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Earth of fire

Actualité volcanique, Articles de fond sur étude de volcan, tectonique, récits et photos de voyage

sismologia

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Merapi - pyroclastic flow detaching under the cloud cover on 02.25.2021 / 4:55 p.m. - photo PVMBG

Merapi - pyroclastic flow detaching under the cloud cover on 02.25.2021 / 4:55 p.m. - photo PVMBG

In Merapi, in activity level 3 / siaga, the seismicity is characterized on February 25 by:

- Two earthquakes related to pyroclastic flows, respectively at 16:52 WIB and 18:42 WIB, with an amplitude of 37 and 51 mm and an earthquake duration of 115 and 175 seconds. They moved for 1500 m and 1900 m in a south-westerly direction.


- 198 collapse earthquakes, with an amplitude of 3-58 mm and a length of 9-188 seconds of the earthquake.
- 2 emission earthquakes, with an amplitude of 8 to 13 mm and the earthquake lasted 11 to 14 seconds.
- 1 hybrid / multiphase earthquake.

The precautions to be taken and the prohibited areas remain unchanged

 

Source: BPPTKG

Merapi - seismicity of the last week on 25.02.2021 - Doc.BPPTKG

Merapi - seismicity of the last week on 25.02.2021 - Doc.BPPTKG

During the last 24 hours, the Taal volcano network has recorded one hundred and thirteen (113) episodes of volcanic tremor lasting from one to thirty-four minutes.

Despite this, only weak steam-laden plumes were emitted by fumarole activity at the vents of the main crater. Elevated temperatures of 74.6 ° C and a pH of 1.59 were last measured from the main crater lake on February 18 and 12, 2021, respectively. The ground deformation parameters of the continuous electronic tilt on the island of the volcano have recorded slight deflation around the main crater since October 2020 but overall, very slow and steady inflation of the Taal region was recorded by continuous GPS data after the eruption.

Alert level 1 (abnormal) is maintained on the Taal volcano. DOST-PHIVOLCS reminds the public that at Alert Level 1, sudden steam or phreatic explosions, volcanic earthquakes, minor ash falls and fatal accumulations or expulsions of volcanic gas can occur and threaten areas of the volcanic island of Taal (TVI). DOST-PHIVOLCS strongly recommends that entry into TVI, the permanent danger zone of Taal or PDZ, especially around the main crater and Daang Kastila fissure, remain strictly prohibited.

 

Source: Phivolcs

Taal - fumaroles on voolcanic island - photo archives Philstar / Ed Jones

Taal - fumaroles on voolcanic island - photo archives Philstar / Ed Jones

The Pacaya presents an essentially effusive activity on February 25, with the lengthening of the lava flow on the southern flank between 1000 and 1680 m.

Moderate to strong strombolian explosive activity is recorded sporadically.

Degassing columns, white to azure, 200 to 800 m high. above the crater are observed, moving south and over-west

 

Source: Insivumeh

Pacaya - lava flow of 02.24.2021 - Insivumeh photos

Pacaya - lava flow of 02.24.2021 - Insivumeh photos

The seismic swarm continues in the Reykjanes Peninsula.

On February 24, two earthquakes above M5.0 were detected. One at 10:05 am from M5.7 and M5.0 at 10:30 am. At 12:37 a.m., an M4.8 earthquake was detected near Kleifarvatn. IMO's SIL system detected 11 earthquakes on M4.0 and much larger than M3.0. The earthquakes were felt throughout the SV part of Iceland, north of Húnaþing and west of Ísafjörður. Please note that the seismic activity is located on the Reykjanes Peninsula. Other major earthquake locations are unreliable.

Yesterday at 14:35, an earthquake of M3.5 was detected near Fagradalsfjall and another at 14:21 of M3.2. The earthquakes were felt in Reykjanes and the capital region. The swarm is still ongoing and since February 24, the SIL system has detected more than 4,200 earthquakes in the region.

 

Source: IMO

Reykjanes Peninsula - location and magnitude of earthquakes on 02.25.2021 at 3.15 p.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes on 02.25.2021 at 3.15 p.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes on 02.25.2021 at 3.15 p.m. - Doc. IMO

Reykjanes Peninsula - location and magnitude of earthquakes on 02.25.2021 at 3.15 p.m. - Doc. IMO

Reykjanes Peninsula - location and magnitude of earthquakes on 02/26/2021 at 7:00 a.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes on 02/26/2021 at 7:00 a.m. - Doc. IMO

Reykjanes Peninsula - location and magnitude of earthquakes on 02/26/2021 at 7:00 a.m. - Doc. IMO

InSAR image of the strong current earthquake sequence near Reykjavík. About 30 km of the boundary of the ENE trending plate has moved laterally to the left at depth with several right lateral strike-slip surface failures Coseismic N-S, including that of the magnitude 5.7 earthquake - Doc. Sigurjón Jónsson - Processed by Adriano Nobile, CDI group, KAUST

InSAR image of the strong current earthquake sequence near Reykjavík. About 30 km of the boundary of the ENE trending plate has moved laterally to the left at depth with several right lateral strike-slip surface failures Coseismic N-S, including that of the magnitude 5.7 earthquake - Doc. Sigurjón Jónsson - Processed by Adriano Nobile, CDI group, KAUST

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
 Pacaya - imageSentinel-2 bands 12,11,8A from 01.29.2021 via Mounts project

Pacaya - imageSentinel-2 bands 12,11,8A from 01.29.2021 via Mounts project

Pacaya - Thermal anomalies at the summit and on the lava flow - image Sentinel-2 bands12,11,5 du 29.01.2021 - Insivumeh

Pacaya - Thermal anomalies at the summit and on the lava flow - image Sentinel-2 bands12,11,5 du 29.01.2021 - Insivumeh

Pacaya - thermal anomalies at 01.02.2021 / 04:25 - Doc. Mirova_MODIS_logVRP

Pacaya - thermal anomalies at 01.02.2021 / 04:25 - Doc. Mirova_MODIS_logVRP

In the Pacaya, explosions, of varying level, follow one another and generate plumes of ash at 100-150 m. above the crater, dispersing westward for about 10 kilometers.

The flow on the southern flank measures on January 31 a length of 900 meters. Avalanches from the lava front reach 1,200 meters.

The tremor continues to be recorded, in connection with the ascent of magma, the movements of the lava flow and the pressure of the gases.

 

Source: Insivumeh

Reykjanes Peninsula - Grindavík with Mount Þorbjörn in the background - photo mbl.is / Kristinn Magnússon

Reykjanes Peninsula - Grindavík with Mount Þorbjörn in the background - photo mbl.is / Kristinn Magnússon

Some parts of Iceland shake more than others, and last year a total of 22,000 tremors were recorded on the Reykjanes Peninsula in southwest Iceland. Most of them had a magnitude less than 3.

Most activity has been concentrated in the area from the southwestern tip of Reykjanes to Lake Kleifarvatn in the east, but in recent months the activity and source of the tremors has shifted more to the east, towards Krýsuvík. On October 20 of last year, the source of a magnitude 5.6 earthquake was not far from Lake Djúpavatn.

The Reykjanes Ridge tectonic plate boundary stretches from west to east across the Reykjanes Peninsula. This is where the North American tectonic plate meets the Eurasian one.

On average, the plates are moving away from each other by about one cm per year, but in recent semesters movement in some areas of Reykjanes has reached 16 cm.

Kristín Jónsdóttir, earthquake hazards coordinator at the Icelandic Met Office, assumes that the pressure that builds up in the earth, between Lake Kleifarvatn and the Bláfjöll mountains, can only be released during a large earthquake. Two of them, magnitude 6.3 and 6, occurred in 1929 and 1968. Their source was near the Brennisteinsfjöll mountains, east of Lake Kleifarvatn.

Björn Oddsson, a geophysicist and program director in the Department of Civil Protection and Emergency Management, says the Reykjanes Peninsula is under constant surveillance. An uncertainty phase (the lowest alert phase) will remain there while the seismic activity is above average.

 

Source: Iceland Monitor

Reykjanes Peninsula - gauge between the North American and Eurasian tectonic plates - photo archives © Bernard Duyck

Reykjanes Peninsula - gauge between the North American and Eurasian tectonic plates - photo archives © Bernard Duyck

La Palma - the volcanic chain Cumbre Vieja - Fotoaereasdecanarias

La Palma - the volcanic chain Cumbre Vieja - Fotoaereasdecanarias

Since 04:11 (Canary Island time) on January 31, 2021, the Canary Islands seismic network operated by the Canary Islands Volcanological Institute (INVOLCAN) has been recording a new swarm of small-magnitude seismic events under the volcano Cumbre Vieja / La Palma

Among the many seismic events detected, 38 of them were located by the seismic network of the Canary Islands on La Palma until 11:02 am (Canary Island time) on January 31, 2021. The hypocenters fall under the western slope of the Cumbre Vieja volcano at depths between 15 and 20 km. The maximum magnitude observed was 1.8.

This new seismic swarm poses no danger to residents and visitors to La Palma given the low magnitude and depth of the earthquakes.

In the short and medium term, no significant change in volcanic activity is expected in Cumbre Vieja, which since 2017 has experienced 8 seismic swarms, including the one that started on January 31, 2021 (1 in 2017, 1 in 2018, 5 in 2020 and 1 in 2021).

In recent years, no significant horizontal and vertical displacement has been recorded via the Canary Islands GPS network in La Palma

Regarding the geochemical program for monitoring the volcanic activity of Cumbre Vieja, it is worth highlighting the observation of significant changes in the diffuse emission of hydrogen into the atmosphere by the Cumbre Vieja volcano linked to recent seismic swarms, as well as 'an increasing trend in the diffuse flux of carbon dioxide at the LP04 geochemical station.

 

Source: InVolcan

La Palma - seismic swarm at 31.01.2021 - Doc. InVolcano

La Palma - seismic swarm at 31.01.2021 - Doc. InVolcano

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Kilauea - drop in level of lava lake in Halema'uma'u on 12/26/2020 -a vent remains active, under a rainbow - USGS photo

Kilauea - drop in level of lava lake in Halema'uma'u on 12/26/2020 -a vent remains active, under a rainbow - USGS photo

In Kilauea, lava activity remains confined to Halemaʻumaʻu from two vents on the north and northwest sides of the crater.

At 2 p.m. yesterday, the crater lake was still 176m deep and the lake level appeared to be 2m. lower, leaving a narrow black rim around the northern edge. Early this morning, the west vent re-activated as the north vent calmed down and began to drain the lake. Reduced SO2 emissions were measured last night.

The north vent continued to erupt lava into a lake inside Halema'uma'u Crater. The west vent was glowing until about 2:40 a.m. this morning (almost coinciding with the change from a deflationary tilt to an inflationary summit tilt) when it became vigorously active with up to 3 narrow lava streams in the lake. After 3 a.m., the north vent calmed down and began to slowly drain lava from the lake, and the volume of the lava lake remained around 21 million cubic meters.

USGS field crews are currently taking measurements to confirm whether the lake's surface continues to decline.

Kilauea, Halema'uma'u - drop in lake level, marked by the rim, drained into the north vent - photo USGS

Kilauea, Halema'uma'u - drop in lake level, marked by the rim, drained into the north vent - photo USGS

A colder, solidified lava island floating in the lava lake, which slowly drifted northeast into the lake, apparently anchored near the northern vent. It is still around 260m in length and 115m in width (based on the heat map of December 23).

Kileauea - Halema'uma'u - lava rim around the lake and island anchorage near the north vent - cam. therm 12/26/2020 / USGS

Kileauea - Halema'uma'u - lava rim around the lake and island anchorage near the north vent - cam. therm 12/26/2020 / USGS

Kileauea - Halema'uma'u - thermal anomalies at 12/27/2020 / 12:25 am - Doc.Mirova_MODIS_Latest10NTI

Kileauea - Halema'uma'u - thermal anomalies at 12/27/2020 / 12:25 am - Doc.Mirova_MODIS_Latest10NTI

Preliminary analysis of sulfur dioxide emission rates measured last night suggests the rates have dropped to 16,000-20,000 tonnes / day. Summit tiltmeters continued to register a slowdown in deflationary tilt until 3 a.m. this morning (December 26) when they switched to inflationary tilt. Seismicity remained high but stable, with a few minor earthquakes and fluctuations in tremor related to the vigor of the fissure fountain.

 

Source: HVO-USGS

La Palma - Seismic swarm of 23-24.12.2020 under the Cumbre Vieja - Doc. I.G.N.

La Palma - Seismic swarm of 23-24.12.2020 under the Cumbre Vieja - Doc. I.G.N.

In recent years, several swarms or seismic series have been recorded on the Cumbre Vieja volcano in La Palma / Canary Islands.

The first occurred in October 2017. Then another was recorded in February 2018 and in 2020, has already given us 4 seismic swarms, according to IGN.

The new swarm occurred between 9:26 p.m. on December 23 and 9:29 p.m. on December 24.

At 2 p.m. on December 26, the IGN updated the information, claiming to have detected 602 seismic movements of which it had been able to locate 126. Also for them, the hypocentres of the events would be at a depth of about 30 km and the maximum recorded magnitude would be 2.3 mbLg. As for the energy released at the start of this seismic series, it would reach a value of 6x10 9 Joules.

La Cumbre Vieja / La Palma - Doc. FotoaerasdeCanarias

La Cumbre Vieja / La Palma - Doc. FotoaerasdeCanarias

Two institutions -IGN and INVOLCAN- are developing active monitoring of these processes because, although these are small-scale events and several kilometers deep, and last year more frequently, it seems likely that overpressure occurs as a result of movements of magmatic matter; we could therefore be faced with the first signs of a long term volcanic process.

 

Source: IGN & InVolcan

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Sinabung - pyroclastic flow on 30.10.2020 - photo Sadrah Peranginangin

Sinabung - pyroclastic flow on 30.10.2020 - photo Sadrah Peranginangin

In Sinabung, the PVMBG reported for October 30 two pyroclastic flows moving over 2,000 to 2,500 meters and avalanches over 500 to 1,000 meters, in a southeast and south direction. A plume is observed at 50-500 above the crater.

The seismicity of October 30 is broken down into:

- 2 earthquakes accompany the pyroclastic flows

- 77 earthquakes of collapse

- 11 blast earthquakes

- 16 low frequency earthquakes

- 9 hybrid / multiphase earthquakes

- 2 distant tectonic earthquakes.

The activity level remains at 3 / siaga.

 

Source: PVMBG and Beidar sinabung

Sinabung - pyroclastic flow of 30.10.2020 / 12:03 p.m. WIB - photo Sadrah Peranginangin

Sinabung - pyroclastic flow of 30.10.2020 / 12:03 p.m. WIB - photo Sadrah Peranginangin

 Sinabung - 10/30/2020 / 2:10 p.m. WIB - photo Sadrah Peranginangin

Sinabung - 10/30/2020 / 2:10 p.m. WIB - photo Sadrah Peranginangin

The explosions follow one another on Suwanosejima, in the Ryukyu archipelago.

The JMA noted 2 episodes on October 31 at 2:15 p.m. and 3:40 p.m. local time, respectively accompanied by an ash plume at a height of 800 m. and 1,000 m. above the crater.

VAAC Tokyo issued 11 volcanic ash advisories between October 29 and October 31 (6:49 am UTC)

 

Sources: JMA & VAAC Tokyo.

Suwanosejima - 10/31/2020 / 2:11 p.m.- 2:18 p.m. - JMA webcam

Suwanosejima - 10/31/2020 / 2:11 p.m.- 2:18 p.m. - JMA webcam

 Suwanosejima - 10/31/2020 / 3:41 p.m.-3:42 p.m. - JMA webcam

Suwanosejima - 10/31/2020 / 3:41 p.m.-3:42 p.m. - JMA webcam

On October 30, 2020 at 10:30 p.m., the Phivolcs issued an advisory concerning the generation of post-eruptive lahars for the volcanoes of Luzon - Mayon, Pinatubo and Taal -, following the prolonged heavy rains, caused by Typhoon Rolly.

 

Sources: Phivolcs

Lahar at Mayon - photo archives Romeo Ranoco / Reuters 2018

Lahar at Mayon - photo archives Romeo Ranoco / Reuters 2018

After the M6.6 - 7 earthquake that hit the Aegean Sea, the Turkish coast and the Greek island of Samos, followed by numerous aftershocks, the authorities recommended that residents meet in open spaces and set up for the victims tents and camp beds.

In addition to the material damage, two teenagers were killed on Samos when a wall fell.

The total provisional toll has grown: at least 26 dead and 800 injured.

 

Source: European media.

Samos - damage following the earthquake of 30.10.2020 - via Facebook

Samos - damage following the earthquake of 30.10.2020 - via Facebook

Izmir region in Turkey - Damage following the earthquake of 30.10.2020 - EMSC photos - one click to enlarge Izmir region in Turkey - Damage following the earthquake of 30.10.2020 - EMSC photos - one click to enlarge

Izmir region in Turkey - Damage following the earthquake of 30.10.2020 - EMSC photos - one click to enlarge

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Publié le par Bernard Duyck
Publié dans : #Sismologia
A building collapsed following the earthquake of the day in Turkey. - EMSC photo

A building collapsed following the earthquake of the day in Turkey. - EMSC photo

High magnitude and shallow depth earthquake in the Aegean Sea - 10.30.2020 / 11:51 UTC - EMSC maps
High magnitude and shallow depth earthquake in the Aegean Sea - 10.30.2020 / 11:51 UTC - EMSC maps

High magnitude and shallow depth earthquake in the Aegean Sea - 10.30.2020 / 11:51 UTC - EMSC maps

The M 7.0 earthquake (revised to 6.6 by the University of Athens) of October 30, 2020 off the island of Samos, Greece, occurred following a normal fault at shallow depth of the earth's crust in the Eurasian tectonic plate in the eastern Aegean Sea.

The location of the October 30, 2020 event is approximately 250 km north of the nearest main plate boundary, where the Africa plate is moving north at a speed of approximately 10 mm / year relative to to Eurasia; this earthquake is therefore considered an intraplate event.

High magnitude and shallow earthquake in the Aegean Sea - 10.30.2020 / 11:51 UTC - Univ. from Athens, seismology lab / via Evi Nomikou

High magnitude and shallow earthquake in the Aegean Sea - 10.30.2020 / 11:51 UTC - Univ. from Athens, seismology lab / via Evi Nomikou

The focal mechanism solution indicates that the earthquake occurred on a moderately pendulous normal fault striking either east or west. This mechanism indicates a north-south oriented extension that is common in the Aegean Sea.

The tectonics in the region surrounding this earthquake are relatively complex; to the south, the lithosphere of Africa (Nubia) subducts to the north under the Eurasian plate to the Hellenic trench; in the east, the Anatolian microplate (part of Eurasia) moves in a general direction towards the west, causing a right lateral fault along its northern boundary, the North Anatolian fault and a left lateral fault in the south -est of Turkey. The Aegean region, western Turkey and southern Greece, where the October 30 earthquake occurred, is generally experiencing a north-south extension driven by southward migration of the pit. Hellenic. (USGS earthquake hazards program)

 

A “mini-tsunami” occurred on the Greek island of Samos in the Aegean Sea and material damage to buildings was recorded following a strong 6.7 earthquake which hit this sea island Aegean, according to Greek public television, Ert.

According to Turkish authorities, the disaster left at least 4 dead and 120 injured.

 

Sources: USGS earthquake hazards program, EMSC, and European media.

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
 Villarica - small explosion from 23.10.2020 / 10:41 local - photo Sernageomin

Villarica - small explosion from 23.10.2020 / 10:41 local - photo Sernageomin

An LP earthquake was recorded on October 23 at 10:41 am local time in Villarica, associated with a moderate explosion at the active crater, accompanied by a plume of ash 180 meters high in incline towards me .; the displacement reduced (DR) to 4.1 cm².

The technical alert remains at amarilla.

The POVI has established the schedule of pyroclast emissions over the last 2 months: in September 2020: 3 - in October 2020: 6.

Villarica - summary in photos (07.08.2020 / 20.10.2020) and schedule of pyroclast emissions over the last 2 months - Doc. POVI via Werner Keller
Villarica - summary in photos (07.08.2020 / 20.10.2020) and schedule of pyroclast emissions over the last 2 months - Doc. POVI via Werner Keller

Villarica - summary in photos (07.08.2020 / 20.10.2020) and schedule of pyroclast emissions over the last 2 months - Doc. POVI via Werner Keller

A drone flight over the Villarica crater by drone was carried out last week, revealing that recent explosions have deposited large lava splashes and boulders, some up to several meters. These projectiles are ejected, sometimes at supersonic speeds and reach parabolic trajectories. Its temperature is around 1000 ° C. Although the ascent is not forbidden, all those who undertake it must take into account these types of dangers, and the unpredictability of explosions, which lack instrumental precursors.

In addition, these explosions were caused by the conjunction between the level variations of the lava lake, which is a few hundred meters away in the conduit, and the falls of pyroclast crusts in the cylindrical conduit. 

 

Source: Sernageomin

Copahue - the plume seen from Caviahue 23.10.2020 - photo Valentina Sepulveda / Caviahue.

Copahue - the plume seen from Caviahue 23.10.2020 - photo Valentina Sepulveda / Caviahue.

In Copahue, on the Chilio-Argentina border, on October 23, we observe a plume of gas, lightly loaded with ash, blown by the winds above the village and Lake Caviahue.

According to Sernageomin, the seismic activity of the Copahue remains at a low level, but there are transient increases in the amplitude of the tremor, in relation to the emissions of particulate materials, suggesting the interaction between the magma and the superficial hydrothermal system. .

On the satellite images, we can observe a large area of ​​ash deposits estimated between 6-7 km. In diameter, mainly in the proximal area of ​​the crater.

 

Sources: Sernageomin and photo by Valentina Sepulveda / Twitter.

Etna - 23.10.2020 - activity of the "mouth of the Saddle" / NSEC - photo Gio Giusa

Etna - 23.10.2020 - activity of the "mouth of the Saddle" / NSEC - photo Gio Giusa

At Etna, an INGV press release dated 23.10.2020 / 8:32 UTC announces that the increase in explosive activity at the New Southeast Crater (NSEC), reported in the previous press release (Etna Communiqué 'Update n. 87 at 06:41 UTC), is no longer observable, as is the associated ash cloud.

However, strombolian activity of varying intensity remains at the NSEC, which fuels sporadic and light ash emissions that are rapidly dispersed in the summit area. Sporadic and light ash emissions can also be observed from the Bocca Nuova (BN) crater.

The temporal trend of the mean amplitude of the volcanic tremor and the location of its source, like infrasound activity, did not show significant changes. Signals from soil deformation monitoring stations do not show significant changes.

 

Source: INGV OE

Reykjanes Peninsula - location and magnitude of earthquakes as of 23.10.2020 / 2 p.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes as of 23.10.2020 / 2 p.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes as of 23.10.2020 / 2 p.m. - Doc. IMO

Reykjanes Peninsula - location and magnitude of earthquakes as of 23.10.2020 / 2 p.m. - Doc. IMO

IMO provided an update on October 23 on the seismic swarm of the Reykjanes Peninsula : On October 20 at 13:43, an earthquake of M5.6 occurred west of Kleifarvatn, at a depth of 10 km.

Almost 3,000 aftershocks were detected in the current swarm, the majority of them within two days of the M5.6 earthquake. About 30 aftershocks measured larger than M3.0. As of October 23, around 80 earthquakes were detected in the region, the largest of M2.6 near Kleifarvatn.

It is complicated to assess whether the swarm is decreasing or whether the activity has temporarily decreased. It is therefore not excluded that the seismic activity of the Reykjanes peninsula will increase again.

Reykjanes Peninsula - fisure in Krýsuvíkurbjarg on 10/21/2020, after the major earthquake of October 20 - photo Coast Guard Sævar Óskarsson / Visir.is

Reykjanes Peninsula - fisure in Krýsuvíkurbjarg on 10/21/2020, after the major earthquake of October 20 - photo Coast Guard Sævar Óskarsson / Visir.is

The meteorological office said on Wednesday there were indications that cracks in Krýsuvíkurbjarg had crept in and new ones were forming.

Ármann Höskuldsson, a geologist at the University of Iceland, says it is highly undesirable for people to travel on steep slopes or cliffs like in Krýsuvík during this earthquake cycle.

Reykjanes Peninsula - 10.2020 - The InSAR Sentinel-1 image of the co-seismic deformation shows the expected north-south right lateral setback failure (processed by Y. Cao, CDI Group, KAUST)

Reykjanes Peninsula - 10.2020 - The InSAR Sentinel-1 image of the co-seismic deformation shows the expected north-south right lateral setback failure (processed by Y. Cao, CDI Group, KAUST)

The InSAR Sentinel-1 image of the co-seismic deformation shows the expected north-south right lateral setback failure (processed by Y. Cao, CDI Group, KAUST). - via Sigurjón (Sjonni) Jónsson - Professor of Geophysics, KAUST

 

A full explanation of the seismic and intrusive phenomena that the Reykjanes Peninsula has experienced since early 2020 is given by Páll Einarsson, of the Institute of Earth Sciences, University of Iceland.

 

Sources: IMO, KAUST, Univ. Of Iceland

Earthquakes in the Reykjanes Peninsula - video in English (mixed with Icelandic accent, requiring focus) by Páll Einarsson / Univ of Iceland / Landhelgisgæsla Íslands

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 Bezymianny - 21.10.2020 / 20h29 - Doc. KB GS RAS via Olga Girina

 Bezymianny - 21.10.2020 / 20h29 - Doc. KB GS RAS via Olga Girina

An explosive eruption of the Bezymyanny volcano occurred on October 21, 2020 at 20:22 UTC. The ash cloud is located above the Klyuchevskaya group of volcanoes. First reported at an altitude of 8,500 meters, the height of the ash cloud rose to 5,500 meters later.

The VAAC Tokyo has issued an ash dispersion advisory 4 times, as they cross various air routes during their dispersion.

A red aviation code was issued, before changing to orange.

Sources: VAAC Tokyo, KVERT & Olga Girina

Bezymianny - Thermal anomalies at 10/22/2020 / 02:25 am - Doc. Mirova MODIS
Bezymianny - Thermal anomalies at 10/22/2020 / 02:25 am - Doc. Mirova MODIS

Bezymianny - Thermal anomalies at 10/22/2020 / 02:25 am - Doc. Mirova MODIS

October 21, 2020, ~ Eruption ~ Bezymianny Volcano, Russia / Volcano Time lapse

Two other volcanoes are active in the Kamchatka Peninsula: Klyuchevskoy and Karymsky.

 

At Klyuchevskoy, the explosive-effusive eruption continues at a moderate level.

The almost continuous explosions produce plumes of gas and steam, containing a little ash, at an altitude of about 5,200 meters, drifting north-east.

The lava flow in Apakhonchich falls remains active.

The thermal anomalies noted by Mirova were of max. VRP 778 MW on October 20, 457MW on October 21, and Between VRP 652 and 425 MW on October 22, 2020.

Klyuchevskoy - Thermal anomalies at 22.10.2020 / 02:25 - Doc. Mirova Modis
Klyuchevskoy - Thermal anomalies at 22.10.2020 / 02:25 - Doc. Mirova Modis

Klyuchevskoy - Thermal anomalies at 22.10.2020 / 02:25 - Doc. Mirova Modis

At the Karymsky, according to data from pilots, explosions sent ash up to 4,000 m. altitude, around 02:30 UTC on October 21. The ash plume continues to drift south-east of the volcano for 40 km. The last Karymsky explosions were noted on July 29, 2020.

Moderate eruptive activity of the volcano continues. Ash explosions up to 19,700-23,000 feet (6-7 km) above sea level could occur at any time. Ongoing activities could affect low-flying planes.

The aviation code has changed to orange.

 

Sources: KVERT & VAAC Tokyo

Karymsky - photo A.Belousov via Volkstat / 21.10.2020

Karymsky - photo A.Belousov via Volkstat / 21.10.2020

Karymsky- volcanic ash advisory on 21.10.2020 / 0600Z  - Doc. VAAC Tokyo

Karymsky- volcanic ash advisory on 21.10.2020 / 0600Z - Doc. VAAC Tokyo

On October 20 at 13:43, an earthquake of M5.6 occurred in Núplahlíðarháls on the Reykjanes peninsula.

More than 2,000 aftershocks have been detected in the ongoing swarm. About 30 aftershocks measured more than M3.0 and some were felt in the Reykjanes Peninsula, the capital region and Borgarfjördur.

Travelers and hikers are advised to use caution near the steep slopes in Reykjanes due to the increased likelihood of rockfall as the seismic swarm continues.

Source: IMO

Reykjanes peninsula - seismic swarm at 10/22/2020 / 07:15 am - Doc. IMO
Reykjanes peninsula - seismic swarm at 10/22/2020 / 07:15 am - Doc. IMO

Reykjanes peninsula - seismic swarm at 10/22/2020 / 07:15 am - Doc. IMO

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
 Karymsky - photo D. Melnikov. IVS FEB RAS, KVERT 13.10.2020

 Karymsky - photo D. Melnikov. IVS FEB RAS, KVERT 13.10.2020

Karymsky - Volcanic ash advisory - Doc Vaac Tokyo 21.10.2020 - 0600Z

Karymsky - Volcanic ash advisory - Doc Vaac Tokyo 21.10.2020 - 0600Z

According to data from AMC Elizovo (pilots), explosions from the Karymsky sent ash up to 4,000 m. altitude, around 02:30 UTC on October 21. The ash plume continues to drift south-east of the volcano for 40 km. The last Karymsky explosions were noted on July 29, 2020.

Moderate eruptive activity of the volcano continues. Ash explosions up to 19,700-23,000 feet (6-7 km) above sea level could occur at any time. Ongoing activities could affect low-flying planes.

The aviation code has changed to orange.

 

Sources: KVERT & VAAC Tokyo

 Merapi - photo BPPTKG 10/21/2020 / 6:29 a.m.

Merapi - photo BPPTKG 10/21/2020 / 6:29 a.m.

Merapi - summary of the seismic activity of 20.10.2020 / 00-24h WIB - Doc. BPPTKG

Merapi - summary of the seismic activity of 20.10.2020 / 00-24h WIB - Doc. BPPTKG

Thanks to the seismographic recordings of October 20, 2020, it was recorded at Merapi, where the activity seems more intense:

- 28 earthquake collapse

- 37 blast earthquakes

- 27 low frequency earthquake

- 83 hybrid / multiphase earthquakes

- 18 shallow volcanic earthquakes

- 2 distant tectonic earthquakes.

The current potential danger is in the form of pyeoclastic flows associated with the collapse of the lava dome and the fall of volcanic material due to explosive eruptions.

Activity level remains at 2 / waspada, with a 3 km no-go zone from the summit.

 

Sources: PVMBG & BPPTKG

Villarica - photo Sernageomin 20.10.2020 17:22 loc.

Villarica - photo Sernageomin 20.10.2020 17:22 loc.

On October 20 at 5:22 p.m. local time, an LP earthquake occurred in Villarica, associated with a moderate explosion at the active crater, accompanied by an ash plume reaching 240 meters above the emission bridge.

No significant changes in seismicity, the volcanic technical alert remains at amarilla.

 

Source: Sernageomin

 Reykjanes Peninsula - earthquakes at 20.10.2020 / 15:40 - Doc .IMO

Reykjanes Peninsula - earthquakes at 20.10.2020 / 15:40 - Doc .IMO

Reykjanes Peninsula - earthquakes at 21.10.2020 / 06:30 - Doc .IMO
Reykjanes Peninsula - earthquakes at 21.10.2020 / 06:30 - Doc .IMO
Reykjanes Peninsula - earthquakes at 21.10.2020 / 06:30 - Doc .IMO

Reykjanes Peninsula - earthquakes at 21.10.2020 / 06:30 - Doc .IMO

At 1:43 p.m. on October 20, an M5.6 earthquake occurred in Núpshlíðarháls, about 5 km west of the Seltún geothermal area on the Reykjanes peninsula.

The earthquake was felt widely across the country, particularly in the southern part of the Reykjanes peninsula and in the capital region, about 25 km from the epicenter.The earthquake was felt also in the Westman Islands and Borgarnes.

To date, more than 250 aftershocks have been detected, the most important of the period between 3:27 pm and 3:32 pm The most important was M4.1, the other earthquakes between 3.0 and 3.8 . There is no sign of volcanic unrest in the area.

Krýsuvík - small slow landslide on 20.10.2020 - photo Arni Saeberg / mbl.is

Krýsuvík - small slow landslide on 20.10.2020 - photo Arni Saeberg / mbl.is

Today's earthquake is the largest measured earthquake in the Reykjanes Peninsula since 2003.

"There is a long term active process underway in the region and we can expect that there will be more earthquakes in the coming hours that will make themselves felt all the way to the capital region. ", says Kristín Jónsdóttir, seismic risk coordinator at the Islandic Met Office, in an interview with RÚV today.

GPS measurements indicate that a slow landslide is taking place near Krýsuvík, according to Kristín Jónsdóttir. When asked about the next steps, she says an announcement has been received of an unusually strong smell of gas and Kristín believes that today's large earthquake "only took root in the geothermal system."

 

Sources: IMO, RUV, EMSC

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Etna - activity of the new south-eastern crater on 08/29/2020 - photo Gio Giusa

Etna - activity of the new south-eastern crater on 08/29/2020 - photo Gio Giusa

The National Institute of Geophysics and Volcanology, Etneo Observatory, announces that the activity of the new SE crater of Etna is characterized, from the morning of August 28, by a discontinuous and modest ash emission which produces a strongly volcanic cloud. diluted, light gray in color.

The volcanic cloud, which reaches a height of about 4.5 km above sea level, is quickly dispersed eastward by high-altitude winds.

Concerning the temporal trend of the mean amplitude of the volcanic tremor: it continues to show marked amplitude fluctuations with respect to the whole, defining a substantially stationary trend which is mainly maintained in the range of mean values. The location of the source of the quake is located near the SE crater / new south-eastern crater, at a depth of about 2900-3000 meters above mean sea level.

From an infrasonic activity perspective, over the past 24 hours, events have mainly resulted from areas at the New Southeast Crater and the Northeast Crater.

Analysis of the data from the permanent and clinometric GNSS networks shows no significant soil deformation.

 

From 11:30 UTC, the ash emission gradually intensified at New SE Crater, which produced an eruptive cloud that reached a height of about 4.5 km above sea level towards the EAST / BORN.

There are currently no reports of ash fall in the inhabited centers of the Etnean region.

Concerning the temporal trend of the mean amplitude of the volcanic tremor, it continues to show marked amplitude fluctuations compared to the whole.
 

Etna - ash plume from the new south-eastern crater on 08/29/2020 - photo Gio Giusa

Etna - ash plume from the new south-eastern crater on 08/29/2020 - photo Gio Giusa

Etna - amplitude of the tremor on 08/30/2020 - Doc INGV OE

Etna - amplitude of the tremor on 08/30/2020 - Doc INGV OE

The National Institute of Geophysics and Volcanology, Etneo Observatory, informs that around 14:55 UTC on August 29, the emission of ash at the new south-eastern crater has ceased.

There remains an intense degassing, sometimes accompanied by a discontinuous and light explosive activity.

 

Sources: INGV OE & Gio Giusa

Reykjanes Peninsula - location and magnitude of earthquakes as of 08/30/2020 / 6:55 am - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes as of 08/30/2020 / 6:55 am - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes as of 08/30/2020 / 6:55 am - Doc. IMO

Reykjanes Peninsula - location and magnitude of earthquakes as of 08/30/2020 / 6:55 am - Doc. IMO

At 7:06 p.m. and 7:08 p.m. on August 29, earthquakes M3.6 and M3.0 occurred just west of Kleifarvatn on the Reykjanes peninsula. Two earthquakes of similar magnitude, M3.4 and M3.0 occurred in the same location at 4:23 pm and 4:39 pm yesterday. The earthquakes were felt in the Reykjanes Peninsula, the capital region and Akranes. Smaller aftershocks have since occurred and are expected to continue.

The seismic activity is likely caused by stress changes in the crust due to multiple magma intrusions on the Reykjanes Peninsula since January this year.

 

Source: IMO

Yellowstone N.P. - Giantess Geyser - photo J.R. Douglass / NPS archives

Yellowstone N.P. - Giantess Geyser - photo J.R. Douglass / NPS archives

In Yellowstone, the Giantess Geyser, located in the Upper Geyser Basin, came into operation on August 25, after an eruption-free period of over 6.5 years.

See the video on: https://twitter.com/i/status/1299708384015458307

 

Source: Yellowstone NPS

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia

In Fuego, Guatemala, the explosions follow one another at a rate of 4 to 6 per hour, accompanied by shock waves, avalanches of blocks in the direction of the Seca, Taniluya, Ceniza, Trinidad and Las Lajas drainages, some of which reach the limit of vegetation, and ash plumes at 4,500-4,700 meters above sea level.

Ash falls are reported in the villages of Panimaché I, Morelia, Finca Palo Verde and Yepocapa.

Incandescent pulses are observed during the night and early in the morning.

 

Source: Insivumeh

Fuego - explosion of 08/26/2020 / 2h31 - Doc. IDIS / Epcom / CRELOSA

VAAC Darwin reports discreet eruptive activity over Kadovar, Papua New Guinea; the ash can reach flight altitude 70, while the plume of sulfur dioxide moves far to the northwest.

 

Sources: VAAC Darwin and Sentinel-2

Kadovar - image Sentinel-2 L1C bands 12,11,4 from 08/22/2020 - one click to enlarge

Kadovar - image Sentinel-2 L1C bands 12,11,4 from 08/22/2020 - one click to enlarge

On August 26, 2020 at 4:15 PM, an M4.2 earthquake occurred about 10 km NE of Grindavík. Another M3.7 earthquake occurred in a similar location at 1:43 p.m. IMO has received many felt reports from the southwestern part of Iceland regarding these earthquakes.

At 5:06 am on August 27, an M2.9 earthquake was detected near Fagradalsfjall but a swarm of earthquakes is still in progress there.

In total, the IMO reports five earthquakes of magnitude equal to or greater than 3 over the last two days.

 

An intense seismic swarm began on July 19 in the Reykjanes Peninsula. More than 5,000 earthquakes have been detected since then. This seismic activity is likely caused by a stress change in the crust due to multiple magma intrusions on the Reykjanes Peninsula since January of this year.

 

Source: IMO

Reykjanes Peninsula - location and magnitude of earthquakes as of 08/27/2020 / 6:40 a.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes as of 08/27/2020 / 6:40 a.m. - Doc. IMO
Reykjanes Peninsula - location and magnitude of earthquakes as of 08/27/2020 / 6:40 a.m. - Doc. IMO

Reykjanes Peninsula - location and magnitude of earthquakes as of 08/27/2020 / 6:40 a.m. - Doc. IMO

The fissured slope of the Irazú volcano, located on the western flank of the Carthaginian colossus, collapsed on the morning of August 26 at a rate that remains to be determined.

The event took place at around 4:10 a.m. when officials who were there began to perceive a seismic movement and vibration which, according to their reports, lasted for about a minute and a half.

Cyril Muller, an Ovsicori expert, told Costa Rica Noticias that just yesterday there were at least 100 small landslides; and that between Monday and Tuesday, the crack in the slope had moved 40 centimeters.

The displaced materials are estimated to be several million cubic meters of earth.

Alexander Solís, president of the National Emergency Commission (CNE) said in Repretel News that this event is a landslide and has nothing to do with volcanic activity.

The damage is material, and concerns telecommunications installations that could not be moved.

 

Sources : Ovsicori Videos and Media from Costa Rica

https://www.facebook.com/OVSICORI/videos/1410561832465897

https://www.facebook.com/OVSICORI/videos/868543520339934

Irazu - the area affected by the landslide, and movement between February and August towards the NW - Doc. Ovsicori

Irazu - the area affected by the landslide, and movement between February and August towards the NW - Doc. Ovsicori

Irazu - seismic traces of the landslide of 26.08.2020 - Doc.Ovsicori

Irazu - seismic traces of the landslide of 26.08.2020 - Doc.Ovsicori

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