April 30, 2024. EN. Indonesia : Ruang , Colombia : Nevado Santa Isabel , Hawaii : Kilauea , Guatemala : Fuego , Costa Rica : Poas .

April 30 , 2024.

 

Indonesia , Ruang :

Increase in activity level of G. Ruang from level III (SIAGA) to level IV (AWAS)

The evaluation report on the activity of G. Ruang, North Sulawesi is hereby submitted as follows:

I. Visual observation
G. Ruang’s visual observations for the period April 15-30, 2024 generally showed the mountain clearly until it was covered in fog. Smoke from the main crater was observed white, gray and black in color with low, medium to thick intensity at a height of approximately 50 to 1,800 meters above the summit.

On April 30, 2024 at 01:15 WITA, an eruption occurred with the height of the eruptive column reaching 2,000 meters above the summit of G. Ruang. The eruption was accompanied by roaring sounds and the tremor was felt continuously.

II. Instrumental observation
Between April 1 and 28, 2024, the earthquakes recorded on G. Ruang were:

6 eruptions/explosions earthquakes,
15 avalanche earthquakes
1 harmonic tremor,
1 non-harmonic tremor,
3 continuous tremors,
2,057 deep volcanic earthquakes (VTA),
1,018 superficial volcanic earthquakes (VTB),
32 times local tectonic earthquakes,
195 Deep tectonic earthquakes.
The earthquakes were recorded 7 times on the MMI I scale. The G. Ruang seismic station was damaged due to the eruption on April 17, then the Geological Agency team installed a replacement station at the Ruang PGA station and began operations on April 20, 2024.

On April 29, 2024, the period 00:00-24:00 WITA recorded:
15 avalanche earthquakes
237 shallow volcanic earthquakes,
425 times deep volcanic earthquakes,
15 local tectonic earthquakes,
6 distant tectonic earthquakes.
During this period, there was another increase in seismicity on Mount Ruang, particularly in the number of deep volcanic earthquakes.

III. Assessment
The number of deep and shallow volcanic earthquakes, which increased significantly on April 29, 2024, accompanied by visuals of smoke from the crater, shows that there is currently still a process of rock cracking accompanied by magma migration deep magma reservoirs towards the surface. This increase in activity has the potential to develop into explosive eruptions alternating with effusive eruptions (lava flows). The tremor was intense from 00:15 WITA until the eruption occurred at 01:15 WITA and continued intensely until this status increase bulletin was issued. The eruption occurred at 01:15 WITA with an eruption column of approximately 2,000 meters accompanied by roars and intense tremor felt.

IV. Recommendation
Based on the results of visual and instrumental monitoring which show an increase in volcanic activity on Mount Ruang, the activity level of Mount Ruang was raised from level III (SIAGA) to level IV (AWAS) from from April 30, 2024 at 1:30 a.m. WITA.

VOLCANO OBSERVATORY NOTICE FOR AVIATION – VONA

Issued : April 30 , 2024
Volcano : Ruang (267010)
Current Aviation Colour Code : ORANGE
Previous Aviation Colour Code : orange
Source : Ruang Volcano Observatory
Notice Number : 2024RUA007
Volcano Location : N 02 deg 18 min 11 sec E 125 deg 22 min 00 sec
Area : North Sulawesi, Indonesia
Summit Elevation : 2320 FT (725 M)

Volcanic Activity Summary :
Eruption with volcanic ash cloud at 00h35 UTC (08h35 local).

Volcanic Cloud Height :
Best estimate of ash-cloud top is around 18320 FT (5725 M) above sea level or 16000 FT (5000 M) above summit. May be higher than what can be observed clearly. Source of height data: ground observer.

Other Volcanic Cloud Information :
Ash cloud moving from east to south. Volcanic ash is observed to be gray to dark. The intensity of volcanic ash is observed to be thick.

Remarks :
Eruption followed by pyroclastic density currents to all direction.

Source : PVMBG

Photos : Fany Goha , Rév. Welman Boba , PVMBG .

 

Colombia , Nevado Santa Isabel :

Weekly activity bulletin: Nevado Santa Isabel Volcano

Regarding the monitoring of the activity of the NEVADO SANTA ISABEL VOLCANO, the MINISTRY OF MINES AND ENERGY, through the COLOMBIAN GEOLOGICAL SERVICE (SGC), reports that:

During the week of April 16 to 22, 2024, the recording of seismic activity associated with the fracturing of rocks inside the volcanic edifice continued. This seismicity increased in the number of earthquakes recorded and in seismic energy released compared to the previous week. The earthquakes were located mainly on the southeastern flank of the volcanic structure, at distances of up to 6 km from its central part and at depths between 2 and 7 km. The highest magnitude of the week was 1.2, corresponding to the earthquake recorded on April 21 at 11:45 p.m., located approximately 5 km southeast of the volcano, at a depth of 4 km. This earthquake occurred during the seismic increase recorded between April 21 and 22 in the aforementioned sector.

Carbon dioxide (CO2) flux rates, which began to be measured since late last year toward the southwest of the volcano (area known as La Azufrera), remain within a stable range.
The other parameters measured and used for the diagnosis of volcanic activity did not present significant changes during the period evaluated.

The alert status for volcanic activity remains at: YELLOW ALERT: ACTIVE VOLCANO WITH CHANGES IN THE BEHAVIOR OF THE BASE LEVEL OF MONITORED PARAMETERS AND OTHER MANIFESTATIONS.

Source et photo : SGC

 

Hawaii , Kilauea : 

Monday, April 29, 2024, 11:58 AM HST (Monday, April 29, 2024, 21:58 UTC)

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Activity Summary: 
Kīlauea volcano is not erupting. The significant increase in seismicity beneath the upper East Rift Zone and caldera south of Halemaʻumaʻu that began in the early morning of April 27 is continuing and has intensified. Updates are being provided daily while the heightened state of unrest continues.

Summit and upper East Rift Zone Observations:  
Earthquake activity increased sharply just after midnight on April 27 beneath the upper East Rift Zone (between Puhimau Crater and Hilina Pali road) and beneath Kīlauea caldera south of Halemaʻumaʻu. Earthquakes are occurring at depths of 1.5-2.5 km (1-1.5 miles) beneath the surface. Activity intensified yesterday and there have been over 360 earthquakes in the past 24 hours compared to 250 earthquakes in the previous 24 hours mostly beneath the upper East Rift Zone with fewer in the caldera south of Halemaʻumaʻu. In addition, the intensity of activity increased just after 11 p.m. on April 28, when several strong earthquakes including a magnitude 3.3 set off a swarm of earthquakes beneath the upper East Rift Zone that lasted for about 45 minutes. Activity returned to frequent small earthquakes less than magnitude 2 punctuated by occasional larger earthquakes with magnitudes between 2 and 3. The deeper earthquakes that were occurring 5-10 km (3-6 miles) directly beneath Kīlauea caldera over the past few weeks have ceased.

Kīlauea’s summit remains inflated. Overall ground deformation continues, with ongoing inflation of the summit and uplift south of the caldera. Tiltmeters near Uēkahuna and Sand Hill showed decreased rates of inflation and uplift on the evening of April 27 with the onset of a deflation-inflation (DI) event. The intense swarm of earthquakes recorded between 11 p.m. and midnight last night (April 28) coincided with increased inflation recorded on the Uēkahuna tiltmeter associated with the inflationary end of the DI event that began the previous day. Inflation at both tiltmeters returned to lower rates along with the seismicity just before midnight on April 28.  Sulfur dioxide (SO2) gas emission rates remain low. An SO2 emission rate of approximately 52 tonnes per day was recorded on April 23.

Rift Zone Observations: 
All seismic activity on the East Rift Zone is confined to the upper East Rift Zone, with no significant earthquakes or deformation occurring past the Mauna Ulu region. Seismicity in Kīlauea’s Southwest Rift Zone remains low overall. Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone—the site of 1983–2018 eruptive activity—continue to be below detection limits for SO2, indicating that SO2 emissions Puʻuʻōʻō are negligible.

Source : HVO

Photo : USGS/ M. Patrick

 

Guatemala , Fuego :

Weather conditions: partly cloudy.
Wind: northeast
Precipitation: 34.6 mm.

Activity:
5 to 8 explosions per hour with low to moderate characteristics are recorded, generating columns of gas and ash 4,500 to 4,800 meters above sea level (14,763 – 15,748 feet), dispersing for 10 to 15 km in a West and South-West direction.

The explosions are accompanied by weak to moderate avalanches which reach the edge of the vegetation; low to moderate rumbling, mostly weak shock waves, sounds like that of a train locomotive, and incandescent pulses with heights of 100 to 200 meters above the crater. The above generates fine ash falls in towns located to the West and Southwest of the volcano, such as Panimaché I and II, Morelia, Santa Sofía, Porvenir, Sangre de Cristo, Palo Verde and others.

Source : Insivumeh

Photo : Diego Rizzo.

 

Costa Rica , Poas : 

Daily report on the state of volcanoes. OVSICORI-UNA. Date: 2024-04-29. Updated at: 11:00:00.

Latitude: 10.2
Longitude: -84,233
Altitude: 2,687 meters above sea level

Activity observed:
Since midday yesterday, a slight emission of ash has been observed from vent C. The emission was more intense yesterday afternoon with columns reaching several hundred meters. Today the emission is lower with plumes poor in ash and at low altitude (<150m). Seismicity demonstrates tremors of variable frequency and amplitude with frequent small LP-type earthquakes. Yesterday afternoon, the MultiGAS station recorded a concentration of 42 ppm of SO2 (very high), and a CO2/SO2 ratio of 0.15 (very low). The SO2 concentration at the lookout peaked at 2.9 ppm this morning.

Environmental conditions: Mostly cloudy;
Wind: South-West
Activity Level: Warning (2)

Source et photo : ovsicori

 

30 Avril 2024. FR. Indonésie : Ruang , Colombie : Nevado Santa Isabel , Hawaii : Kilauea , Guatemala : Fuego , Costa Rica : Poas .

30 Avril 2024.

 

Indonésie , Ruang :

Augmentation du niveau d’activité  du G. Ruang du niveau III (SIAGA) au niveau IV (AWAS)

Le rapport d’évaluation sur l ‘activité du G. Ruang, Sulawesi du Nord est soumis par la présente comme suit :

I. Observation visuelle
Les observations visuelles de G. Ruang pour la période du 15 au 30 avril 2024 ont généralement montré clairement la montagne jusqu’à ce qu’elle soit recouverte de brouillard. De la fumée provenant du cratère principal a été observée de couleur blanche, grise et noire avec une intensité faible, moyenne à épaisse à une hauteur d’environ 50 à 1 800 mètres au dessus du sommet.

Le 30 avril 2024 à 01h15 WITA, une éruption s’est produite avec la hauteur de la colonne éruptive atteignant 2 000 mètres au dessus du sommet du G. Ruang . L’éruption était accompagnée de bruits de rugissements et le tremor a été ressenti en continu.

II. Observation instrumentale
Entre le 1er et le 28 avril 2024, les tremblements de terre enregistrés sur le G. Ruang étaient :

6 tremblements de terre d’éruptions/explosions,
15 tremblements de terre d’ avalanches
1 tremor harmonique,
1  tremor non harmonique,
3 tremors continus,
2 057 tremblements de terre volcaniques profonds (VTA),
1 018 séismes volcaniques superficiels (VTB),
32 fois tremblements de terre tectoniques locaux,
195 Séismes tectoniques profonds.
Les tremblements de terre ont été enregistrés 7 fois sur l’échelle MMI I. La station sismique G. Ruang a été endommagée en raison de l’éruption du 17 avril, puis l’équipe de l’Agence géologique a installé une station de remplacement au poste PGA de Ruang et a commencé ses opérations le 20 avril 2024.

Le 29 avril 2024, la période 00h00-24h00 WITA a enregistré :
15 tremblements de terre d’ avalanches
237 tremblements de terre volcaniques peu profonds,
425 fois tremblements de terre volcaniques profonds,
15  tremblements de terre tectoniques locaux,
6 tremblements de terre tectoniques lointains.
Au cours de cette période, il y a eu une autre augmentation de la sismicité sur le mont Ruang, en particulier du nombre de tremblements de terre volcaniques profonds.

III. Évaluation
Le nombre de tremblements de terre volcaniques profonds et peu profonds, qui a considérablement augmenté le 29 avril 2024, accompagnés de visuels de fumée issue du cratère, montre qu’il existe actuellement encore un processus de fissuration des roches accompagné d’une migration du magma des réservoirs de magma profonds vers la surface. Cette augmentation d’activité a le potentiel de se développer en éruptions explosives alternant avec des éruptions effusives (coulées de lave). Le tremor a été intense de 00h15 WITA jusqu’à ce que l’éruption se produise à 01h15 WITA et s’est poursuivi intensément jusqu’à ce que ce bulletin d’augmentation de statut soit émis . L’éruption s’est produite à 01h15 WITA avec une colonne d’éruption d’environ 2 000 mètres accompagnée de rugissements et d’un intense tremor ressenti.

IV. Recommandation
Sur la base des résultats de la surveillance visuelle et instrumentale qui montrent une augmentation de l’activité volcanique sur le mont Ruang, le niveau d’activité du mont Ruang a été relevé du niveau III (SIAGA) au niveau IV (AWAS) à partir du 30 avril 2024 à 01h30 WITA .

AVIS D ‘OBSERVATION DU VOLCAN POUR L’AVIATION – VONA

Publié : 30 avril 2024
Volcan : Ruang (267010)
Code couleur aviation actuel : ORANGE
Code couleur aviation précédent : orange
Source : Observatoire du Volcan Ruang
Numéro d’avis : 2024RUA007
Emplacement du volcan : N 02 degrés 18 min 11 sec E 125 degrés 22 min 00 sec
Zone : Sulawesi du Nord, Indonésie
Altitude du sommet : 2320 FT (725 M)

Résumé de l’activité volcanique :
Éruption avec nuage de cendres volcaniques à 00h35 UTC (08h35 locale).

Hauteur des Nuages Volcaniques :
La meilleure estimation du sommet du nuage de cendres se situe à environ 18 320 pieds (5 725 m) au-dessus du niveau de la mer ou 16 000 pieds (5 000 m) au-dessus du sommet. Peut être supérieur à ce qui peut être observé clairement. Source des données de hauteur : observateur au sol.

Autres informations sur les nuages volcaniques :
Nuage de cendres se déplaçant d’Est en Sud. Les cendres volcaniques sont grises à foncées. L’intensité des cendres volcaniques est observée comme étant épaisse.

Remarques :
Éruption suivie de courants de densité pyroclastiques dans toutes les directions.

Source : PVMBG

Photos : Fany Goha , Rév. Welman Boba , PVMBG .

 

Colombie , Nevado Santa Isabel :

Bulletin d’activités hebdomadaire : Volcan Nevado Santa Isabel

Concernant le suivi de l’activité du VOLCAN NEVADO SANTA ISABEL, le MINISTÈRE DES MINES ET DE L’ÉNERGIE, à travers le SERVICE GÉOLOGIQUE COLOMBIEN (SGC), rapporte que :

Au cours de la semaine du 16 au 22 avril 2024, l’enregistrement d’activité sismique associée à la fracturation des roches à l’intérieur de l’édifice volcanique s’est poursuivi. Cette sismicité a augmenté en nombre de séismes enregistrés et en énergie sismique dégagée par rapport à la semaine précédente. Les tremblements de terre ont été localisés principalement sur le flanc Sud-Est de la structure volcanique, à des distances allant jusqu’à 6 km de sa partie centrale et à des profondeurs comprises entre 2 et 7 km. La plus forte magnitude de la semaine a été de 1,2, correspondant au séisme enregistré le 21 avril à 23h45 , situé à environ 5 km au Sud-Est du volcan, à une profondeur de 4 km. Ce tremblement de terre s’est produit lors de l’augmentation sismique enregistré entre le 21 et le 22 avril dans le secteur précité.

Les taux de flux de dioxyde de carbone (CO2), qui ont commencé à être mesurés depuis la fin de l’année dernière vers le Sud-Ouest du volcan (secteur connu sous le nom de La Azufrera), restent dans une fourchette stable.
Les autres paramètres mesurés et utilisés pour le diagnostic de l’activité volcanique n’ont pas présenté de changements importants au cours de la période évaluée.

L’état d’alerte pour l’activité volcanique reste à : ALERTE JAUNE : VOLCAN ACTIF AVEC CHANGEMENTS DANS LE COMPORTEMENT DU NIVEAU DE BASE DES PARAMÈTRES SURVEILLÉS ET AUTRES MANIFESTATIONS.

Source et photo : SGC

 

Hawaii , Kilauea : 

Lundi 29 avril 2024, 11 h 58 HST (lundi 29 avril 2024, 21 h 58 UTC)

19°25’16 » N 155°17’13 » O,
Altitude du sommet :4091 pieds (1247 m)
Niveau d’alerte volcanique actuel : AVIS
Code couleur aviation actuel : JAUNE

Résumé de l’activité :
Le volcan Kīlauea n’est pas en éruption. L’augmentation significative de la sismicité sous la zone supérieure du Rift Est et la caldeira au Sud de Halema’uma’u, qui a commencé tôt le matin du 27 avril, se poursuit et s’est intensifiée. Des mises à jour sont fournies quotidiennement alors que l’état d’agitation accru se poursuit.

Observations du sommet et de la zone supérieure du Rift Est :
L’activité sismique a fortement augmenté juste après minuit le 27 avril sous la zone supérieure du Rift Est (entre le cratère Puhimau et la route Hilina Pali) et sous la caldeira du Kīlauea, au Sud du cratère Halema’uma’u. Les tremblements de terre se produisent à des profondeurs de 1,5 à 2,5 km (1 à 1,5 miles) sous la surface. L’activité s’est intensifiée hier et il y a eu plus de 360 tremblements de terre au cours des dernières 24 heures, contre 250 tremblements de terre au cours des 24 heures précédentes, principalement sous la zone supérieure du Rift Est, avec moins dans la caldeira au Sud du cratère Halema’uma’u. De plus, l’intensité de l’activité a augmenté juste après 23 heures  le 28 avril, lorsque plusieurs forts tremblements de terre, dont une magnitude de 3,3, ont déclenché une série de tremblements de terre sous la zone supérieure du Rift Est qui a duré environ 45 minutes. L’activité est revenue à de fréquents petits tremblements de terre de magnitude inférieure à 2, ponctués de séismes occasionnels plus importants avec des magnitudes comprises entre 2 et 3. Les tremblements de terre plus profonds qui se produisaient à 5 à 10 km (3 à 6 miles) directement sous la caldeira du Kīlauea au cours des dernières semaines ont cessé.

Le sommet du Kīlauea reste gonflé. La déformation globale du sol se poursuit, avec une inflation continue du sommet et un soulèvement au Sud de la caldeira. Les inclinomètres près d’Uēkahuna et de Sand Hill ont montré une diminution des taux d’inflation et une hausse dans la soirée du 27 avril avec le début d’un événement déflation-inflation (DI). L’intense essaim de tremblements de terre enregistrée entre 23 heures et 20 heures. et minuit hier soir (28 avril) a coïncidé avec une augmentation de l’inflation enregistrée sur l’inclinomètre d’Uēkahuna associée à la fin inflationniste de l’événement DI qui a commencé la veille. L’inflation aux deux inclinomètres est revenue à des taux plus bas, tout comme la sismicité juste avant minuit le 28 avril. Les taux d’émission de dioxyde de soufre (SO2) restent faibles. Un taux d’émission de SO2 d’environ 52 tonnes par jour a été enregistré le 23 avril.

Observations de la zone de rift :
Toute activité sismique sur la zone du Rift Est est confinée à la zone supérieure du Rift Est, sans tremblements de terre ni déformation significatifs ne se produisant au-delà de la région du Mauna Ulu. La sismicité dans la zone du rift Sud-Ouest du Kīlauea reste globalement faible. Les mesures des stations de surveillance continue des gaz sous le vent de Pu’u’ō’ō dans la zone du Rift du Sud-Est – le site de l’activité éruptive de 1983 à 2018 – continuent d’être inférieures aux limites de détection du SO2, ce qui indique que les émissions de SO2 du Pu’u’ō’ō sont négligeables.

Source : HVO

Photo : USGS/ M. Patrick

 

Guatemala , Fuego :

Conditions atmosphériques : partiellement nuageux.
Vent : nord-est
Précipitations : 34,6 mm.

Activité:
On enregistre 5 à 8 explosions par heure avec des caractéristiques faibles à modérées, qui génèrent des colonnes de gaz et de cendres de 4 500 à 4 800 mètres au-dessus du niveau de la mer (14 763 – 15 748 pieds), se dispersant sur 10 à 15 km en direction Ouest et Sud-Ouest.

Les explosions sont accompagnées d’avalanches faibles à modérées qui atteignent la lisière de la végétation ; grondement faible à modéré , d’ ondes de choc principalement faibles , de sons comme celui d’une locomotive de train et d’impulsions incandescentes avec des hauteurs de 100 à 200 mètres au-dessus du cratère. Ce qui précède génère de fines chutes de cendres dans les villes situées à l’Ouest et au Sud-Ouest du volcan, comme Panimaché I et II, Morelia, Santa Sofía, Porvenir, Sangre de Cristo, Palo Verde et d’autres.

Source : Insivumeh

Photo : Diego Rizzo.

 

Costa Rica , Poas : 

Rapport quotidien sur l’état des volcans. OVSICORI-UNA. Date : 2024-04-29 . Mise à jour à : 11 :00 :00.

Latitude : 10,2
Longitude : -84 233
Altitude : 2 687 mètres au-dessus du niveau de la mer

Activité observée :
Depuis hier midi, une légère émission de cendres a été observée depuis la bouche C. L’émission a été plus intense hier après-midi avec des colonnes pouvant atteindre plusieurs centaines de mètres. Aujourd’hui l’émission est plus faible avec des panaches pauvres en cendres et à basse altitude (<150m). La sismicité démontre des tremblements de fréquence et d’amplitude variables avec de petits séismes de type LP fréquents. Hier après-midi, la station MultiGAS a enregistré une concentration de 42 ppm de SO2 (très élevée), et un ratio CO2/SO2 de 0,15 (très faible). La concentration de SO2 au belvédère a culminé à 2,9 ppm ce matin.

Conditions environnementales : Généralement nuageux ;
Vent : Sud-Ouest
Niveau d’activité : Avertissement (2)

Source et photo : ovsicori

 

September 20, 2023. EN. Italy : Stromboli , Peru : Ubinas , Italy / Sicily : Etna , Indonesia : Semeru , Colombia : Nevado Santa Isabel .

September 20 , 2023.

 

Italy , Stromboli :

WEEKLY BULLETIN, from September 11, 2023 to September 17, 2023. (issue date September 19, 2023)

SUMMARY STATEMENT OF ACTIVITY

In light of the monitoring data, it appears:
1) VOLCANOLOGICAL OBSERVATIONS: During this period, normal Strombolian activity was observed with splashing activity in the North Crater area. The total hourly frequency fluctuated between medium values (11 events/h) and high values (19 events/h). The intensity of the explosions varied from low to medium in the North Crater area and from low to high in the South-Central area.
2) SISMOLOGY: The monitored seismological parameters do not show significant variations.
3) GROUND DEFORMATIONS: The island’s ground deformation monitoring networks did not show significant variations during the period studied.
4) GEOCHEMISTRY: Mid-level SO2 flux.
The CO2 flow in the Pizzo area shows stable values at average levels.
There is no update on the C/S ratio in the plume.
There is no update on the isotope ratio of dissolved helium in groundwater.
5) SATELLITE OBSERVATIONS: Thermal activity observed by satellite was generally at a moderate level.

VOLCANOLOGICAL OBSERVATIONS
In the observed period, the eruptive activity of Stromboli was characterized through the analysis of images recorded by the INGV-OE surveillance cameras at altitude 190m (SCT-SCV), from
Pizzo and Punta dei Corvi. The explosive activity was mainly produced by 3 (three) eruptive vents located in the North area of the crater and by 3 (three) vents located in the South Central area.

Observations of explosive activity captured by surveillance cameras
In the area of the North crater (N), with two vents located in sector N1 and one in sector N2, explosive activity of varying intensity from low (less than 80 m high) to medium (less than 150 m high). top) was observed. The products emitted in the eruption were mainly coarse materials (bombs and lapilli) sometimes mixed with fine materials (ashes). Furthermore, projection activity was observed in sector N1 which was intense on September 12. The average frequency of explosions fluctuated between 5 and 10 events/h.
In the South-Central (CS) zone, sectors S1 and C did not show significant activity while sector S2, with three active vents, even simultaneously, mainly showed explosive activity of variable intensity of low to high (more than 150 m in height), emitting coarse matter mixed with fine ashes. The average frequency of explosions oscillated between 6 and 9 events/h.

Field observations of September 11, 2023
On the morning of September 11, an inspection was carried out in the summit area in order to check the morpho-structural structure of the crater area and to observe the explosive activity produced by the crater areas.


In the area of the North crater, in sector N1, a very intense explosive activity was observed with the launch of coarse materials mainly towards the Sciara del Fuoco and the external side of the cone and a discontinuous projection activity both in frequency and in intensity, while in sector N2, two vents were noted with intense deflagrations linked to gas explosions, associated with weak and episodic projection activity coming only from the most central vent.
In the South-Central zone of the crater, in sector C, continuous degassing of the most central cone and alternating blasts with continuous degassing of the 2 hornitos were observed. In sector S1 there was a hornito characterized by slight degassing. In sector S2, activity was visible from at least 4 vents: a hornito near sector C which produced very noisy blast activity associated with discontinuous splashes; in addition, a second vent was adjacent to the previous one with frequent degassing alternating with modest explosions. From the other two vents in sector S2, violent vertical launches of mainly coarse material often occurred from the bulky hornito positioned in a near central position in the sector, often associated with a vent probably placed to the side of the hornito itself in which visible oblique emissions of ash were generated.
The products of the explosions in sector S2 fell back inside the crater terrace as they were almost vertical because there was no wind at high altitude. A sampling of fresh lapilli was carried out in the area near Fortini (under Pizzo towards Ginostra).

Source : INGV

Photos : G Costa , INGV

 

Peru , Ubinas :

Analysis period: September 11 to 17, 2023. Arequipa, September 18, 2023.
Alert level: ORANGE

The Geophysical Institute of Peru (IGP) reports that the eruptive processes of the Ubinas volcano (Moquegua region) maintain low to moderate levels. During this period, a volcanic explosion and gas emissions were recorded which reached up to 2600 m above the summit of the volcano. For this, it is suggested that the authorities maintain the volcanic alert level at Orange level.

During the analysis period, the occurrence of 144 volcano-tectonic (VT) type earthquakes was detected, associated with rock rupture processes that occur inside the volcano. In addition, 86 long-period (LP) seismic signals were recorded, associated with the movements of volcanic fluids (gas and magma), with a maximum energy of 0.3 Megajoules. During this period, a volcanic explosion was recorded on September 14, as well as 3 hours accumulated per day of seismic tremor in relation to ash emissions observed between September 14 and 16.

Surveillance cameras made it possible to identify emissions of gas and water vapor which reached heights of 2600 m above the summit of the volcano, which were dispersed mainly towards the South, South-East, East sectors. and North-East of the Ubinas volcano with a radius of 15 km. On the other hand, monitoring of the deformation of the volcanic structure shows variations of less than 5 mm of displacement (slight tendency towards inflation). Satellite monitoring has not shown thermal anomalies in the Ubinas crater.

RECOMMENDATIONS
• Keep the volcanic alert level at ORANGE level.

Source : Cenvul.

Photo : Ingemmet

 

Italy / Sicily , Etna :

WEEKLY BULLETIN, from September 11, 2023 to September 17, 2023. (issue date September 19, 2023)

SUMMARY STATEMENT OF ACTIVITY

In light of the monitoring data, it appears:

1) VOLCANOLOGICAL OBSERVATIONS: Degassing activity at the summit craters of the Bocca Nuova crater and the South-East crater.
2) SEISMOLOGY: Low seismic activity due to fracturing. Stationarity of volcanic tremor parameters.
3) INFRASOUND: Moderate to weak infrasound activity.
4) GROUND DEFORMATIONS: Over the past week, ground deformation monitoring networks have not recorded any significant changes.
5) GEOCHEMISTRY: SO2 flux at medium level
Soil CO2 flux slightly increasing compared to average values.
There is no update on the helium isotope ratio.
The partial pressure of dissolved CO2 does not show significant variations.
6) SATELLITE OBSERVATIONS: Thermal activity observed by satellite was generally weak.

VOLCANOLOGICAL OBSERVATIONS
During the reference week, monitoring of the activity of Etna was carried out through the network of surveillance cameras of the INGV – Osservatorio Etneo (INGV-OE) and through field observations carried out during certain inspections carried out by INGV-OE staff in the summit area.

During the observation days, the activity of Etna’s summit craters continued to be dominated by an intense degassing regime mainly affecting the Bocca Nuova (BN) crater. As observed in recent months, the gases emitted by this crater are characterized by a high temperature (~500 degrees) which is reflected in the flashes visible at night through the INGV surveillance cameras; on September 13 in particular, there was a transient degassing with particularly high temperatures observed by thermal surveillance cameras. The second gas contribution to Etna’s volcanic plume comes from the Southeast Crater (SEC), and is produced by the two vents located in the eastern sector of the cone by the numerous fumaroles located along the crater rim. Finally, the North-East crater (CNE) and the Voragine crater (VOR) showed, the first a weak fumarolic activity while the second showed no specific volcanic activity.

Source : INGV.

Photo : Etna guide ,

 

Indonesia , Semeru :

VOLCANO OBSERVATORY NOTICE FOR AVIATION – VONA

Issued : September 20 , 2023
Volcano : Semeru (263300)
Current Aviation Colour Code : ORANGE
Previous Aviation Colour Code : orange
Source : Semeru Volcano Observatory
Notice Number : 2023SMR301
Volcano Location : S 08 deg 06 min 29 sec E 112 deg 55 min 12 sec
Area : East java, Indonesia
Summit Elevation : 11763 FT (3676 M)

Volcanic Activity Summary :
Eruption with volcanic ash cloud at 01h50 UTC (08h50 local).

Volcanic Cloud Height :
Best estimate of ash-cloud top is around 13683 FT (4276 M) above sea level or 1920 FT (600 M) above summit. May be higher than what can be observed clearly. Source of height data: ground observer.

Other Volcanic Cloud Information :
Ash cloud moving to north. Volcanic ash is observed to be gray. The intensity of volcanic ash is observed to be medium.

Remarks :
Eruption recorded on seismogram with maximum amplitude 22 mm and maximum duration 100 second.

Source : Magma Indonésie

Photo : Andi Volcanist.

 

Colombia , Nevado Santa Isabel :

Nevado Santa Isabel Dome Complex Weekly Activity Bulletin

From the monitoring of the activity of the NEVADO SANTA ISABEL DOMES COMPLEX, the MINISTRY OF MINES AND ENERGY through the COLOMBIAN GEOLOGICAL SERVICE (SGC) reports that:

Due to the change in the system for measuring volcanic activity in the country that was presented on September 14, 2023 (Colombia modifies its system for measuring volcanic activity ), this volcanic structure goes to “yellow alert”. Indeed, since 2013, seismic activity has occurred at moderate levels, above its base level, characteristic of the Yellow volcanic activity alert state. In addition, certain geodetic data modeling work has shown a possible source of deformation towards the northwest sector of this volcanic structure. For all this, the SGC considers that this complex of domes must be placed on alert due to yellow volcanic activity: changes in the behavior of the base level of the monitored parameters and other manifestations.

For this reason, a bulletin on the activity of this volcanic structure will be published every week.
In the week of September 12 to 18, 2023, the low recording of seismicity linked to the fracturing of rocks inside the volcanic edifice continued. This seismic activity decreased in number of earthquakes recorded and seismic energy released, compared to the previous week. The earthquakes were of low energy (magnitude less than 1) and were located in the East and South-West sector, at an approximate distance of 4 to 5 km and at depths of between 4 and 5 km from the summit of the volcano.
The other parameters measured and used for the diagnosis of volcanic activity did not present significant changes during the period evaluated.

The alert status for volcanic activity remains at: YELLOW ALERT: ACTIVE VOLCANO WITH CHANGES IN THE BEHAVIOR OF THE BASE LEVEL OF MONITORED PARAMETERS.

Source : SGC

Photo :  Helmer Parra

 

January 12, 2022. EN. Ecuador / Galapagos / Isabella : Wolf , La Réunion Island : Piton de la Fournaise , Italy : Vulcano , Chile : Nevados de Chillan , Italy / Sicily : Etna , New Zealand : Ruapehu .

January 12 , 2022.

 

Ecuador / Galapagos / Isabella , Wolf :

The activity of the Wolf volcano is maintained

Minister Gustavo Manrique flew over the region of the Wolf volcano on Isabela Island, confirming that the eruptive activity was continuing. The lava flows are located less than five kilometers from the coast, on the east side of the island.
« The direction taken by the lava flows and the general development of the eruption allows us to stress that the pink iguana population remains safe, » said Minister Manrique.
The magma has traveled approximately 15 kilometers since the start of the activity, moved through ancient lava fields from previous eruptions and the vegetation of the arid zone of the Galapagos, where forests of rosewood, chala, rosemary and other species of native and endemic flora predominate.

“There is very little iconic fauna in the eruption impact area; however, species have evolved with these natural processes that are part of the normal dynamics of Galapagos ecosystems. The populations of iguanas, turtles and birds are found to the north of the volcano, where historically less volcanic activity has been recorded, ”added Danny Rueda, director of the Galapagos National Park.
Volcanic eruptions are natural processes that gave birth to the Galapagos Islands. The Ministry of Environment, Water and Ecological Transition continues to monitor this phenomenon to document the changes that may occur in the ecosystem.

VOLCAN WOLF DAILY ACTIVITY REPORT, Wednesday January 12, 2022.
From: January 10, 2022, 11:00 a.m. To: January 11, 2022, 11:00 a.m.

Surface activity level: very high
Surface trend: Descending
Internal: high
Internal tendency: Descending

Seismicity: The seismicity was carried out with data from the FER1 station
Volcano-Tectonics (VT) 1
Tremors of emissions (TREMI) 1

 

Emission / ash column:
Gas emissions from satellite images are moving towards the southwest.

Other monitoring parameters:
The MIROVA satellite system reported 2 extreme thermal alerts (16,030 and 18,190 MW) and 1 high (971 MW). The FIRMS satellite system has reported hundreds of thermal alerts in the past 24 hours.

Observation:
At the time of publication of this report, satellite images (Source: GOES16) associated with the Wolf volcano show a decrease in the amount of gas emitted (Source: Mounts), as well as the number of thermal alerts generated (Source: Mirova, Firms). The lava flows are believed to be very close to (or entering) the sea.

Sources : Parque Nacional Galápagos , IGEPN .

Photos : Parque Nacional Galápagos , Jeffo Marquez

 

La Réunion Island , Piton de la Fournaise :

Press release of January 12, 2022, 9:00 a.m.

The eruption that began on December 22, 2021 at around 3:30 a.m. local time continues. Over the last 48 hours, the amplitude of the tremor has increased. Fluctuations in the amplitude of the tremor can still occur; they are linked in part to the level of the lava lake, which varies according to the mode of degassing, the erosion of the eruptive duct and the sporadic openings of the tunnels which allow the cone to emptying.

As in most of Reunion, bad weather conditions persist on the eruptive site. However, some observations could be made thanks to short clearings. These show that the lava projections at the level of the cone are still present and occasionally exceed the height of the cone. Regularly overflows of the lava lake are observed as well as numerous resurgences of lava flows at the roof of the lava tunnel downstream of the cone.

The images from the OVPF-IPGP-IRT webcam located at Piton de Bert show that the new flow arm put in place over the past 48 hours, and which runs along the southern rampart, is still active.
The front of this flow progresses only very slowly given the relatively low slopes in the area.

Over the last 24 hours:
– Four volcano-tectonic earthquakes, of low magnitude (<0.5), were recorded under the summit.
– The surface deformations still show a deflation at the level of the summit zone, linked to the emptying of the magma reservoir located under the summit (at about 2-2.5 km deep) feeding the eruptive site.

– Due to the very bad weather conditions on the volcano, no lava flow could be estimated by satellite method with the HOTVOLC platform (OPGC – Clermont Auvergne University).

Alert level: Alert 2-1 (eruption in the Enclos )

Source et photos : OVPF

Read the article https://www.ipgp.fr/sites/default/files/ovpf_20220112_09h00_communique_eruption.pdf

 

Italy , Vulcano :

WEEKLY NEWSLETTER, from January 03, 2022 to January 09, 2022 (issue date January 11, 2022)

SUMMARY OF THE STATE OF THE ACTIVITY

In the light of the surveillance data, it is highlighted:
1) Temperature of the fumaroles of the crater: The temperature values are stable both on the edge of the crater and on the internal face.
2) CO2 flux in the crater area: no updated data.
3) SO2 flux in the crater area: SO2 flux at a high level
4) Geochemistry of fumarolic gases: no update available
5) CO2 flux at the base of the La Fossa cone and in the area of Vulcano Porto: The soil CO2 flux values measured at the base of the cone showed a slight increase, reaching medium-high values.

6) Geochemistry of thermal aquifers: The physico-chemical parameters of the Sicilia and Bambara Camping sites are stable.
7) Local seismicity: Very low values ​​in the frequency of occurrence of events of lower frequency (VLP).
8) Regional seismicity: No earthquake with Ml> = 1.0 was located in the area of ​​the island of Vulcano.
9) Deformations – GNSS: The GNSS network does not show any variations during the period under review.
10) Deformations – inclinometry: The inclinometric network does not show significant variations during the examination week.
11) Other observations: Gravimetry: The continuous gravity stations did not record any significant variations during the period considered.
GB-RAR: The results of the GB-RAR monitoring for the period from December 14, 2021 to January 10, 2022, show a general stability of the area, with deformations along the LOS of less than 1 mm.
Mobile GNSS: Mobile GNSS stations show no significant change.

SO2 FLOW INTO THE CRATER ZONE
The average daily values ​​recorded during the last week are in line with the values ​​for the previous period. In the period following the increase recorded since September and which had peaked at the beginning of November, the average daily stabilization value of the flow of SO2 decreased to a high level (~ 120 t / d).

CO2 FLOWS AT THE BASE OF THE CONE DE LA FOSSA AND IN THE VULCANO PORTO AREA
Soil CO2 fluxes (acquired automatically by the VULCANOGAS network), in the last days of the observation period, showed a moderate upward trend in all sites. In the sites of Camping Sicilia and Rimessa, the current values ​​remain high, although lower than those reached at the peak of the current crisis, while in the sites of Palizzi (P4max) and Faraglione, on the other hand, the flows have almost reached the maximum values ​​of the last 12 months.

LOCAL SEISMICITY
During the week under consideration, the rate of occurrence of micro shakes with a spectral peak greater than 1 Hz did not show any significant changes compared to the previous week. With regard to lower frequency events (VLP; spectral peak less than 1 Hz), the decay phase is confirmed, observed from the last decade of December 2021, characterized by a very low rate of occurrence.

Source and graphic : INGV.

Read the article: https://www.ct.ingv.it/index.php/monitoraggio-e-sorveglianza/prodotti-del-monitoraggio/bollettini-settimanali-multidisciplinari/584-bollettino-settimanale-sul-monitoraggio-vulcanico-geochimico-e-sismico-del-vulcano-Vulcano-del-2022-01-11/file

Photo : G. De Astis (INGV-Rome1)

 

Chile , Nevados de Chillan :

Seismicity parameters associated with fracturing processes of rigid materials (type VT) recorded a decrease in the number of events and their associated energy, while events associated with fluid dynamics (type LP and VLP) also recorded a slight decrease in the number of events and energy levels compared to the previous period. There was a slight increase in the number of tremor pulse events (TR type) with a slight decrease in the associated energy levels. Explosive-type (EX-type) events showed a slight increase in quantity and decrease in associated energy levels for the period.
The highest energy VT-type event, with a local magnitude (ML) of 1.7, was located 6.5 km east (E) of the active crater and at a depth of 3 km.

From the analysis of the images provided by the surveillance cameras belonging to OVDAS as well as the satellite images, it was observed that the stop in the advance of the lava flows « L7 » and « L8 » is maintained. On the other hand, there was a contribution of new material in the zone of the active crater but without this generating a clear morphology on the surface due to the intermittence of the contribution or its low intensity.

The explosive activity, during the period evaluated, was generally characterized by a low content of pyroclasts and a dominance of water vapor. However, significant events were recorded on December 24 and 25, with a maximum column height of 1860 m above the emission point and a high pyroclast content.
There was a decrease in the frequency of nocturnal glow episodes, characterized by low-level, low-distribution events, with the exception of the occasional pulses that occurred on December 25.

According to data obtained by the network of GNSS stations installed on the volcano, the transition from a deflationary phase to an inflationary phase is observed, with stations recording an upward trend with rates of 0.5 cm / month, while that inclinometric stations showed variations in direction, these being more evident in stations near the active crater.
Twelve (12) thermal alerts were recorded in the area with a maximum value of 32 MW on December 21, a value considered moderate for this volcano. Radiance anomalies were also detected on December 16, 19, 21, 24, 26, 29 and 31 from Sentinel 2-L2A image analysis.
The DOAS gas measuring equipment recorded a maximum sulfur dioxide (SO2) emission value of 451 t / d for December 19 and 31, while the recorded average emission was 196 t / d. Proof that a decrease in gas emissions continues compared to the previous period, probably linked to a partial obstruction of the emission ducts.

Source : SEGEMAR.

Photo : 24 Horas

 

Italy / Sicily , Etna :

WEEKLY NEWSLETTER, from January 03, 2022 to January 09, 2022 (issue date January 11, 2022)

SUMMARY OF THE STATE OF THE ACTIVITY.

In the light of the surveillance data, it is highlighted:

1) VOLCANOLOGICAL OBSERVATIONS: Degassing activity at variable rate of all the summit craters. Sporadic and weak emissions of very dilute ash from the crater of Bocca Nuova.
2) SEISMOLOGY: Moderate increase in the rate of earthquakes, low energy releases; average amplitude of low-level tremors
3) INFRASOUND: moderate increase in infrasound activity.
4) SOIL DEFORMATION: During the last week, the soil deformation monitoring networks have not recorded any significant changes.
5) GEOCHEMISTRY: SO2 flux at a medium-low level
CO2 flows on the ground recorded by the Etnagas network at average levels.
Partial pressure of dissolved CO2 at values ​​consistent with the seasonal trend.
There is no update on the isotopic ratio of helium in peripheral manifestations (latest data from 16.12.2021 on medium-high levels).
There are no updates for the C / S report.
6) SATELLITE OBSERVATIONS: The thermal activity in the summit area observed by satellite was low.

VOLCANOLOGICAL OBSERVATIONS

During the week under review, the monitoring of the volcanic activity of Mount Etna was carried out through the analysis of images from the INVV surveillance camera network of the Mount Etna Observatory ( INGV-OE) and through remote observations by INGV staff. At the beginning of the week, observations were often made difficult by adverse weather conditions. The period was characterized by variable degassing activity of all summit craters, with sustained degassing activity at Bocca Nuova Crater and a few high-temperature points at Southeast Crater.

Source : INGV

Read the article: https://www.ct.ingv.it/index.php/monitoraggio-e-sorveglianza/prodotti-del-monitoraggio/bollettini-settimanali-multidisciplinari/585-bollettino-settimanale-sul-monitoraggio-vulcanico-geochimico-e-sismico-del-vulcano-Etna-del-2022-01-11/file

Photo : Gio Giusa.

 

New Zealand , Ruapehu :

VOLCANIC ALERT BULLETIN, Wed Jan 12 2022 2:30 PM;

Volcanic Alert Level remains at 1
Aviation Colour Code remains at Green

A recent cluster of earthquakes has occurred beneath Ruapehu’s summit. All monitoring data at Ruapehu indicates that volcanic unrest remains at minor levels. The Volcanic Alert Level at Mt Ruapehu stays at Level 1.

Earthquakes regularly occur in the Tongariro National Park, and towards the southern portion around Ruapehu, we often record them near Waiouru and National Park Village. There are two broad styles of earthquakes at volcanoes: volcanic earthquakes (which includes tremor) that are directly related to the movement of fluids (magma and/or the hydrothermal system), and tectonic earthquakes which result from rocks fracturing (movement on small faults).

From 30 December 2021, we have recorded a sequence of tectonic earthquakes located beneath Ruapehu’s summit area. So far, there have been at least 30 distinct earthquakes in this sequence. When compared to historical records, the number of earthquakes with epicentres closely confined to the summit area, is unusual. While these earthquake clusters are uncommon, none of our monitoring data suggests that the volcano is exhibiting increased levels of activity.

There has been no observable response from other continuous monitoring data such as Crater Lake (Te Wai ā-moe) temperature, lake level, or volcanic tremor. Therefore, our current assessment is that a relatively deep stress release has occurred below the volcano, but this has not affected the volcano’s hydrothermal system.

Our team will be conducting a scheduled gas flight and will sample Ruapehu’s Crater Lake (Te Wai ā-moe) in the coming days, weather permitting.

The Volcanic Alert Level stays at Level 1 which reflects the current level of volcanic unrest. The Volcanic Alert Level should not be used to forecast future activity.

The Aviation Colour Code remains at colour Green.

Mt Ruapehu is an active volcano and has the potential to erupt with little or no warning when in a state of volcanic unrest.

Source : Geonet / Geoff Kilgour Duty Volcanologue

Photo : Bradd Scott / GNSS

May 20, 2021. EN . Italy : Stromboli , La Réunion Island : Piton de la Fournaise , Iceland : Geldingadalur , Chile : Laguna del Maule , Guatemala : Pacaya , Colombia : Nevado de Santa Isabel .

May 20 , 2021.

 

Italy , Stromboli :

PRESS RELEASE ON THE ACTIVITY OF STROMBOLI, May 19, 2021, 15:08 (13:08 UTC)

The National Institute of Geophysics and Volcanology, Osservatorio Etneo, announces that at 12:51 UTC, CCTV footage showed the formation of a large ash cloud that affected the Sciara del Fuoco all the way to the coast.

PRESS RELEASE ON THE ACTIVITY OF STROMBOLI, May 19, 2021, 15:38 (13:38 UTC)

The National Institute of Geophysics and Volcanology, Osservatorio Etneo, announces that from 12:47 UTC an increase in explosive activity was observed from the area of the North crater which at 12:51 produced a pyroclastic flow that there reached the coastline extending into the sea for more than 1 km and producing an ash cloud which reached an estimated height of about 1.5 to 2 km above sea level. Lesser intensity pyroclastics occurred from 1:02 PM UT, producing modest clouds of ash and warm coarse material reaching the shore. The phenomenon is still ongoing.
From 12:51 GMT, a transient of around 0.1 microradians is visible on the inclinometric signal from Timpone del Fuoco.

PRESS RELEASE ON THE ACTIVITY OF STROMBOLI, May 19, 2021, 16:41 (14:41 UTC)

The National Institute of Geophysics and Volcanology, Osservatorio Etneo, announces that a lava flow is underway along the Sciara del Fuoco whose front reaches the coast.
The phenomenon described in the previous press release was repeated with several episodes, of less intensity, until 13:35 UTC. More intense explosive activity was observed during these events. An overflight is underway with the fire brigade helicopter in order to acquire more information on the phenomenon in progress.
In conjunction with the observed volcanic phenomenology, an increase in the seismic trace was recorded starting at 12:47 UTC, which may be associated with the dynamics of pyroclastic flow along the Sciara del Fuoco. In particular, a series of events was recorded (at 12:51, 13:04, 13:09, 13:13 UTC, etc.) clearly visible at the Ginostra ISTR seismic station and at the STR4 station.
The inclinometric signal from Timpone del Fuoco shows some modest transients (around + -0.2 microradians) between 12: 51-12: 55 UTC, between 13: 10-13: 15 UTC and between 13: 51-13: 53 UTC . The GNSS network is currently not available for data transmission problems.

 

PRESS RELEASE ON STROMBOLI ACTIVITY, 19 May 2021, 18:50 (16:50 UTC)

The National Institute of Geophysics and Volcanology, Osservatorio Etneo, announces that following the overflight carried out by INGV staff with the firefighting helicopter, it was observed that the pyroclastic flow, described in the press release No. 5, came from the collapse of the flank of the northern crater (CN). The latter produced a lava overflow that spills along the Sciara del Fuoco until it reaches the coast.
It is also announced that the explosive activity will continue. It should be noted that Stromboli seismic signals (with the exception of ISTR and STR4 stations) have not been available since 2.36pm local time due to data transmission issues reported in the 13:33 UTC press release. The magnitude of the tremor, observable at the 2 stations, is currently at values ​​comparable to those that preceded today’s release No. 4. Regarding the magnitude of the explosion earthquakes, at the ISTR station there is a slight upward trend compared to what was observed before the volcanic phenomenon.
After the previous variations already reported, the Timpone del Fuoco inclinometric signal shows other modest transients of lower intensity. The GNSS network is not yet available.

Other updates will be announced soon.

Source : INGV.

Read the article : ComunicatoSTROMBOLI20210519143351.pdf (ingv.it)

Photos : INGV , Ashàra , Michele Giardulli .

 

La Réunion Island , Piton de la Fournaise :

Press release of May 19, 2021 – 2:00 p.m.

The eruption that started on 04/09/2021 at 7 p.m. (appearance of the tremor) continues. The amplitude of the volcanic tremor (indicator of a surface lava emission) continues its slow decrease that began on May 2.

The images from the OVPF and OVPF / IRT cameras for the last 24 hours that:
– The activity at the two cones is down slightly;
– A strong degassing persists at the level of the two cones;
– the flow of lava at the exit of the eruptive vents, occurs mainly in tunnels up to the upper limit of the large slopes, where resurgences of lava are sometimes visible on the surface;
– the flow front progresses only very slowly in the Grandes Pentes.

Over the past 24 hours, 2 superficial volcano-tectonic earthquakes (between sea level and the surface) have been recorded, located directly above the summit craters.
– The CO2 fluxes in the soil are always increasing in the far field (Plains region).
– The slight inflation trend of the building observed in recent days is confirmed.
– No estimate of lava flow could be established by the HOTVOLC platform (OPGC – Clermont Auvergne University), because the lava flow is now almost entirely in a tunnel linked to the thermal radiation of the flow.
– Practical conditions in the eruptive site area improved during the morning (Figure 3) and deteriorated again in the early afternoon.

Alert level: Alert 2-2

Source et photo : OVPF.

Read the article : https://www.ipgp.fr/sites/default/files/ovpf_20210519_14h00_communique_eruption.pdf

 

Iceland , Geldingadalur :

IMO reported that the fissure eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, continued during 11-18 May. The lava effusion rate was 10.8 meters per second, lower than the 12.9 meters per second rate recorded the week before. Pulsating lava fountains from crater 5, about 7-8 episodes per hour, sent material higher than 300 m.

Very high fountains were visible in Reykjavik. Lava continued to flow into the Meradalir Valley; on 17 May video showed sections of the cone’s rim collapsing into the crater. By 18 May the area of the flow field had grown to 2.06 square kilometers, the total volume erupted was 38 million cubic meters. Authorities directed the construction of earthen barriers to prevent lava flowing into the Nátthaga valley and possibly overtaking Highway 427 (Suðurstrandarvegur) to the S, protecting the road and buried fiberoptic cables. The Aviation Color Code remained at Orange due to the lack of ash and tephra emissions. Authorities warned of increased gas emissions hazards.

Source : GVP

Photo : Volcano chaser / Marc Szeglat

 

Chile , Laguna del Maule :

Special Report on Volcanic Activity (REAV), del Maule region, Laguna del Maule volcanic complex, May 15, 2021, 10:40 p.m. local time (Continental Chile).

The National Service of Geology and Mines of Chile (Sernageomin) publishes the following PRELIMINARY information, obtained thanks to the monitoring equipment of the National Volcanic Monitoring Network (RNVV), processed and analyzed at the Volcanological Observatory of the Southern Andes ( Ovdas):

On May 15 at 19:48 local time (23:48 UTC), monitoring stations installed near the Laguna del Maule volcanic complex recorded a seismic swarm of 156 volcano-tectonic (VT) events, associated with rock fracturing, located 7 km south-southwest of the center of the lagoon.

 

The characteristics of the most important earthquake after its analysis are as follows:
TIME OF ORIGIN: 19:55 local time (23:55 UTC)
LATITUDE: 36.105 ° S
LONGITUDE: 70.565 ° W
DEPTH: 6.3 km
LOCAL MAGNITUDE: 1.8 ML

OBSERVATIONS:
At the time of this report, the seismic activity exhibited sporadic, lower energy VT-type earthquakes.

The volcanic technical alert remains at the Yellow level.

Source : Sernageomin.

Photo : Franco Vera.

 

Guatemala , Pacaya :

SPECIAL VOLCANOLOGICAL BULLETIN, May 19, 2021, 8:45 a.m. local time.

Since May 15, the Pacaya volcano has presented a change in its eruptive pattern, the lava flow active in recent weeks has stopped, the main activity is currently located in the Mackenney crater. This activity consists of periods of constant emission of columns of gas and ash at a height of up to 3,500 meters above sea level (11,483 feet) that move in the direction of the wind. There are also explosions of weak to moderate characteristics which expel ballistic projections to a maximum height of 100 meters above the crater. Ash falls have been reported in the communities of San Francisco de Sales, Concepción El Cedro, Aldea El Patrocinio and San Miguel Petapa.

  Column of ash moving north. Photograph taken by the Agua OVAGU volcano observatory, INSIVUMEH.

This activity is expected to continue for the following days or weeks, so ashfall is expected in the communities around the volcano depending on the wind direction. It is not excluded that periods of high explosiveness will be generated in the coming hours or days and / or the emergence of lava flows on the various sides of the Pacaya volcano.

Source : INSIVUMEH  

Photos : Salamandra house , Insivumeh.

 

Colombia , Nevado de Santa Isabel :

Manizales, May 19, 2021 (09:50 local time)

Subject: Bulletin of extraordinary activity of the Nevado de Santa Isabel volcano. The green activity level is maintained or (IV): Active volcano and stable behavior.

Regarding the monitoring of the activity of the Nevado del Santa Isabel volcano, the COLOMBIAN GEOLOGICAL SERVICE reports that:
As of yesterday, May 18, 2021, at 7:43 p.m. (local time), there has been an increase in seismic activity associated with the fracturing of the rock around the volcanic building of the Nevado de Santa Isabel volcano.

The earthquakes are located on the west-northwest flank of the volcano, at depths between 3.0 and 7.0 km. Over the past few hours, the number of events and their seismic energy have increased. Until the time of publication of this report, there have been three earthquakes with a magnitude greater than 2.0 ML (local magnitude). The maximum magnitude recorded to date is 2.6 ML (local magnitude), corresponding to the earthquake that occurred at 07:00 (local time), located 2.5 km north-northwest of the volcanic structure, at a depth of 3.5 km. It should be noted that this increase is the one with the greatest number of events occurring in the region since December 2017.

It is recommended that the community continue to be attentive to any changes that occur in the activity of the volcano.

Source : Ingeominas .

Photo : masaya experience.

20 Mai 2021. FR. Italie : Stromboli , La Réunion : Piton de la Fournaise , Islande : Geldingadalur , Chili : Laguna del Maule , Guatemala : Pacaya , Colombie : Nevado de Santa Isabel .

20 Mai 2021.

 

Italie , Stromboli :

COMMUNIQUÉ DE PRESSE SUR L’ACTIVITE DE STROMBOLI , 19 Mai 2021, 15:08 (13:08 UTC) 

L’Institut national de géophysique et de volcanologie, Osservatorio Etneo , annonce qu’à 12 h 51 UTC, les images de vidéosurveillance ont montré la formation d’un gros nuage de cendres qui a affecté la Sciara del Fuoco jusqu’à la côte.  

COMMUNIQUÉ DE PRESSE SUR L’ACTIVITE DE STROMBOLI , 19 Mai 2021, 15:38 (13:38 UTC)

L’Institut national de géophysique et de volcanologie, Osservatorio Etneo, annonce qu’à partir de 12h47 UTC, une augmentation de l’activité explosive a été observée à partir de la zone du cratère Nord qui à 12h51 a produit un flux pyroclastique qui y est parvenu jusqu’au littoral s’étendant dans la mer sur plus de 1 km et produisant un nuage de cendres qui a atteint une hauteur estimée d’environ 1,5 à 2 km au dessus du niveau de la mer. D’autres coulées pyroclastiques de moindre intensité se sont produites à partir de 13 h 02 TU, produisant de modestes nuages ​​de cendres et de matières grossières chaudes atteignant le rivage. Le phénomène est toujours en cours.  
À partir de 12h51 TU, un transitoire d’environ 0,1 microradians est visible sur le signal inclinométrique de Timpone del Fuoco.

COMMUNIQUÉ DE PRESSE SUR L’ACTIVITE DE STROMBOLI , 19 Mai 2021, 16:41 (14:41 UTC)

L’Institut national de géophysique et de volcanologie, Osservatorio Etneo, annonce qu’une coulée de lave est en cours le long de la Sciara del Fuoco dont le front atteint la côte.
Le phénomène décrit dans le communiqué de presse précédent s’est répété avec plusieurs épisodes, de moindre intensité, jusqu’à 13h35 UTC. Une activité explosive plus intense a été observée lors de ces événements. Un survol est en cours avec l’hélicoptère des pompiers afin d’acquérir de plus amples informations sur le phénomène en cours.
En conjonction avec la phénoménologie volcanique observée  , une augmentation de la trace sismique a été enregistrée à partir de 12h47 UTC, ce qui peut être associé à la dynamique de l’écoulement pyroclastique le long de la Sciara del Fuoco. En particulier, une série d’événements a été enregistrée (à 12h51, 13h04, 13h09, 13h13 UTC, etc.) clairement visibles à la station sismique Ginostra ISTR et à la station STR4.
Le signal inclinométrique de Timpone del Fuoco montre quelques transitoires modestes (autour de + -0,2 microradians) entre 12: 51-12: 55 UTC, entre 13: 10-13: 15 UTC et entre 13: 51-13: 53 UTC. Le réseau GNSS n’est actuellement pas disponible pour les problèmes de transmission de données .

 

COMMUNIQUÉ DE PRESSE SUR L’ACTIVITE DE STROMBOLI , 19 Mai 2021, 18:50 (16:50 UTC)

L’Institut National de Géophysique et Volcanologie, Osservatorio Etneo, annonce qu’à la suite du survol effectué par le personnel d’INGV avec l’hélicoptère des pompiers, il a été observé que l’écoulement pyroclastique, décrit dans le communiqué de presse n ° 5, provenait de l’effondrement du flanc du cratère nord (CN). Ce dernier a produit un débordement de lave qui se déverse le long de la Sciara del Fuoco jusqu’à ce qu’il atteigne la côte.
Il est également annoncé que l’activité explosive se poursuit. Il est à noter que les signaux sismiques de Stromboli (à l’exception des stations ISTR et STR4) ne sont pas disponibles depuis 14h36 heure locale en raison des problèmes de transmission de données signalés dans le communiqué de presse de 13h33 UTC. L’amplitude du tremor, observable aux 2 stations, se situe actuellement à des valeurs comparables à celles qui ont précédé le communiqué n ° 4 d’aujourd’hui. En ce qui concerne l’ampleur des séismes d’explosion, à la station ISTR il y a une légère tendance à la hausse par rapport à ce qui a été observé avant le phénomène volcanique.
Après les variations précédentes déjà communiquées, le signal inclinométrique de Timpone del Fuoco montre d’autres transitoires modestes de moindre intensité. Le réseau GNSS n’est actuellement pas encore disponible.

D’autres mises à jour seront communiquées rapidement.

Source : INGV.

Lire l’article : ComunicatoSTROMBOLI20210519143351.pdf (ingv.it)

Photos : INGV , Ashàra , Michele Giardulli .

 

La Réunion , Piton de la Fournaise :

Communiqué du 19 Mai 2021 – 14h00 .

L’éruption débutée le 09/04/2021 à 19h (apparition du trémor) se poursuit. L’amplitude du trémor volcanique (indicateur d’une émission de lave en surface) poursuit sa lente décroissance initiée depuis le 2 mai.

Les images des caméras de l’OVPF et de l’OVPF / IRT de ces dernières 24 heures montrent que:
– L’activité au niveau des deux cônes est en légère diminution;
– Un fort dégazage persiste au niveau des deux cônes  ;
– l’écoulement de la lave à la sortie des bouches éruptives, se fait essentiellement en tunnels et ce jusqu’à la limite supérieure des grandes pentes, où des résurgences de lave sont parfois visibles en surface;
– le front de coulée ne progresse que très lentement dans les Grandes Pentes.

 Sur les dernières 24 heures, 2 séismes volcano-tectoniques superficiels (entre le niveau de la mer et la surface) ont été enregistrés, localisés à l’aplomb des cratères sommitaux.
– Les flux de CO2 dans le sol sont toujours en hausse en champ lointain (région des Plaines).
– La légère tendance à l’inflation de l’édifice constatée ces derniers jours, se vérifie.
– Aucune estimation de débit de lave n’a pu être établie par la plateforme HOTVOLC (OPGC – université Clermont Auvergne), car l’écoulement de la lave est désormais en quasi-totalité en tunnel lié au rayonnement thermique de la coulée.
– Les conditions pratiques dans la zone du site éruptif se sont améliorées en cours de matinée (Figure 3) et se dégradent à nouveau en début d’après-midi.

Niveau d’alerte: Alerte 2-2

Source et photo : OVPF.

Lire l’articlehttps://www.ipgp.fr/sites/default/files/ovpf_20210519_14h00_communique_eruption.pdf

 

Islande , Geldingadalur :

L’OMI a signalé que l’éruption de fissure dans la partie Ouest du système volcanique Krýsuvík-Trölladyngja, près de Fagradalsfjall sur la péninsule de Reykjanes, s’est poursuivie du 11 au 18 mai. Le taux d’épanchement de lave était de 10,8 mètres par seconde, inférieur au taux de 12,9 mètres par seconde enregistré la semaine précédente. Les fontaines de lave pulsées du cratère 5, environ 7 à 8 épisodes par heure, envoyaient du matériel à plus de 300 m.

Des fontaines très hautes étaient visibles à Reykjavik. La lave a continué à couler dans la vallée de Meradalir le 17 mai, une vidéo montrait des sections du bord du cône s’effondrant dans le cratère. Le 18 mai, la superficie du champ d’écoulement était passée à 2,06 kilomètres carrés, le volume total en éruption était de 38 millions de mètres cubes. Les autorités ont dirigé la construction de barrières en terre pour empêcher la lave de s’écouler dans la vallée de Nátthaga et éventuellement de dépasser l’autoroute 427 (Suðurstrandarvegur) vers le Sud, protégeant la route et les câbles à fibres optiques enterrés. Le code couleur de l’aviation est resté à Orange en raison du manque d’émissions de cendres et de téphra. Les autorités ont mis en garde contre l’augmentation des risques liés aux émissions de gaz.

Source : GVP

Photo : Volcano chaser / Marc Szeglat

 

Chili , Laguna del Maule :

Rapport spécial sur l’activité volcanique (REAV), région del Maule, complexe volcanique Laguna del Maule, 15 mai 2021, 22 h 40 heure locale (Chili continental).

Le Service National de Géologie et des Mines du Chili (Sernageomin) publie les informations PRÉLIMINAIRES suivantes, obtenues grâce à l’équipement de surveillance du Réseau National de Surveillance Volcanique (RNVV), traitées et analysées à l’Observatoire Volcanologique des Andes du Sud (Ovdas):

Le 15 mai à 19 h48 heure locale (23h48 UTC), les stations de surveillance installées à proximité du complexe volcanique Laguna del Maule ont enregistré un essaim sismique de 156 évènements de type volcano-tectoniques (VT) , associés à la fracturation de roches, localisés à 7 Km au Sud-Sud-Ouest du centre de la lagune.

 

Les caractéristiques du séisme le plus important après son analyse sont les suivantes:
HEURE D’ORIGINE: 19:55 heure locale (23:55 UTC)
LATITUDE: 36.105 ° S
LONGITUDE : 70,565 ° W
PROFONDEUR: 6,3 km
MAGNITUDE LOCALE : 1,8 ML

OBSERVATIONS:
Au moment de ce rapport , l’activité sismique présentait des séismes de type VT sporadiques de plus faible énergie .

L’alerte technique volcanique reste au niveau Jaune .

Source : Sernageomin.

Photo : Franco Vera.

 

Guatemala , Pacaya :

BULLETIN SPÉCIAL VOLCANOLOGIQUE, 19 mai 2021, 08h45 heure locale.

Depuis le 15 mai, le volcan Pacaya a présenté un changement dans son schéma éruptif, la coulée de lave active ces dernières semaines s’est arrêtée, l’activité principale est actuellement située dans le cratère Mackenney. Cette activité se compose de périodes d’émission constante de colonnes de gaz et de cendres à une hauteur pouvant atteindre 3500 mètres au-dessus du niveau de la mer (11483 pieds) qui se déplacent dans la direction du vent . On note aussi des explosions de caractéristiques faibles à modérées qui expulsent des projections balistique à une hauteur maximale de 100 mètres au-dessus du cratère. Il a été signalé des chutes de cendres dans les communautés de San Francisco de Sales, Concepción El Cedro, Aldea El Patrocinio et San Miguel Petapa.


Fig. No. 1: Colonne de cendres se déplaçant vers le nord. Photographie prise par l’observatoire du volcan Agua OVAGU, INSIVUMEH.

On s’attend à ce que cette activité se poursuive pendant les jours ou semaines suivants, de sorte que des chutes de cendres sont attendues dans les communautés autour du volcan en fonction de la direction du vent. Il n’est pas exclu que des périodes de forte explosivité soient générées dans les prochaines heures ou prochains jours et / ou l’émergence de coulées de lave sur les différents flancs du volcan Pacaya.

Source : INSIVUMEH  

Photos : Salamandra house , Insivumeh.

 

Colombie , Nevado de Santa Isabel :

Manizales, 19 mai 2021 (09:50 Heure locale)

Objet: Bulletin d’activité extraordinaire du volcan Nevado de Santa Isabel. Le niveau vert d’activité est maintenu ou (IV): Volcan actif et comportement stable.

Concernant le suivi de l’activité du volcan Nevado del Santa Isabel, le SERVICE GÉOLOGIQUE COLOMBIEN rapporte que:
Depuis hier 18 mai 2021, à 19 h 43 (heure locale), il y a eu une augmentation de l’activité sismique associée à la fracturation de la roche autour du bâtiment volcanique du volcan Nevado de Santa Isabel.

Les tremblements de terre sont situés sur le flanc Ouest-Nord-Ouest du volcan, à des profondeurs comprises entre 3,0 et 7,0 km. Au cours des dernières heures, le nombre d’événements et leur énergie sismique ont augmenté. Jusqu’au moment de la publication de ce rapport, il y a eu trois tremblements de terre d’une magnitude supérieure à 2,0 ML (magnitude locale). La magnitude maximale enregistrée à ce jour est de 2,6 ML (magnitude locale), correspondant au séisme survenu à 07h00 (heure locale), situé à 2,5 km au Nord-Nord-Ouest de la structure volcanique, à une profondeur de 3,5 km. Il est à noter que cette augmentation est celle avec le plus grand nombre d’événements survenus dans la région depuis décembre 2017.

Il est recommandé que la communauté continue d’être attentive à tout changement qui se produit dans l’activité du volcan.

Source : Ingeominas .

Photo : masaya experience.