March 2020 was a particularly calm month at Piton de la Fournaise, according to the OVPF:
The replenishment of magma and the pressurization of the surface magmatic reservoir which had resumed following the end of the eruption of February 10-16, ceased around March 10, 2020.
At the same time, seismicity remained low in March, with less than one earthquake per day recorded under the summit craters.
Note that during the last two days of March, 3 and 7 superficial volcano-tectonic earthquakes were recorded.
Piton de La Fournaise - Histogram representing the number of surface volcano-tectonic earthquakes recorded in March 2020 (© OVPF-IPGP).
Piton de La Fournaise - Illustration of the deformation over the last six months (October 1, 2019 - March 31, 2020) the eruptive and intrusive periods are shown in red and green respectively. Here are shown the variations in distance between two GPS receivers crossing the Piton de la Fournaise building, at the top (reference SNEG; top), at the base of the terminal cone (reference FJAG; in the middle) and in the far field (reference PRAG ; below) (see location in Figure 5). An increase is synonymous with elongation and therefore swelling of the volcano; conversely, a decrease is synonymous with contraction and therefore deflation of the volcano (© OVPF-IPGP)
Since 2016, replenishments of the surface magmatic reservoir under the Piton de la Fournaise have been done in pulses, so such phases of lull in deformations and seismicity have already been observed several times between 2016 and 2019 over periods ranging from 15 to around 80 days.
The still high values of CO2 fluxes in the far field soil show that deeper magma ascent (at the level of the mantle) continues but that these have not yet reached the surface reservoir, at the end of March.
A seismic crisis was recorded on the instruments of the Volcanological Observatory of Piton de la Fournaise this April 2, with 92 superficial volcano-tectonic earthquakes detected between 8:15 am and 8:51 am local time.
This seismic crisis was accompanied by rapid deformation (of the order of 10-20 micro-radians). This indicates that magma has left the surface magmatic reservoir and has spread to the surface.
This seismic crisis, like the signals, shows:
1) a resumption of seismicity in general under the Piton de la Fournaise massif since March 30,
2) accompanied by a resumption of building inflation for two days,
show that the superficial magmatic reservoir pressurizes again.
A rash is therefore not ruled out in the medium term.
Alert level: Alert 1
- OVPF - Monthly bulletin for March 2020. - link
- OVPF - Activity bulletins of April 2, 2020 - link
In Guatemala, the Santiaguito presented on April 1, 2020 a plume of vapors, accompanied by a little ash 400 meters above the summit, drifting west and southwest over the Palajuno area and the villages of Loma Linda and San Marcos; the explosions remain weak.
Sources: Conred & Insivumeh
In the Northern Kurils, the Ebeko continues its eruptive activity; it is weak and characterized this April 1 by a plume of ash at 1,700 meters asl. , drifting northeast from the volcano for 5 km., according to observations by volcanologists based in Severo-Kurilsk.
The aviation code remains orange, ashes explosions can affect aviation at low altitude.
Sources: KVERT & VAAC Tokyo
In the past 24 hours, the Popocatépetl volcano monitoring system has identified 100 exhalations accompanied by water vapor, volcanic gases and slight amounts of ash, as well as an explosion on March 31 at 10:08 a.m.
In addition, there were 500 minutes of tremors, and three volcano-tectonic earthquakes with a calculated magnitude of 1.7, 2.1 and 1.7, respectively.
Since 10 a.m. on April 1, there has been an emission of volcanic gases and slight amounts of ash scattered west-southwest.
The alert remains set to amarillo Fase 2.