the quantity of gas available is exhausted, and often synonymous with a decrease in surface activity.
No more surface activity is observed but no hypothesis is ruled out as to the evolution of the future situation (permanent shutdown, resumption of activity on the same site, resumption of activity elsewhere), seismicity still being recorded under the summit of the volcano.
The year 2020 saw only three eruptions, but also three intrusions of magma, without associated eruption. The Piton de la Fournaise therefore remains very active; It should be noted that he “changed his tune”, according to a well-known pattern of variations in the location of the eruptive site.
- OVPF / IPGP
- photos : Thierry Sluys et Vincent Cheville / Tunnels de lave Rando volcans
During the last 15 days, there has been a slight increase in the activity of Popocatépetl with more frequent ash emissions. Cenapred reports explosions on December 4, 5 and 6.
During the last 24 hours (06.12-07.12 / 17h GMT), 93 exhalations, accompanied by emissions of volcanic gases and, occasionally, ash, and 448 minutes of tremor have been identified. In addition, two volcano-tectonic earthquakes were recorded on 06.12 at 12:22 p.m. and 07.12 at 07:52 a.m., with a calculated magnitude of 2.1 and 2.0, respectively.
Since then, we observe the continuous emission of volcanic gases and sometimes ash, which disperse in a north-easterly direction.
CENAPRED urges NOT TO APPROACH the volcano and especially the crater, because of the danger posed by the fall of ballistic fragments and, in the event of heavy rains, to stay away from the bottom of the ravines because of the danger of lava flows. mud and materials. The Popocatépetl volcanic alert level remains at Amarillo Fase 2.
Sources: Cenapred and webcams of Mexico
A moderate eruptive activity of the Ebeko volcano continues on December 8, 2020. According to visual data from volcanologists from Severo-Kurilsk, the explosion sent ash up to 3.5 km altitude, and an ash cloud drifts towards the northeast of the volcano.
Ash explosions up to 19,700 feet (6 km) above sea level could occur at any time. Ongoing activities could affect low-flying planes and Severo-Kurilsk airport. The aviation code remains orange for these reasons.
Since December 1 and until today, a swarm of earthquakes has been underway under the eastern part of Yellowstone Lake.
Earthquake swarms are a common occurrence, with about half of all Yellowstone earthquakes occurring as part of these clusters of earthquakes in time and space.
Yellowstone lake - location, magnitude and cumulative number of earthquakes of seismic swarms 2020 and 2008-2009 - Doc. USGS - one click to enlarge
Compared to the 2008-2009 swarm, the current swarm is much smaller in terms of the total number of events and the energy they released, and the seismicity of the current swarm does not appear to migrate with time. It's interesting to note its location directly at the edge of the Yellowstone Caldera - a fault that formed due to the surface collapse in the most recent large explosive eruption 631,000 years ago.
Could this swarm be a reactivation of this border fault ? Only further research can answer this question, but swarms on faults delineating the caldera are relatively common.
Source: Yellowstone caldeta chronicles 07,12,2020