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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
Suwanosejima - 17.08.2020 - image Sentinel-2 / EO browser / Copernicus

Suwanosejima - 17.08.2020 - image Sentinel-2 / EO browser / Copernicus

A small explosion occurred on August 17 in Suwanosejima, in the Ryulyu volcanic arc. According to reports, ash emissions reached up to 2,133 m above sea level.

An eruption was reported by the JMA on August 18, 2020 around 8 p.m. at Suwanosejima; it was accompanied by a plume of gas and ash which rose to 1,200 meters above the crater, then dissipated towards the south

Source: JMA & Copernicus / Sentinel-2

Suwanosejima - eruptive plume on 08/18/2020 / 8 p.m. - JMA webcams

Suwanosejima - eruptive plume on 08/18/2020 / 8 p.m. - JMA webcams

The main plume of the crater, white and gray, with a moderate to thick intensity, is observed this August 18 at about 2000 meters from the summit of Sinabung.

At the level of seismicity, we distinguish :

- 6 blast earthquakes, with an amplitude of 12 to 45 mm and a duration of 22 to 73 seconds.

- 32 low frequency earthquakes, with an amplitude of 2 to 15 mm, and the duration of the earthquake was 7 to 16 seconds.

- 4 local tectonic earthquakes, with an amplitude of 4-34 mm, S-P 1.6-3 seconds and a long earthquake of 11-29 seconds.

- 3 distant tectonic earthquakes, with an amplitude of 5-13 mm, S-P 28.4-31 seconds and a long earthquake of 86-696 seconds.

- 4 episodes of continuous tremor with an amplitude of 0.5 to 60 mm, dominating 10 mm.

 

The activity level is at 3 / siaga, with a red aviation code.

 

Sources: PVMBG, Magma Indonesia and VAAC Darwin.

Sinabung - 18.08.2020 - ash plume 2,000 meters above the summit - photo Sadrah Peranginangin

Sinabung - 18.08.2020 - ash plume 2,000 meters above the summit - photo Sadrah Peranginangin

Sinabung - time-lapse 18.08.2020 - Doc. PVMBG via Volcano YT

Two violent earthquakes off Bengkulu rocked the Indonesian island of Sumatra. The 6.8 and 6.9 magnitude earthquakes occurred at 5:23 a.m. local / 10:23 p.m. GMT and 5:29 a.m. local / 10:29 p.m. GMT on August 18, 2020, as reported by monitoring stations.

No tsunami warning has been issued, nor an assessment of the damage caused by these earthquakes.

They have to do with the subduction of the Indo-Australian plate under the Sunda plate.

 Strong earthquakes off Bengkulu / Sumatra - 08/18/2020 - Doc. Temblor

Strong earthquakes off Bengkulu / Sumatra - 08/18/2020 - Doc. Temblor

The Manna seismic station, south of Bengkulu, recorded 2 earthquakes of M greater than 6 on 08/18/2020.

The Manna seismic station, south of Bengkulu, recorded 2 earthquakes of M greater than 6 on 08/18/2020.

An earthquake of M 6.6 struck Masbate Island on August 18, 2020 at 8:30 a.m. local / 12:03 a.m. GMT in the Philippines. It was followed by strong aftershocks.

We deplore one death and dozens of wounded; much damage to homes is due to its shallow depth and power.

The origin is tectonic.

 

Sources: USGS Earthquake Hazards - EMSC - Local Observatory

 Philippines / Masbate region - damage to homes on 08/18/2020 - photo Philippine Red Cross Masbate

Philippines / Masbate region - damage to homes on 08/18/2020 - photo Philippine Red Cross Masbate

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Sinabung - eruptive episode and pyroclastic flows of 08/10/2020 / 10:16 a.m. - photo PVMBG & Magma Indonesia

Sinabung - eruptive episode and pyroclastic flows of 08/10/2020 / 10:16 a.m. - photo PVMBG & Magma Indonesia

The activity of Gunung Sinabung seems to have regained its past eruptive mode, with this August 10, 2020 at 10:16 WIB a plume of ash and gas with a height of ± 5000 m above the summit (± 7460 m above the level from the sea).

A new eruptive episode occurred at 11:17 local time.

 

In terms of seismicity, we notice an increase in the number of deep volcanic earthquakes:

- on August 9, 39 deep volcanic earthquakes, with an amplitude of 2 to 70 mm, S-P 1.1 to 4 seconds and an earthquake duration of 9 to 23 seconds.

- This August 10, between 00h and 12h, 47 deep volcanic earthquakes - with an amplitude of 2 to 30 mm, SP 1.5 to 4 seconds and duration of the earthquakes from 9 to 21 seconds between 00 and 6 a.m., then with an amplitude of 2-120 mm, SP 1.4-4 seconds and the duration of the earthquakes of 9-23 seconds, between 6 and 12h.

Between 6 a.m. and 12 p.m., there are 2 eruption earthquakes, with an amplitude of 120 mm, and a duration of 1785-2246 seconds.

 

Currently, Mount Sinabung is at level III / Siaga

 

Source: Dr. Devy Kamil Syahbana and Magma Indonesia

 Sinabung - episode of 08/10/2020 / 11:32 WIB - photo PVMBG & Magma Indonesia

Sinabung - episode of 08/10/2020 / 11:32 WIB - photo PVMBG & Magma Indonesia

Sinabung - seismicity as of 09.08.2020 - increase in deep volcanic earthquakes - Doc. Magma Indonesia

Sinabung - seismicity as of 09.08.2020 - increase in deep volcanic earthquakes - Doc. Magma Indonesia

Etna presented at the NSEC's "saddle cone" an increased Strombolian activity on the night of August 9, followed by ash emissions with an impressive plume seen from Torre del Filosofo at 3,000 meters.

 

Sources: Boris Behncke, Salvatore lo Giudice and Gio Giusa

 Etna - Strombolian activity at the SEC saddle cone, reflected on the clouds on 07.08.2020 - photo Boris Behncke

Etna - Strombolian activity at the SEC saddle cone, reflected on the clouds on 07.08.2020 - photo Boris Behncke

Etna - ash emission on 09.08.2020, view from Torre del Filosofo - photo Gio Giusa

Etna - ash emission on 09.08.2020, view from Torre del Filosofo - photo Gio Giusa

Regarding the monitoring of the activity of the Nevado del Ruiz volcano, the Servicio Geologico Columbiano, informs that from August 8, 2020 at 00:50 (local time), there was a significant increase in the volcano- seismic activity. tectonic, associated with the fracturing of rocks around the volcanic building.

The seismic activity is located in the West-South-West sector at an average distance of 6.0 km from the Arenas crater. The recording of a volcano-tectonic earthquake that occurred at 7:04 a.m. (local time), at a depth of 4.1 km with a magnitude of 3.1 ML (local magnitude), is reported as felt by officials of the National Natural Park of Los Nevados.

The Nevado del Ruiz volcano continues at activity level 3 amarilla / changes in the behavior of volcanic activity.

 

Source: SGC

Nevado del Ruiz - photo SGC

Nevado del Ruiz - photo SGC

In Iceland, the seismic swarm in the Eyjafjördur / Tjörnes FZ area seems to be resuming on August 9, with 3 earthquakes of magnitude between 3.5 and 4.5. earthquakes of magnitude 3 or less have continued since.

 

Source: IMO

Iceland - seismic swarm of Tjörnes FZ at 08.09.2020 / 4:35 p.m. - location and magnitude of earthquakes - Doc. IMO
Iceland - seismic swarm of Tjörnes FZ at 08.09.2020 / 4:35 p.m. - location and magnitude of earthquakes - Doc. IMO
Iceland - seismic swarm of Tjörnes FZ at 08.09.2020 / 4:35 p.m. - location and magnitude of earthquakes - Doc. IMO

Iceland - seismic swarm of Tjörnes FZ at 08.09.2020 / 4:35 p.m. - location and magnitude of earthquakes - Doc. IMO

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Activity of Sabancaya, Ubinas and earthquake south of Big Island

The Geophysical Institute of Peru (IGP) reports that the eruptive activity of the Sabancaya volcano remained between July 20 and July 26 at moderate levels, with the continuous recording of explosions, on average 13 per day, with plumes of gas and ash up to 2.6 km above the top of the volcano.

The IGP recorded and analyzed the occurrence of about 400 earthquakes of volcanic origin, associated with the circulation of magmatic fluids (magma, gas, etc.) inside the volcano.

The monitoring of the deformation of the volcanic structure, using GNSS data (processed with fast orbits), did not show any significant anomalies; however, a slight inflation was recorded in the northern sector (Hualca Hualca volcano) and south-eastern flank of the Sabancaya volcano. Satellite monitoring has identified the presence of 5 thermal anomalies with values ​​between 1 MW and 4 MW VRP, associated with the presence of a lava body on the surface of the volcano crater.

The volcanic alert level remains orange, with a prohibited area of ​​12 km in radius around the crater.

 

Source: IG Peru

Activity of Sabancaya, Ubinas and earthquake south of Big Island

The Ubinas volcano (Moquegua region) continues to show a slight increase in its seismic activity between July 20 and July 26; twenty earthquakes of magnitudes less than M1.5, associated with rock breaking processes that occur inside the volcano have been recorded; similarly, 6 seismic signals were recorded which would be associated with the movements of volcanic fluids (water vapor and gas); Within these, 2 tornillo-type events were identified which would be linked to the increase in the internal pressure of the volcano. No seismic activity linked to the rise of magma is observed.

Surveillance cameras recorded columns of gas and water vapor reaching heights of up to 700 m above the summit of the volcano, dispersed towards the southeastern sector of the volcano.

The monitoring of the deformation of the volcanic structure, using GNSS instruments, as well as the satellite monitoring via the SENTINEL, IMO-NASA (SO2 gas) and MIROVA (thermal anomalies) systems did not record any anomalies. during the analysis period.

The volcanic alert level remains at Naranja, with a forbidden zone of 3 km in radius around the crater

 

Source: IG Peru

Activity of Sabancaya, Ubinas and earthquake south of Big Island

The US Geological Survey's Hawaiian Volcanoes Observatory (HVO) recorded a magnitude 4.7 earthquake between Lōʻihi seamont and the southern tip of the island of Hawaii on Monday, July 27 at 6:06 a.m. HST .

The earthquake was centered about 20 km (12.4 miles) southeast of Nā’ālehu, at a depth of 35 km (21.7 miles). Slight shaking, with a maximum intensity of IV, has been reported in parts of the island of Hawaii. At this intensity, significant damage to buildings or structures is not expected.

Acting HVO scientist David Phillips said the earthquake had no apparent effect on Kīlauea or Mauna Loa volcanoes. "We are not seeing any detectable change in activity at the summits or along the Mauna Loa or Kīlauea rift zones as a result of this earthquake. Aftershocks are possible and could be felt." The HVO continues to monitor Mauna Loa and other Hawaiian volcanoes for any changes.

The depth, location and recorded seismic waves of the earthquake suggest a source due to the bending of the oceanic plate under the weight of the Hawaiian island chain, a common source of earthquakes in this region. Aftershocks are possible and could be felt.

According to the Pacific Tsunami Warning Center, this earthquake does not threaten a tsunami.

 

Source: HVO

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Publié le par Bernard Duyck
Publié dans : #Sismologia
 Fagradalsfjall - photo Ferlir

 Fagradalsfjall - photo Ferlir

Reykjanes Peninsula - location and magnitude of earthquakes on July 20, 2020 / 06:40 a.m. - IMO doc
Reykjanes Peninsula - location and magnitude of earthquakes on July 20, 2020 / 06:40 a.m. - IMO doc

Reykjanes Peninsula - location and magnitude of earthquakes on July 20, 2020 / 06:40 a.m. - IMO doc

In the Reykjanes Peninsula, an earthquake between M5 occurred at 23:36 in the area of ​​Fagradalsfjall, a tuya formed during the Pleistocene. The earthquake was widely felt in the southwestern part of Iceland.

A considerable number of aftershocks occurred, the most significant were M3.5 at 00:08, M3.4 at 00:55, M3.0 at 02:19 and M3.4 at 03:09 and these were also felt in the southwest of Iceland. .

At 5:46 am, an M4.6 was detected. Rockfall was reported at Festarfjall, about 6 km SW of the epicenter of the earthquake.

On July 18 at 05:56 a.m., an M4.1 earthquake was detected 4.1 km north of Grindavík.

 

Earthquakes around Grindavík have continued in recent months due to deformation in the area.

 

Source: IMO

Location of the Fagradalsfjall tuya in the Reykjanes Peninsula

Location of the Fagradalsfjall tuya in the Reykjanes Peninsula

Fagradalsfjall - Lava flow dating from the Pleistocene - photo Banco imagenes geologicas / Flickr

Fagradalsfjall - Lava flow dating from the Pleistocene - photo Banco imagenes geologicas / Flickr

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

Sernageomin raised the technical alert level of Copahue in Amarilla on July 17 at 3.30 p.m. local time.

During the previous months, the seismicity was marked by numerous VLP earthquakes, in relation with the rise of magma to more superficial levels; in addition, in recent days, signs have been observed on the surface, with the emission of particulate materials associated with a column of gas from the active crater, and incandescence. The satellite images indicate a decrease in the volume of the crater lake ... all these signs testify to my presence of a volume of magma at a superficial level.

An area of ​​1,000 meters in radius around the crater is considered as a possible assignment area.

 

Source: Sernageomn OVDAS

Copahue - 16.07.2020 - ash plume - Mayores Sin Limites video / twitter

Copahue - 16.07.2020 - ash plume - Mayores Sin Limites video / twitter

Copahue - 07.16.2020 - video noticias NQN

The Raung alert level on the island of Java was raised to 2 / waspada on July 17.

Today, between 0 and 6 a.m., a total of 26 brown plumes were observed between 50 and 200 meters above the crater.

The seismicity of July 17 is characterized by :

- 98 eruption earthquakes with an amplitude of 2-17 mm and a duration of 40-155 seconds.

- 83 non-harmonic tremor episodes with an amplitude of 1-5 mm, and a duration of 38-399 sec.

The PVMBG recalls the ban on going down into the crater, and camping within a radius of 2 km in the center of the crater, due to the danger of volcanic gases for life.

 

Sources: PVMBG & Magma Indonesia

 Raung - seismicity at 17.07.2020 - Doc. Magma Indonesia

Raung - seismicity at 17.07.2020 - Doc. Magma Indonesia

In Costa Rica, a passive emission occurred at Turrialba on July 16, 2020 at 12:09 p.m., accompanied by an ash plume 200 meters above the crater; it lasted 2 minutes.

This episode was followed by several other very diluted shows during the day.

A peak in the CO2 / SO2 and H2S / SO2 ratios was recorded overnight, before returning to values ​​similar to those of yesterday.

 

Source: Ovsicori

Turrialba - 07/16/2020 / 12:09 - Ovsicori webcam

Turrialba - 07/16/2020 / 12:09 - Ovsicori webcam

A magnitude 4.1 earthquake occurred 4.1 km from Grindavik, on the Reykjanes Peninsula in Iceland.

It was preceded by another of magnitude 3; 2. Both were felt in Grindavik and Reykjanesbaer.

The persistent seismic activity is, according to the IMO, in relation to the deformation due to magmatic intrusions in the earth's crust.

 

Sources: IMO & mbl, is

Reykjanes peninsula - 07/18/2020 - earthquake magnitude at 07:50 - Doc. IMO

Reykjanes peninsula - 07/18/2020 - earthquake magnitude at 07:50 - Doc. IMO

Grindavík with Mount Þorbjörn in the background. - Doc. mbl.is / Kristinn Magnússon

Grindavík with Mount Þorbjörn in the background. - Doc. mbl.is / Kristinn Magnússon

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Nevados de Chillan - 13.07.2020 in the late evening - glow of the lava flow - photo Josefauna / Volcanologia in Chile

Nevados de Chillan - 13.07.2020 in the late evening - glow of the lava flow - photo Josefauna / Volcanologia in Chile

In Nevados de Chillan, the viscous lava flow emanating from the Nicanor crater continues to descend slowly the northern flank of the volcano.

The Sernageomin has determined a danger zone of 3 km to the west and up to 5 km to the east.

At night, we can notice the glow emitted by the flow; its emission rate is around 0.2m³ / sec.

 

Source: Sernageomin and Volcanologia in Chile

Nevados de Chillan - the lava flow during the day on 14.07.2020 - webcam Sernageomin Portezuelo

Nevados de Chillan - the lava flow during the day on 14.07.2020 - webcam Sernageomin Portezuelo

Also in Chile, on July 14, 2020 at 6:59 am local time, the National Geology and Mining Service recorded an earthquake related to rock fracturing, with a local magnitude of 3.0 and a depth of 0.2 km at Taapaca volcanic complex.

The Complex (5,861 m above sea level) is located on the high plateau of the Arica and Parinacota region, and is in 35th place in the classification of specific risks.

 The Taapaca volcanic complex - photo Daniel Bertin / Sernageomin

The Taapaca volcanic complex - photo Daniel Bertin / Sernageomin

The Complex (5,861 m above sea level) is located on the high plateau of the Arica and Parinacota region, and is in 35th place in the classification of specific risks.

Named locally Nevados de Putre, it corresponds to an elongated volcanic complex with an irregular profile, located on the western edge of the current volcanic front of the central Andes. Its activity dates back 2.7 million years with the emission of lava and mainly andesitic pyroclasts.

Over the past 1.5 million years, eruptive activity has migrated approximately 4 to 5 km to the southwest, limited to short periods of activity and separated by prolonged stages of immobility.

There is no record of historical eruptive activity. There are only hot springs and sulfur deposits associated with this eruptive center.

The alert level remains green; A potential reactivation would be linked to the location of the dacitic domes and to the subsequent generation of pyroclastic currents which would most likely affect the southwest flank of the volcano, the area where Putre is located, the main populated center of the altiplano region. (about 2,000 inhabitants), and the international route CH-11.

 

Source: Sernageomin

 Bulusan - photo archive 2016.10.08 / PHIVOLCS-SPDRRMO

Bulusan - photo archive 2016.10.08 / PHIVOLCS-SPDRRMO

The Phivolcs recorded since July 13 an increase in the number of volcanic earthquakes in Bulusan: it counts 33 in 24 hours on the 13th and 27 earthquakes in 24 hours on the 14th (period from 8h to 8h morning)

A very low emission of white plumes charged with vapor from the southeast vents was observed. Ground deformation data from continuous GPS measurements indicate short-term inflation of the building since late February 2020. These parameters indicate that volcanic processes are underway under the building which may be caused by deep degassing or hydrothermal activity or magmatic intrusion.

People living in the valleys and along the river canals, especially in the south-east, south-west and north-west of the building, must be vigilant against flows and lahars laden with sediment in case of strong prolonged rains.

Level 1 (abnormal) alert status currently prevails over Bulusan volcano, which means that it is currently in an abnormal state.

 

Source: DOST-PHIVOLCS

Iceland - earthquakes at 15.017.2020 / 07.35 am - Doc. IMO
Iceland - earthquakes at 15.017.2020 / 07.35 am - Doc. IMO

Iceland - earthquakes at 15.017.2020 / 07.35 am - Doc. IMO

Vatnajökull / Bárðarbunga - magnitude of the earthquakes on 15.07.2020 - the two earthquakes of more than M3 in the night of 13-14.07.2020 - Doc. IMO

Vatnajökull / Bárðarbunga - magnitude of the earthquakes on 15.07.2020 - the two earthquakes of more than M3 in the night of 13-14.07.2020 - Doc. IMO

Shortly before midnight on July 13 at 11:41 p.m. an earthquake of magnitude 3 shook the southeastern part of the Bárðarbunga caldera and about an hour later on July 14, another earthquake of magnitude 3.6 shook the region.

Earthquakes of this magnitude are common in Bárðarbunga.

 

Note that the seismic swarms continue in the Reykjanes peninsula, around Grindavik, and further north, at the mouth of the Eyjafjördur; In the north, there are more than 13,000 earthquakes, 3 of which are greater than 5.

 

Source: IMO

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Etna - 11.07.2020 - strombolian activity at the "Saddle vent" of the SEC, view of Piano del Vescovo - photo INGVvulcani

Etna - 11.07.2020 - strombolian activity at the "Saddle vent" of the SEC, view of Piano del Vescovo - photo INGVvulcani

A weak Strombolian activity was observed this July 11, 2020 in the evening at the saddle vent located between the new and the old southeast cone of Etna.

 

Source: INGVvulcani

Etna - 12.07.2020 / 06h27 - INGV OE Emot0129 webcam

Etna - 12.07.2020 / 06h27 - INGV OE Emot0129 webcam

A new eruptive episode is reported in Suwanosejima this July 12 at 11:53 am local; it was accompanied by a plume at 1,300 meters above the active crater, drifting to the northeast.

 

Sources: JMA & VAAC Tokyo

Suwanosejima - 12.07.2020 / 11h49 & 11h54 - doc. JMA

Suwanosejima - 12.07.2020 / 11h49 & 11h54 - doc. JMA

Activity fell on Nishinoshima on July 11 and 12.

A slight thermal anomaly remains, but has decreased considerably since July 10, when it was noted at VRP 1340 at 473 MW, against VRP 91 at 8 MW on July 11.

The extension of the plume is centered around the island, with a moderate drift towards the northeast.

 

Sources: Mirova, VAAC Tokyo and Nasa Worldview

Nishinoshima - decrease in thermal anomalies and radiative power - Doc. Mirova on 11.07.2020 / 1.15 p.m. - one click to enlargeNishinoshima - decrease in thermal anomalies and radiative power - Doc. Mirova on 11.07.2020 / 1.15 p.m. - one click to enlarge

Nishinoshima - decrease in thermal anomalies and radiative power - Doc. Mirova on 11.07.2020 / 1.15 p.m. - one click to enlarge

Nishinoshima - 12.07.2020 - Nasa worldview satellite image and Volcanic ash advisory by VAAC Tokyo.
Nishinoshima - 12.07.2020 - Nasa worldview satellite image and Volcanic ash advisory by VAAC Tokyo.

Nishinoshima - 12.07.2020 - Nasa worldview satellite image and Volcanic ash advisory by VAAC Tokyo.

Earthquakes continue in Iceland at the mouth of Eyjafjörður in the north and on the Reykjanes peninsula in the southwest.

 

The seismic swarm at the mouth of Eyjafjörður is still in progress. Since the crisis began on June 19, the National Meteorological Office's earthquake system has located more than 13,000 earthquakes, including three magnitude 5 earthquakes.

There are still many small earthquakes in the region and it is still likely that there will be more larger earthquakes.

 Iceland - earthquakes at 12.07.2020 / 07:15 a.m. - IMO
 Iceland - earthquakes at 12.07.2020 / 07:15 a.m. - IMO
 Iceland - earthquakes at 12.07.2020 / 07:15 a.m. - IMO

 Iceland - earthquakes at 12.07.2020 / 07:15 a.m. - IMO

Yesterday, two earthquakes of more than magnitude 3 were measured just west of Herðubreiðartöglar on the Reykjanes peninsula.

The first of magnitude 3.2 at 2:15 p.m. and the second at 5:47 p.m. of magnitude 3.1, but a report was received that the second earthquake was found in Drekagil by Askja.

Earthquakes have persisted in the Grindavík region in recent months due to landslides.

 

Source: IMO

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Asama - 06.27.2020 / 3:42 p.m. loc. - Osasa Camera, Maechan Net

Asama - 06.27.2020 / 3:42 p.m. loc. - Osasa Camera, Maechan Net

The J.M.A. raised the alert level of Asama, on the island of Honshu in Japan, to 2 / do not approach the crater, on June 25 at 3 p.m. JST. It is advised not to enter the danger zone in the municipalities of Gunma: Tsumagoi-mura, Nagano: Komoro-shi, Karuizawa-machi, Miyota-machi.

Since June 20, seismic activity on the western flank of the volcano has continued at fluctuating levels. On June 24 and 25, the seismic station recorded 59 and 69 volcano-tectonic earthquakes respectively.

An eruption could occur without warning.

The warning bulletin indicates that the ballistic impacts of volcanic bombs and pyroclastic flows could affect an area about 2 km away from the main crater.

Asama - Topography - doc. K. Nakajima / Geological Survey of Japan

Asama - Topography - doc. K. Nakajima / Geological Survey of Japan

Asama could be involved in the famine that marked Europe between 1108 and 1113, according to a recent study on the sulphate deposits of the last millennium in the ice cores of Greenland.

Long considered the product of the 1104 CE Hekla (Iceland) eruption, this event can now be associated with significant deposits observed in Antarctica according to a chronology revised in the same way.

Several closely spaced volcanic eruptions occurred between 1108 and 1110 CE. The sources of these eruptions remain unknown, but the study suggests that Mount Asama, the largest eruption of the Holocene occurred in August 1108 CE (Global Volcanism Program / Asama - eruption of 29.08.1108 at October 1108 - VEI 5 ​​confirmed), and is credibly documented by a contemporary Japanese observer, as a plausible contributor to the high concentration of sulfate in Greenland.

The dendroclimatological data and the historical documentation also attest to serious climatic anomalies following the proposed eruptions, which provided the environmental conditions prior to the subsistence crises experienced in Western Europe between 1109 and 1111 CE.

 

Sources:

- Global Volcanism Program - Asama - eruptive history - link

- Nature - Scientific reports - Guillet, S., Corona, C., Ludlow, F. et al. Climatic and societal impacts of a “forgotten” cluster of volcanic eruptions in 1108-1110 CE. Sci Rep 10, 6715 (2020). - link

- Surveillance cameras - thanks to Yukio Hayakawa

Onioshi camera, Japan Meteorological Agency
Kurogayama Camera, Nagano Prefecture Saku Construction Office
Osasa Camera, Maechan Net
Dodaira Camera, Tokigawa City, Saitama Prefecture

Nishinoshima - 06.26.2020 - strong SO2 signal (38.72DU of SO2 at an altitude of 7.17km. - Doc. Sentinel-5P Tropomi / DLR / BIRA / ESA

Nishinoshima - 06.26.2020 - strong SO2 signal (38.72DU of SO2 at an altitude of 7.17km. - Doc. Sentinel-5P Tropomi / DLR / BIRA / ESA

The VAAC Tokyo reports this June 26 at 12h Z that ash emissions continue in Nishinoshima. Confirmed at an eastward flight altitude of 100 / Himawari-8 satellite data.

A strong sulfur dioxide signal was detected on June 26 from 38.72 DU of SO2 at an altitude of 7.1 km northeast, via Sentinel- 5P / Tropomi.

 

Sources: VAAC Tokyo and Sentinel-5P / Tropomi

Nishinoshima - Volcanic Ash Advisory 26.06.2020 - Doc. VAAC Tokyo

Nishinoshima - Volcanic Ash Advisory 26.06.2020 - Doc. VAAC Tokyo

Ebeko - ash plume - Doc. ASTv / Photo by Sergey Lakomov / 27.06.2020

Ebeko - ash plume - Doc. ASTv / Photo by Sergey Lakomov / 27.06.2020

A moderate eruptive activity continues at the Ebeko, in the Kurils.

According to observations by volcanologists at Severo-Kurilsk, the explosions were accompanied by ash plumes at 2,200 meters asl. on June 25, 2,500 meters asl. on June 26 and more than 1,900 meters asl. on June 27.

The aviation color code remains orange.

 

Source: KVERT

 Tjörnes FZ - location and magnitude of earthquakes at 27.06.2020 / 07:15 - Doc. IMO
 Tjörnes FZ - location and magnitude of earthquakes at 27.06.2020 / 07:15 - Doc. IMO
 Tjörnes FZ - location and magnitude of earthquakes at 27.06.2020 / 07:15 - Doc. IMO

Tjörnes FZ - location and magnitude of earthquakes at 27.06.2020 / 07:15 - Doc. IMO

The seismic swarm in the Tjörnes fracture zone, north-east of Siglufjörður, is still in progress.

During the night of June 27 at 4:52 p.m., an earthquake of magnitude 4.0 was measured at approximately 35 km NNE from Siglufjörður, this morning at 6:02 a.m., another of magnitude 3.2 was measured at approximately 20 km northeast of Siglufjörður.

Yesterday, June 26, the automatic system measured more than 700 earthquakes in the region, an earthquake> 3.0 was detected yesterday at a magnitude of 3.2 at 1:55 p.m. about thirty kilometers northeast from Siglufjörður.

Since the crisis began on June 19, the National Meteorological Office's earthquake system has located about 7,000 earthquakes. Three earthquakes of more than 5 were detected in the hryvnia, the largest on Sunday evening at 7:07 pm magnitude 5.8 at 30 km from Siglufjörður. Other earthquakes larger than 5 were 5.6 and 5.4 and were located more than 20 km NE from Siglufjörður.

Many smaller earthquakes are still measured in the region, and larger earthquakes are likely to occur.

 

Source: IMO - Scientist on duty on 27.06.2020 / 6:17 am

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
 Ebeko - photo Y.Demyanchuk / via RIA Novosti 22.06.2020

Ebeko - photo Y.Demyanchuk / via RIA Novosti 22.06.2020

A moderate eruptive activity is reported by KVERT to the Ebeko on June 21 and 22, 2020, observed by volcanologists from Severo-Kurilsk; it is characterized by explosions which are accompanied by ash plumes at more than 2,000-2,200 meters asl., drifting over 5 km towards the south of the volcano.

 

Source: KVERT - KSCNET & VAAC Tokyo

Sangay - photo archive IGEPN / Patricio Ramon

Sangay - photo archive IGEPN / Patricio Ramon

The levels of surface and internal activity of Sangay in Ecuador remain high, without change.

This June 21, the volcano remains hidden by the clouds, but the VAAC Washington reports gas and ash emissions at 570 meters above the crater, drifting west.

The SAGA seismic station recorded a high frequency signal which is surely associated with the descent of mudslides and debris (lahars).

This phenomenon has been recurrent since the start of activity in May 2019 and is due to the fact that the intense rains over the volcano remobilize the material accumulated during these months of activity. It is recommended not to be in the areas close to the banks of the Volcán and Upano rivers.

In the past 24 hours (20.06 to 21.06 / 11h), the IGEPN reports 8 LP earthquakes, 72 explosions and 8 episodes of emission tremor.

 2019.11.05 Reventador - photo archive IGEPN / Silvana Hidalgo 05.11.2019

2019.11.05 Reventador - photo archive IGEPN / Silvana Hidalgo 05.11.2019

At Reventador, the surface activity is moderate, the internal activity remains high on June 21, 2020.

The cloudiness prevents observation; the VAAC Washington reports during the night of June 20 an emission of gas and ashes at 1,338 meters above the crater, drifting towards the west.

Incandescence is observed at night during the thinnings, as well as falling blocks on the flanks of the volcano over 600 meters.

The IGEPN reports, for the last 24 hours, 23 LP earthquakes, 15 explosions, 5 episodes of emission tremor and 3 of harmonic tremor

 

Sources: IGEPN & VAAC Washington.

Kanlaon - photo Phivolcs

Kanlaon - photo Phivolcs

The Kanlaon Volcano seismic monitoring network recorded one hundred thirty-six volcano-tectonic earthquakes on the western flanks during the latest 24-hour observation period. Four (4) of these earthquakes at 1:01, 1:04, 1:34 and 2:06 were recorded at M3.2-4.7 by the Philippine Seismic Network and were felt at intensities II to V in La Carlota and Bago City, Negros Occidental and Canlaon City, Negros Oriental.

A moderate emission of white plumes loaded with vapor, reaching 200 meters in height, is observed above the crater, before drifting towards the southwest.

Sulfur dioxide emissions were measured at an average of 438 tonnes / day on June 13, 2020. Soil deformation data from continuous GPS measurements indicate inflation on average slopes since April 2020. These parameters indicate that a hydrothermal or magmatic activity occurs under the building.

 

DOST-PHIVOLCS would like to remind the public that the Kanlaon volcano is on alert level 1, which means that it is in an abnormal state and has entered a period of unrest. Local authorities and the public are strongly reminded that entry into the permanent danger zone (PDZ) with a radius of 4 kilometers must be strictly prohibited due to the additional possibilities of sudden and dangerous eruptions of vapor or phreatics.

Source: Phivolcs - 22.06.2020 / 8h

 Tjörnes Fracture zone - location of the seismic swarm and magnitude of earthquakes - Doc. IMO on 06.22.2020
 Tjörnes Fracture zone - location of the seismic swarm and magnitude of earthquakes - Doc. IMO on 06.22.2020
 Tjörnes Fracture zone - location of the seismic swarm and magnitude of earthquakes - Doc. IMO on 06.22.2020

Tjörnes Fracture zone - location of the seismic swarm and magnitude of earthquakes - Doc. IMO on 06.22.2020

The seismic swarm in the Tjörnes fracture zone in northern Iceland continues.

These swarms are common ... what is less so is the unusual high energy released, with more than 70 earthquakes of magnitude greater than 3, the largest reaching M 5.6 and 5.7. In total, the IMO has located more than 2,000 earthquakes since the start of this crisis.

He also reports considerable rock collapses in Tröllaskagi, but also accident reports in Malmö. A power outage in Kelduhverfi was also reported after the second earthquake.

There is a considerable risk of rock accidents and landslides on steep slopes in the northern fjords and on the Tröllaskagi and Flatey Islands. It is important that travelers in the mountains and those traveling in a steep country are aware of the danger of accidents and landslides.

Civil defense has declared the level of uncertainty in the northeast from the start of this seismic swarm.

 

The seismic swarm is still in progress and may move east along the Húsavík-Flateyjarm gang. Larger earthquakes cannot be excluded ... earthquakes of magnitude up to 7 are known in the Húsavík-Flateyjarmenggang. In 1872, there were two earthquakes of magnitude M6.5 and in 1755, an earthquake estimated at M7.

 

Source: IMO - Veðurstofa Íslands

 Tjörnes fracture zone - Rocks fall and landslides - photo 21.06.2020 Veðurstofa Íslands

Tjörnes fracture zone - Rocks fall and landslides - photo 21.06.2020 Veðurstofa Íslands

 NVZ / Northern volcanic zone map - with principal faults and historic earthquakes - via Gisli Olafsson

NVZ / Northern volcanic zone map - with principal faults and historic earthquakes - via Gisli Olafsson

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Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
 Popocatépetl - 02.05.2020 / 11h04 gas and ash exhalation - WebcamsdeMexico

Popocatépetl - 02.05.2020 / 11h04 gas and ash exhalation - WebcamsdeMexico

Cenapred has identified over the past 24 hours at Popocatépetl 142 exhalations and small explosions, accompanied by gas emissions and small amounts of ash, which continued during the day.

A total of 491 minutes of tremor was recorded.

Night glow marked the summit of the volcano, visible on the webcams from 9 p.m. to more than 10:30 p.m.

The volcanic alert remains at amarillo Fase 2.

 

Sources: Cenapred and webcamsdeMexico.

Popocatépetl - incandescence 02.05.2020 / 21h09 - WebcamsdeMexico

Popocatépetl - incandescence 02.05.2020 / 21h09 - WebcamsdeMexico

In Chile, the Sernageomin reports this May 2, 2020 at 7:33 p.m. local to the Puyehue-Cordon Caulle volcanic complex a volcanotectonic earthquake of M loc. 3.0 / depth 3.1 km, associated with the fragmentation of rocks.

The technical alert remains unclear.

The last period of activity dates back to June 2011 - April 2012, characterized by an VEI 5.

 

Source: Sernageomin / OVDAS & Global Volcanism Program

This series of images includes: a) a location map of Puyehue-Cordón Caulle; b) a NASA ALI image taken on January 26, 2012, including the annotated locations of the observation points (red star) and the red box corresponds to the area in "c"; c) the overlapping ventilation structures and ash plumes were captured on this GeoEye-1 image from July 3, 2012; (d) and this panorama of the active lava flow observed on January 10, 2012 (note that the scale is approximate). The original images are from Schipper et al., 2013. / GVP

This series of images includes: a) a location map of Puyehue-Cordón Caulle; b) a NASA ALI image taken on January 26, 2012, including the annotated locations of the observation points (red star) and the red box corresponds to the area in "c"; c) the overlapping ventilation structures and ash plumes were captured on this GeoEye-1 image from July 3, 2012; (d) and this panorama of the active lava flow observed on January 10, 2012 (note that the scale is approximate). The original images are from Schipper et al., 2013. / GVP

In Shishaldin, on advisory volcanic alert and Yellow aviation code, the troubles continue with possible sulfur dioxide emissions detected by satellite and vapor in the crater visible on high resolution satellite images. The views of the web cameras were obscured by the clouds and no significant activity was detected on local seismic stations or regional infrared sensors. Although disturbances are currently at low levels, activity could intensify with little warning, and additional eruptive activity in the summit crater, lava flows, lahars and ash-producing eruptive events could happen.

The Shishaldin is monitored by local seismic and infrasound sensors, satellite data, web cameras, a telemetric geodetic network and remote infrasound and lightning networks.

 

Sources: AVO / 02.05.2020 and Pierre Markuse.

Shishaldin - Sentinel-2 enh image. Nat. Colors + IR overlay / 04.29.2020 - via Pierre Markuse - one click to enlarge

Shishaldin - Sentinel-2 enh image. Nat. Colors + IR overlay / 04.29.2020 - via Pierre Markuse - one click to enlarge

An earthquake with a magnitude of 6.7 and a depth of 10 km. was located by the INGV Tsunami Warning Center (CAT) and EMSC at 12.51 UTC on May 2, 2020. The epicenter is located at sea, about 80 km south of the island of Crete.

The pushing mechanism suggests a break on the subduction interface at shallow depth.

Due to the magnitude, a red tsunami alert (Watch) was issued by the CAT-INGV for the island of Crete, while the alert level is orange (Advisory) for the other regions of Greece, for Turkey, Libya and Egypt. The warning message was issued by CAT-INGV eight minutes after the earthquake.

The CAT-INGV issued a confirmation message of the tsunami, which was observed at the tide gauge of Ierapetra on the island of Crete, although with a extent hitherto limited (approximately 15 cm, or approximately 35 cm at peak). Technically speaking, a sea level change caused by an earthquake has occurred, so it is indeed a tsunami, although small, it caused whirlpool and currents in ports and on beaches.

 

A strong aftershock occurred at 13:33 UTC, characterized by an M 5.3 and a depth of 30 km.

 

Sources: EMSC & CAT-INGV

South Crete - earthquakes of 02.05.2020 / 12.51 and 13.33 UTC - Doc. EMSC
South Crete - earthquakes of 02.05.2020 / 12.51 and 13.33 UTC - Doc. EMSC

South Crete - earthquakes of 02.05.2020 / 12.51 and 13.33 UTC - Doc. EMSC

Earthquake of 02.05.2020 south of crete - location and sea level at Ierapetra (tsunami) - Doc. Dr. Heidarzadeh / Brunel Univ. London

Earthquake of 02.05.2020 south of crete - location and sea level at Ierapetra (tsunami) - Doc. Dr. Heidarzadeh / Brunel Univ. London

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