October 21 , 2020. EN . Italy / Sicily : Etna , Italy : Stromboli , Iceland : Reykjanes Peninsula , Kamchatka : Karymsky , Colombia : Doña Juana / Las Ánimas .

October 21 , 2020.



Italy / Sicily , Etna :

Weekly Bulletin, October 12, 2020 – October 18, 2020
(issue date 20 October 2020)


In the light of surveillance data, it is highlighted:
1) VOLCANOLOGICAL OBSERVATIONS: Variable strombolian activity with emission of ash at the New Southeast Crater; Strombolian activity within the deep crater at the northeast crater; degassing activity of the craters of Voragine and Bocca Nuova.
2) SEISMOLOGY: low seismic activity of fracturing; stationarity of the parameters of the volcanic tremor mainly on the average values.
3) INFRASOUND: Modest infrasound activity.
4) DEFORMATIONS: The Etna soil deformation monitoring networks have not shown significant changes over the past week
5) GEOCHEMISTRY: The flow of SO2 occurs at a medium-low level.
HCl flow occurs at an average level.
6) SATELLITE OBSERVATIONS: The thermal activity in the summit area is at a low level.



The monitoring of the volcanic activity of Etna, during the week in question, was carried out by analyzing the images of the network of surveillance cameras of the INGV, Osservatorio Etneo (INGV-OE), and through various observations made by INGV-OE staff. Bad weather conditions have repeatedly limited the observation of eruptive phenomena.

During the week under review, the activity of the summit craters of Etna continued in a manner similar to what had been observed in the previous weeks. This activity consisted of episodic Strombolian activity with periodic ash emissions at the New Southeast Crater (NSEC), deep intracrater Strombolian activity at the Northeast Crater (NEC) and degassing at the Voragine craters ( VOR) and Bocca Nuova (BN).
In particular, the “saddle cone” of the New Southeast Crater continued its episodic Strombolian activity, sometimes accompanied by modest emissions of ash. This activity has continued since mid-July without significant changes. During the phases of more intense activity, the pyroclastic products launched from the mouth fell on the external faces of the cone.
The intracrater Strombolian activity of the various vents at the bottom of the Northeast crater continues, without significant changes. Some nights, the gleams of the North-East crater were visible on the images of the surveillance cameras of the INGV-OE.
At the level of the Voragine and Bocca Nuova craters, activity was limited to degassing.


Volcanic tremor:
The temporal trend of the mean amplitude of the volcanic tremor showed large fluctuations, mainly at an average level, throughout the week and rarely such fluctuations reached a high level. The source of the tremor was constantly located in the New Southeast Crater (NSEC) area, at a depth of about 2900-3000 meters above mean sea level

Source : INGV.

Read the article http://www.ct.ingv.it/index.php/monitoraggio-e-sorveglianza/prodotti-del-monitoraggio/bollettini-settimanali-multidisciplinari/381-bollettino-settimanale-sul-monitoraggio-vulcanico-geochimico-e-sismico-del-vulcano-etna20201020/file

Photos : Gio Giusa.


Italy , Stromboli :

Weekly Bulletin, October 12, 2020 – October 18, 2020
(issue date 20 October 2020)


In the light of surveillance data, it is highlighted:
1) VOLCANOLOGICAL OBSERVATIONS: Normal explosive volcanic activity of Strombolian type at low and medium-low levels (4-10 events / h) and with a medium-low intensity in the North zone and medium-high in the Center-South zone.
2) SEISMOLOGY: The seismological parameters do not show significant variations.
4) DEFORMATIONS: The island’s soil deformation monitoring networks did not show any significant changes to report for the period under review.
5) GEOCHEMISTRY: Medium-low SO2 flux.
6) SATELLITE OBSERVATIONS: The thermal activity in the summit area is at a low level.

Stromboli at nightfall on September 2, 2020, activity seen by the northern ridge of the Sciara del Fuoco at about 700 m. The photos were taken by Alessandro Gattuso (INGV-Palermo).


In the period under observation, the eruptive activity of Stromboli was characterized by the analysis of the images recorded by the surveillance cameras of the INGV-OE located at an altitude of 190 m, in Punta dei Corvi and at 400 m from ‘altitude.

In the area of ​​the North crater, the N1 crater, with three emission points, produced explosions of low intensity (less than 80 m high) to medium (less than 150 m high) emitting coarse materials (lapilli and bombs) sometimes mixed fine materials (ash). Vent N2, with two emission points, showed mainly low to medium intensity explosive activity, emitting coarse material mixed with fine material. The average frequency of the explosions varied from 3 to 9 events / h.
In the Center-South zone, the explosions mainly emitted fine materials sometimes mixed with coarse materials with a medium-high intensity (the products emitted often exceeded 250 m in height).
The low explosive activity showed a maximum frequency of 1 event / h.

The amplitude of the volcanic tremor had generally low values, with some oscillations on medium-low values.

Source : INGV.

Read the article : http://www.ct.ingv.it/index.php/monitoraggio-e-sorveglianza/prodotti-del-monitoraggio/bollettini-settimanali-multidisciplinari/382-bollettino-settimanale-sul-monitoraggio-vulcanico-geochimico-e-sismico-del-vulcano-Stromboli20201020/file

Photo : Alessandro Gattuso (INGV-Palerme).


Iceland ,  Reykjanes Peninsula :

M5.6 at the Reykjanes peninsula , The largest earthquake measured since 2003, October 20 , 2020.

At 13:43 today (20th of October) an earthquake of M5.6 occurred in Núpshlíðarháls, about 5 km west of the geothermal area in Seltún on the Reykjanes peninsula. The earthquake was felt widely around the country, especially the southern part of the Reykjanes peninsula and in the capital area, which is some 25 km from the epicenter. At this time over 250 aftershocks have been detected, the largest ones in the period between 15:27 and 15:32. The largest was of M4.1, other earthquakes between 3.0 and 3.8. There are no signs of volcanic unrest in the area.

The earthquake today is the largest earthquake measured in the Reykjanes peninsula since 2003.

“There is an active long-term process ongoing in the area and we can expect that there will be more earthquakes in the coming hours that will be felt all the way to the capital area”, says Kristín Jónsdóttir, Earthquake hazards coordinator at the Icelandic Met Office, in an interview with RÚV today.

A great deal of earthquake activity has been ongoing in the peninsula in 2020. Earthquakes of M5 were recorded in July this year, by Fagradalsfjall, just west of where the epicenter of the M5.6 earthquake today was. Earthquake history of the Reykjanes Peninsula shows that large earthquakes have occurred in the past in connection with large earthquake swarms. Therefore, there is the possibility of large aftershocks occurring in this swarm. Largest earthquakes in the area can possibly reach M5.5-6. Those types of earthquakes can cause damages within the capital area.

The current earthquake activity in the Reykjanes peninsula that started today can cause increased risk of rockfall. Travellers are urged to show caution beneath steep hills.

Source : Vedur is .


Kamchatka , Karymsky :


Issued: October 21 , 2020
Volcano: Karymsky (CAVW #300130)
Current aviation colour code: ORANGE
Previous aviation colour code: green
Source: KVERT
Notice Number: 2020-189
Volcano Location: N 54 deg 2 min E 159 deg 26 min
Area: Kamchatka, Russia
Summit Elevation: 4874.08 ft (1486 m)

Karymsky volcano fumarole activity on October 13, 2020.

Volcanic Activity Summary:
According to data by AMC Elizovo (from pilots), explosions sent ash up to 4 km a.s.l. about 0230 UTC on 21 October. Ash plume continues to drift to the south-east of the volcano. Last esplosions of Karymsky was noted on 29 July, 2020. KVERT continues to monitor the volcano.
A moderate eruptive activity of the volcano continues. Ash explosions up to 19,700-23,000 ft (6-7 km) a.s.l. could occur at any time. Ongoing activity could affect low-flying aircrafts.

Volcanic cloud height:
13120-16400 ft (4000-5000 m) AMSL Time and method of ash plume/cloud height determination: 20201021/0220Z – Himawari-8

Other volcanic cloud information:
Distance of ash plume/cloud of the volcano: 25 mi (40 km)
Direction of drift of ash plume/cloud of the volcano: SE / azimuth 134 deg
Time and method of ash plume/cloud determination: 20201021/0220Z – Himawari-8
Start time of explosion and how determined: 20201021/0215Z – Satellite data

Source : Kvert.

Photo : D. Melnikov. IVS FEB RAS, KVERT.


Colombia , Doña Juana / Las Ánimas :

Activity bulletin of the Doña Juana and Las Ánimas volcanoes

Volcanic activity continues at: GREEN LEVEL ■ (IV): ACTIVE VOLCANO AND STABLE BEHAVIOR.

From the monitoring of the activity of the VOLCANOES DOÑA JUANA Y LAS ÁNIMAS, the COLOMBIAN GEOLOGICAL SERVICE (SGC) reports that:

From the publication of the bulletin of extraordinary activities of the volcanoes Doña Juana and Las Ánimas (October 16), a daily peak of maximum occurrence of 272 events was highlighted on October 17; After that and until now, there has been a considerable decrease in the occurrence and the energy released, today until 4.30 p.m. 15 earthquakes. It is pointed out that since October 13, there has been an accumulation of 625 events.


Most of these earthquakes are associated with rock fractures, and are preferably located southwest of the Las Ánimas volcano, at epicentral distances of between 2 and 5 km from its summit, at depths of between 3 and 6 km (reference level 4200 m), with magnitudes less than 3.2 on the Richter scale. No relevant change was observed in the other parameters of the monitoring carried out on these volcanoes.

The COLOMBIAN GEOLOGICAL SERVICE remains attentive to the evolution of the volcanic phenomenon and will continue to report the observed changes in due course.

Source et photo : SGC


October 18, 2020. EN . Indonesia : Merapi , Colombia : Doña Juana / Las Ánimas , Guatemala : Fuego , Iceland : Seismicity .

 October 18 , 2020. 


Indonesia , Merapi :

Mount Merapi Activity Report, October 9-15, 2020

The weather around Mount Merapi is generally sunny in the morning and at night, while the afternoon until evening is foggy. There is white smoke, thin to thick with low pressure. A maximum smoke height of 75m was observed from the Mount Merapi observation post in Jrakah on October 15, 2020 at 5:40 a.m. WIB.
Morphological analysis of the crater area based on photos of the southeast sector showed no change in the morphology of the dome. The volume of the lava dome based on measurements using aerial photos with drones on July 26, 2020 is 200,000 m3.

This week, the seismicity of Mount Merapi was recorded with:
56 emissions earthquakes (DG),
41 shallow volcanic earthquakes (VTB),
31 multiphase earthquakes (MP),
5 low frequency earthquakes (LF),
67 avalanche earthquakes (RF),
10 tectonic earthquakes (TT).
The seismic intensity this week is higher than last week.

The deformation of Mount Merapi which was monitored using EDM this week showed a shortening rate of 1 cm / day.

Rain and lahars
This week there was rain at Mount Merapi Observation Post with the highest rainfall intensity of 78mm / hour for 30 minutes at Kaliurang Post on October 15, 2020. There was no report lava or additional flow from the rivers flowing down from Mount Merapi.

Based on the results of visual and instrumental observations, it is concluded that:
1. The lava dome is currently in stable condition.
2. The volcanic activity of Mount Merapi is still quite high and is within the “WASPADA” activity level.

Source : BPPTKG .

Photo : via Anette Selau


Colombia , Doña Juana / Las Ánimas :

Bulletin of extraordinary activity of the Doña Juana and Las Ánimas volcanoes
Volcanic activity continues at: GREEN LEVEL ■ (IV): ACTIVE VOLCANO AND STABLE BEHAVIOR.

From the monitoring of the activity of VOLCANOES DOÑA JUANA and LAS ÁNIMAS, the COLOMBIAN GEOLOGICAL SERVICE (SGC) informs that:

From October 13, 2020 until the time of publication of this bulletin, there has been a significant increase in the seismic occurrence and the energy released by earthquakes associated with rock fracturing, cataloged as Volcano -Tectonics  types (VT); counting until 5:00 p.m. 229 events, including 141 registered today.

With an altitude of 4300 meters above sea level, Las Ánimas is located approximately 11 km northeast of the Doña Juana volcano and 12 km southwest of the Petacas volcano.

Most of these earthquakes were preferentially located southwest of the Las Ánimas volcano, at epicentral distances of between 2 and 4 km from its summit, with depths of between 3 and 5 km (reference level 4200 m of altitude) and magnitudes less than 3.2 on the Richter scale. The occurrence of three earthquakes reported as felt by the inhabitants of the villages of El Troje and Las Ánimas of the municipality of La Cruz stands out, which were recorded at 2:46 a.m., 6:44 a.m. and 9:45 a.m. today, with magnitudes of M3.0, M3.2 and M2.4, respectively. No change was observed in the other parameters of the monitoring of these volcanoes.

This SE looking photo of Doña Juana was taken during aerial surveys on 12 March 2007. The town of La Cruz appears in the foreground, ~13 km W of the volcanic edifice (on the skyline). Courtesy of INGEOMINAS.

Similar seismic activity occurred between August and October 2010, when nearly 1,000 VT-type earthquakes with a maximum magnitude of M2.7 were recorded, several of which were felt and which also generated landslides. land in some areas, especially in the Montoso mountain near the Doña Juana volcano.

The COLOMBIAN GEOLOGICAL SERVICE continues to be attentive to the evolution of the volcanic phenomenon and will continue to report the observed changes in due course.

The forested Doña Juana stratovolcano contains two calderas, breached to the NE and SW. The summit of the andesitic-dacitic volcano is comprised of a series of post-caldera lava domes. The older caldera, open to the NE, formed during the mid-Holocene, accompanied by voluminous pyroclastic flows. The younger caldera contains the active central cone. The only historical activity took place during a long-term eruption from 1897-1906, when growth of a summit lava dome was accompanied by major pyroclastic flows.

Source : SGC. GVP.

Photos : Wikipedia / Noslenb9 , Ingeominas.


Guatemala , Fuego :


Activity type: Vulcanian
Morphology: composite stratovolcano
Geographical location: 14 ° 28’54˝Latitude N; 90 ° 52’54˝Longitude W.
Height: 3763 meters above sea level.

LAHAR in the LAS LAJAS and HONDA ravines.
At 3:20 p.m. (local time) the descent of weak to moderate lahars was recorded in the Las Lajas and Honda ravines, tributaries of the Guacalate river, located to the South-East of the volcano.

The seismic network of INSIVUMEH located on the Fuego volcano, records an increase in the amplitude of the seismic signal as shown by the seismogram of the FG13 station. Heavy rains in the upper part of the ravines of the volcanic complex generate the descent of weak to moderate lahars. These can carry tree branches and volcanic material such as ash and boulders 1 to 2 meters in diameter that cause the ground to vibrate. If the rain persists, the generation of more lahars in these or other ravines of the volcanic complex is not excluded.

Source : Insivumeh .

Photo : Caroline Sarrazin , Rés-EAUx .


Iceland , Seismicity :

Yesterday evening at 22:02 an earthquake M3.3 occurred 1.5 km NW of Húsavík. The earthquake was felt in the surrounding area. Several smaller earthquakes have followed. Uncertainty phase is still in effect due to earthquakes in North Iceland by Civil Protection.

Around 1200 earthquakes were located by the IMO¿s automatic SIL seismic network this week, twice as many as last week then around 570 earthquakes were located. Over 950 have been manually located. The increase in activity is largely explained by an earthquake swarm in the Húsavík-Flatey fault, but the swarm that has been ongoing with breaks in the area since June started up again on 5. October with around 650 earthquakes detected there this week. Seven earthquakes larger than M3 were located in the swarm with the largest M4.1 at 05:47 on 6. October. That was also the largest earthquake of the week. The other six earthquakes larger than M3 were also detected the same day. The largest earthquakes were felt widely in the North of Iceland. More activity than previous week was detected in most areas compared to last week. Two earthquakes were located in Hekla volcano, five in Grímsvötn and two in Bárðarbunga.

Source : Vedur IS

18 Octobre 2020. FR . Indonésie : Merapi , Colombie : Doña Juana / Las Ánimas , Guatemala : Fuego , Islande : Sismicité .

18 Octobre 2020. 


Indonésie , Merapi :

Rapport d’activité du mont Merapi , 9-15 octobre 2020

Le temps autour du mont Merapi est généralement ensoleillé le matin et la nuit, tandis que l’après-midi jusqu’au soir est brumeuse . On note une fumée blanche, d’épaisseur faible à épaisse avec une faible pression. Une hauteur de fumée maximale de 75 m a été observée depuis le poste d’observation du mont Merapi de Jrakah le 15 octobre 2020 à 05h40 WIB.
L’analyse morphologique de la zone du cratère basée sur des photos du secteur Sud-Est n’a montré aucun changement dans la morphologie du dôme. Le volume du dôme de lave basé sur des mesures utilisant des photos aériennes avec des drones le 26 juillet 2020 est de 200000 m3.

Cette semaine, la sismicité du mont Merapi a été enregistrée avec :
56 tremblements de terre d’émissions (DG),
41 tremblements de terre volcaniques peu profonds (VTB),
31 séismes multiphases (MP),
5 tremblements de terre à basse fréquence (LF),
67 tremblements de terre d’avalanches (RF),
10 tremblements de terre tectoniques (TT).
L’intensité sismique cette semaine est plus élevée que la semaine dernière.

La déformation du mont Merapi qui a été surveillée à l’aide de l’EDM cette semaine a montré un taux de raccourcissement de 1 cm / jour.

Pluie et lahars
Cette semaine, il y a eu de la pluie au poste d’observation du mont Merapi avec la plus forte intensité de pluie de 78 mm / heure pendant 30 minutes au poste de Kaliurang le 15 octobre 2020. Il n’y a eu aucun rapport de lave ou d’écoulement supplémentaire des rivières qui descendent du mont Merapi.

Sur la base des résultats des observations visuelles et instrumentales, il est conclu que:
1. Le dôme de lave est actuellement dans un état stable.
2. L’activité volcanique du mont Merapi est encore assez élevée et se situe dans le niveau d’activité «WASPADA».

Source : BPPTKG .

Photo : via Anette Selau


Colombie , Doña Juana / Las Ánimas :

Bulletin d’activité extraordinaire des volcans Doña Juana et Las Ánimas
L’activité volcanique se poursuit au: NIVEAU VERT ■ (IV): VOLCAN ACTIF ET COMPORTEMENT STABLE.

À partir du suivi de l’activité des VOLCANS DOÑA JUANA et LAS ÁNIMAS, le SERVICE GÉOLOGIQUE COLOMBIEN (SGC) informe que:

Depuis le 13 octobre 2020 jusqu’au moment de la publication de ce bulletin, il y a eu une augmentation significative de l’occurrence sismique et de l’énergie libérée par les tremblements de terre associés à la fracturation de roche, catalogués comme types Volcano-Tectoniques (VT); comptant jusqu’à 17h00 229 événements, dont 141 enregistrés aujourd’hui.

Avec une altitude de 4300 mètres au-dessus du niveau de la mer, Las Ánimas est situé à environ 11 km au Nord-Est du volcan Doña Juana et à 12 km au Sud-Ouest du volcan Petacas.

La plupart de ces tremblements de terre étaient préférentiellement situés au Sud-Ouest du volcan Las Ánimas, à des distances épicentrales comprises entre 2 et 4 km de son sommet, avec des profondeurs comprises entre 3 et 5 km (niveau de référence 4200 m d’altitude) et des magnitudes inférieures à 3,2 sur l’échelle de Richter. La survenue de trois tremblements de terre signalés comme ressentis par les habitants des villages d’El Troje et de Las Ánimas de la municipalité de La Cruz se démarque, qui ont été enregistrés à 2 h 46, 6 h 44 du matin et 9 h 45  aujourd’hui, avec des magnitudes de M3,0, M3,2 et M2,4, respectivement. Aucun changement n’a été observé dans les autres paramètres de la surveillance de ces volcans.

Cette photo orientée au Sud-Est du Doña Juana a été prise lors de relevés aériens le 12 mars 2007. La ville de La Cruz apparaît au premier plan, à environ 13 km à l’ouest de l’édifice volcanique (sur l’horizon). Gracieuseté de INGEOMINAS.

Une activité sismique similaire s’est produite entre août et octobre 2010, lorsque près de 1000 tremblements de terre de type VT d’une magnitude maximale de M2,7 avaient été enregistrés, dont plusieurs avaient été ressentis et qui avaient également généré des glissements de terrain dans certains secteurs, en particulier dans la montagne Montoso près du volcan Doña Juana.

Le SERVICE GÉOLOGIQUE COLOMBIEN continue d’être attentif à l’évolution du phénomène volcanique et continuera à rendre compte des changements observés en temps opportun.

Le stratovolcan boisé Doña Juana contient deux calderas, percées au Nord-Est et au Sud-Ouest. Le sommet du volcan andésitique-dacitique est composé d’une série de dômes de lave post-caldeira. La caldeira plus ancienne, ouverte sur le Nord-Est, s’est formée au milieu de l’Holocène, accompagnée de volumineuses coulées pyroclastiques. La caldeira plus jeune contient le cône central actif. La seule activité historique a eu lieu lors d’une éruption à long terme de 1897 à 1906, lorsque la croissance d’un dôme de lave sommital était accompagnée de coulées pyroclastiques majeures.

Source : SGC. GVP.

Photos : Wikipedia / Noslenb9 , Ingeominas.


Guatemala , Fuego :


Type d’activité: Vulcanienne
Morphologie: stratovolcan composite
Situation géographique: 14 ° 28’54˝Latitude N; 90 ° 52’54˝Longitude W.
Hauteur: 3763 mètres d’altitude.

LAHAR dans les ravins LAS LAJAS et HONDA .
A 15h20 (heure locale) la descente de lahars faibles à modérés a été enregistrée dans les ravins Las Lajas et Honda, affluents de la rivière Guacalate, situés au Sud-Est du volcan.

Le réseau sismique de l’INSIVUMEH situé sur le volcan Fuego, enregistre une augmentation de l’amplitude du signal sismique comme le montre le sismogramme de la station FG13. Les fortes pluies dans la partie supérieure des ravins du complexe volcanique génèrent la descente de lahars faibles à modérés. Ceux-ci peuvent transporter des branches d’arbres et des matériaux volcaniques tels que des cendres et des blocs de 1 à 2 mètres de diamètre qui font vibrer le sol. Si la pluie persiste, la génération de plus de lahars dans ces ravins ou dans d’autres du complexe volcanique n’est pas exclue.

Source : Insivumeh .

Photo : Caroline Sarrazin , Rés-EAUx .


Islande , Sismicité :

Hier soir à 22h02, un tremblement de terre de M3.3 s’est produit à 1,5 km au Nord-Ouest de Húsavík. Le tremblement de terre a été ressenti dans les environs. Plusieurs petits tremblements de terre ont suivi. La phase d’incertitude de la protection civile est toujours en vigueur en raison des tremblements de terre dans le Nord de l’Islande  .

Environ 1200 tremblements de terre ont été localisés par le réseau sismique automatique SIL de l’OMI cette semaine, deux fois plus que la semaine dernière, ou environ 570 séismes avaient été localisés. Plus de 950 ont été localisés manuellement. L’augmentation de l’activité s’explique en grande partie par un essaim de tremblements de terre dans la faille Húsavík-Flatey, mais l’essaim qui se poursuit avec des ruptures dans la zone depuis juin a redémarré le 5 octobre avec environ 650 tremblements de terre détectés cette semaine là. Sept tremblements de terre plus grands que M3 ont été localisés dans l’essaim avec le plus grand à M4.1 à 05h47 le 6 octobre. C’était également le plus grand tremblement de terre de la semaine. Les six autres tremblements de terre supérieurs à M3 ont également été détectés le même jour. Les plus grands tremblements de terre ont été largement ressentis dans le Nord de l’Islande. Plus d’activité que la semaine précédente a été détectée dans la plupart des régions par rapport à la semaine dernière. Deux tremblements de terre ont été localisés sur le volcan Hekla, cinq sur le Grímsvötn et deux sur le Bárðarbunga.

Source : Vedur IS