Activity of Popocatépetl, La Fournaise, Sakurajima and Reventador.

During the past 24 hours, thanks to the monitoring systems of the Popocatépetl volcano, 67 exhalations have been detected accompanied by water vapor, volcanic gases and slight amounts of ash.

Today September 23 at 04:26 (local time) an explosion was detected which, due to the energy and seismic amplitude, was classified as minor. Note that on September 22, there are 4 explosions, and on September 21, 7 explosions mentioned by Cenapred.

In addition, 52 minutes of tremor were recorded.

During the morning and at the time of this report, a continuous emission of water vapor and volcanic gases towards the west-northwest is observed.

CENAPRED urges not to approach the volcano and especially the crater, because of the danger of falling ballistic fragments (image 9) and, in case of heavy rains, to stay away from the bottom of the ravines because of the danger of mudslides and rubbish.

The Popocatépetl volcanic alert is in YELLOW PHASE 2.

Sources: Cenapred and webcams from Mexico

The eruption started on 09.19.2022 around 07:48 local time continues at Piton de La Fournaise.

After almost 3 days of decrease, the amplitude of the eruptive tremor (indicator of a lava emission on the surface) gradually increased again during last night. Its level stabilized during the day at around 20% of its initial amplitude.

Due to the very bad weather conditions on site,

- no field reconnaissance could be carried out by the OVPF-IPGP teams, whether on foot or by air,

- no image allowing to visualize a possible evolution of the eruptive site by the cameras of the OVPF/IPGP could be made.

Despite these unfavorable weather conditions on the Piton de la Fournaise over the past 24 hours, some lava flow estimates have been established by satellite method on the HOTVOLC platform (OPGC - Clermont Auvergne University). These estimates indicate a relatively stable flow over the period estimated at around 4 m³/s.

The COPERNICUS program developed by the European Commission provides images from the TROPOMI instrument for observing the composition of the atmosphere, and in particular sulfur dioxide. The images of September 19, 20, 21 and 22 indicate a weak plume, rising slightly towards the NNW, probably at low altitude (2-3 km). On the image of 09/22/2022 (noisy, because the volcano falls on the edge of the track), we can still see a weak plume drifting towards the SW. This direction is consistent with a transport around 2 km altitude, and the distribution of winds (deduced from the ERA-5 weather model). The masses of SO2 visible on Sept 21 and 22 are very low (approx < 1 kton) and difficult to quantify.

Alert level: Alert 2-1 (eruption in the Enclosure without any particular threat to the safety of people, property or the environment).

Source: OVPF-IPGP

Find all the information relating to the activity of Piton de la Fournaise on the various OVPF-IPGP media: - the website: ipgp.fr/fr/ovpf/actualites-ovpf - the Twitter account: twitter. com/obsfournaise - the Facebook account: facebook.com/ObsVolcanoPitonFournaise

Eruptive activity continues at Sakurajima, with explosions and nocturnal incandescence seen on high-sensitivity webcams.

The JMA reports 4 explosions on September 19, 27 on September 20, 4 explosions on September 21, 1 explosion on September 22 and 2 on September 23 at 3 p.m.; they concern the Minamidake crater, with plumes of gas and ash up to 2,400 meters above the edge of the crater, and expulsion of large blocks up to 700 m. from the crater.
In the field survey conducted on 22.09, the release of volcanic gas (sulphur dioxide) is 1,900 tons per day (previous measurement on September 12: 2,400 tons).

According to continuous GNSS observations over a wide area, it is believed that magma has accumulated in the depths for a long time and volcanic gas (sulphur dioxide
(yellow) was released in generally large quantities, so eruptive activity can be observed at the present time.
Eruptive activity is thought to continue into the future, centered on Minamidake's summit crater.

Source: JMA (subject to good translation)

Reventador activity, in Ecuador, is moderate and unchanged.

The IGEPN reports for the period from 22 to 23.09.2022 at 11 a.m. gas and ash emissions observed, reaching heights of up to 1200 meters above the level of the crater in a west and northwest direction.

The Washington VAAC reported 3 ash emissions with heights of 1338 meters above the summit in a northwesterly direction.

At night and early in the morning, incandescence was observed in the crater and the rolling of blocks up to 600 meters below the summit on all sides of the volcano. The lava flow on the northeast flank remains active.

The FIRMS system recorded 5 thermal anomalies and the MIROVA system recorded 1 moderate thermal alert in the last 24 hours.

Seismicity is characterized by:

- 47 blast earthquakes (EXP)
- 83 Long Period earthquakes (PL)
- 13 episodes of emission tremor (TREMI)
- 2 episodes of harmonic tremor (TRARM)

Alert level - SNGRE: Orange

Source: IGEPN