Overblog
Suivre ce blog Administration + Créer mon blog

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
Piton de La Fournaise - the OVPF teams in the field give the scale - photo 30.09.2022 OVPF

Piton de La Fournaise - the OVPF teams in the field give the scale - photo 30.09.2022 OVPF

The eruption started at Piton de La Fournaise on 09/19/2022 around 07:48 local time continues.

The amplitude of the eruptive tremor (indicator of surface lava emission) has been increasing since 9:40 p.m. local time yesterday (5:40 p.m. UTC). This intensification is very certainly linked to an increase in pressure within the eruptive cone which first led to the widening of the opening of the main mouth of the cone then to an increase in activity of the secondary mouth (to the south of the main cone) around 23:15 local time.

Piton de La Fournaise - Evolution of the RSAM (indicator of a surface lava emission) since 09/19/2022 00:00 UTC time (04:00 local time) on the RVA seismological station located at the Rivals crater (© OVPF/IPGP ).

Piton de La Fournaise - Evolution of the RSAM (indicator of a surface lava emission) since 09/19/2022 00:00 UTC time (04:00 local time) on the RVA seismological station located at the Rivals crater (© OVPF/IPGP ).

The images from the OVPF-IPGP webcam located at Piton de Bert show since 11:15 p.m. local time yesterday evening a lava projection activity greater than the previous days at the level of the eruptive site, with an enlargement of the main eruptive mouth and secondary.

Degassing is still observed at the eruptive site

the majority of lava flows are still through lava tunnels within which many resurgences are visible; lava flows also occur directly from the secondary mouth.

The lava flow estimates established by satellite method on the HOTVOLC (OPGC - Clermont Auvergne University) and MIROVA (University of Turin) platforms indicate an average flow over the last 24 hours relatively stable and low around 2-4 m³/s. As lava flow activity now takes place primarily in tunnels, these estimates are minimum values.

A main flow of fluid lava formed and was advancing eastward at about 150 meters per hour yesterday.

Piton de La Fournaise - the eruptive site on 09.30.2022 / 05:45 UT - webcam Piton de Bert 4 / OVPF - one click to enlarge

Piton de La Fournaise - the eruptive site on 09.30.2022 / 05:45 UT - webcam Piton de Bert 4 / OVPF - one click to enlarge

Piton de La Fournaise - For comparison: shooting of the eruptive site on September 28, 2022 around 3 p.m. (local time). The main mouth was more closed and the secondary mouth (on the left in the photo) was already visible but of small size (©OVPF-IPGP).

Piton de La Fournaise - For comparison: shooting of the eruptive site on September 28, 2022 around 3 p.m. (local time). The main mouth was more closed and the secondary mouth (on the left in the photo) was already visible but of small size (©OVPF-IPGP).

The processing by stereophotogrammetry of the images acquired by the OVPF-IPGP teams on September 28, 2022 made it possible to estimate the size of the eruptive cone. It was at this date, at its highest point, about 27 m high and 87 m wide.

A volcano-tectonic earthquake was recorded directly above the summit area over the past 24 hours.

The resumption of slight inflation (swelling) over the entire volcano (summit and enclosure) is confirmed but remains of very low intensity for the moment (< 1 cm).

Alert level: Alert 2-1 (Access to the Enclosure prohibited; eruption in the Enclosure without any particular threat to the safety of persons, property or the environment)

 

Source: OVPF-IPGP

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

Piton de La Fournaise - 3D reconstruction by stereophotogrammetry of the eruptive cone from images (drone) acquired on September 28, 2022 (©OVPF-IPGP).

Piton de La Fournaise - 3D reconstruction by stereophotogrammetry of the eruptive cone from images (drone) acquired on September 28, 2022 (©OVPF-IPGP).

In Suwanosejima, there were 7 explosions on September 29 and 5 on September 30 until 3:00 p.m. In addition, large volcanic blocks are sometimes observed reaching about 500m from the center of the crater.
The volcanic plume accompanying the eruption rose up to 1,500m above the crater rim and a glowing glow was observed at night.
According to the Fukuoka District/Toshima Village Meteorological Observatory, about 5 km south-southwest of Mitake Crater, rumbling and falling tephra have been confirmed.
At 0036 and 17:51 on September 29, a large volcanic earthquake occurred and an earthquake intensity of 1 was observed with the epicenter on the west side of Suwanosejima.

Minor fluctuations were observed suggesting an increase in magma accumulation.
Volcanic earthquakes on the western side of the island, including large ones, continue to occur.
Vigorous eruptive activity will continue in the future, and a large volcanic eruption will occur within a radius of about 2 km from the center of Mitake Crater, according to the JMA report.

 

Source: JMA – information on the situation of the volcano on September 30, 2022 / 4 p.m. / Fukuoka District Meteorological Observatory/Kagoshima Local Meteorological Observatory.

Suwanosejima - explosion of 09.30.2022 / 17:17-18 - JMA webcam

Suwanosejima - explosion of 09.30.2022 / 17:17-18 - JMA webcam

A minor, passive ash emission from an active vent behind crater lake at Whakaari/White Island observed on Sunday September 18 has not been seen since.

The North Rim web camera continues to produce views of the crater area and regular checks by our National Geohazard Monitoring Center have shown no ash emissions. Observations from the TropOMI satellite which images sulfur dioxide (SO2) once a day have shown no signal from Whakaari/White Island since Sunday 18 September.
In recent days, images from the North Rim camera have become less clear. This is a normal result of the island vapor plume drifting over the camera and depositing a thin, salty film on the camera's protective cover. Images remain bright enough to provide useful views of the active crater area. The thin, salty film will often disappear with the next heavy rain.

Whakaari - activity downing - alert remains at 2 - GeoNet webcam comparative views 18.09.2022 & 28.09.2022 - one click to enlarge

Whakaari - activity downing - alert remains at 2 - GeoNet webcam comparative views 18.09.2022 & 28.09.2022 - one click to enlarge

GeoNet has previously suggested that the minor, passive emission of ash and sulfur dioxide on Sunday September 18 was most likely due to a small, shallow batch of magma releasing its gas and carrying small magma fragments with it. The absence of other ash or sulfur dioxide emissions since confirms this conclusion. There is no evidence of increased activity at Whakaari/White Island.

The VAL remains at Level 2 (Moderate to Intense Disorder), acknowledging the current level of activity, but also continuing to recognize the greatest level of uncertainty in our interpretation due to the current lack of consistent and useful real-time data. The Aviation Color Code is lowered to yellow, reflecting a reduced likelihood of minor ash emissions.

 

Source: GeoNet

Reykjanes ridge - earthquake of 01.10.2022 / 01:18 UTC and regional seismicity - Doc. EMSC automatic location (2)

Reykjanes ridge - earthquake of 01.10.2022 / 01:18 UTC and regional seismicity - Doc. EMSC automatic location (2)

The seismic swarm, which started in the southern part of the Reykjanes Ridge about 4 days ago, continues, with about 80 events recorded between magnitude 4.5 to 5.9.

 

 

Citizen
Response

 

 

 

 

Date & Time 

UTC

Latitude

degrees

Longitude

degrees

Depth

km

Mag

[+]

Region name

[+]

 

 

 

 

 

2022-10-01   04:58:04.21hr 52min ago

53.81 

N  

35.30 

W  

10

4.8

 REYKJANES RIDGE

 

 

 

 

2022-10-01   02:06:09.54hr 44min ago

53.91 

N  

35.28 

W  

10

5.0

 REYKJANES RIDGE

 

 

 

 

2022-10-01   01:18:53.95hr 31min ago

53.75 

N  

35.51 

W  

10

5.9

 REYKJANES RIDGE

 

 

 

 

2022-09-30   19:52:05.510hr 58min ago

53.92 

N  

35.33 

W  

10

4.8

 REYKJANES RIDGE

 

 

 

 

2022-09-30   12:50:09.9

54.07 

N  

35.29 

W  

10

4.8

 REYKJANES RIDGE

 

 

 

 

2022-09-30   12:21:07.3

53.62 

N  

35.18 

W  

10

4.6

 REYKJANES RIDGE

 

 

 

 

2022-09-30   11:38:53.2

53.54 

N  

35.34 

W  

10

4.6

 REYKJANES RIDGE

 

Bold : Earthquakes with a magnitude ≥ 4.5 in Euro-med, or ≥ 5.5 in the world
Red : Earthquakes with a magnitude ≥ 5 in Euro-med, or ≥ 6 in the world

Sources: USGS earthquake hazards program and EMSC

Lire la suite

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Sangay - ash emission on 27.09.2022 / 06:53 loc. - cam ECU911 / IGEPN - one click to enlarge

Sangay - ash emission on 27.09.2022 / 06:53 loc. - cam ECU911 / IGEPN - one click to enlarge

Sangay - 27.09.2022 / 6:20 UTC - GOES-16 ABI / NOAA image

Sangay - 27.09.2022 / 6:20 UTC - GOES-16 ABI / NOAA image

From 01:00 TL, September 27, 2022, thanks to satellite images (GOES-16), an ash cloud is observed which reaches about 2 km above the crater of the Sangay volcano, Ecuador, and headed towards the southwest.

Therefore, there is a possibility of ash fall in the province of Chimborazo. This phenomenon has persisted during the current eruptive period which began in May 2019.

The IG-EPN continues to monitor the event and will report in a timely manner if changes in seismic signals are detected.

 

In the past 24 hours, the Washington VAAC has issued 3 reports of ash emissions in a west and northwest direction with a maximum height of 2,400 meters above crater level.
Frequent small columns of ash were observed during the day.
The FIRMS system records 34 thermal alerts and MIROVA records 2 high thermal alerts (239 and 196 MW) in the last 24 hours.
This morning, thanks to the images shared by ECU-911, the volcano was clear, an emission of ash could be observed 800 meters above the summit in a southwesterly direction. At the moment, the volcano is cloudy.
Seismicity is significant, with 825 explosion earthquakes (EXP), 12 Long Period earthquakes (LP), and 22 emission earthquakes (TREMI)
The alert remains at the Amarilla level.

 

Source: IGEPN

Home Reef - volcanic events of 09.27.2022 (red dots), and ash eruption (gray dot) - Doc. VOLCAT via TGS

Home Reef - volcanic events of 09.27.2022 (red dots), and ash eruption (gray dot) - Doc. VOLCAT via TGS

In the Pacific, the geological service of the Tonga Islands reports for September 27, 2022 a total of 21 volcanic events at Home Reef, including an ash eruption at 12:36 p.m., imaged by the Himawari-8 satellite.

No new measurements from the new island since September 19: 211 m. x 218m. Surface: 8.6 acres / 34800 m², estimated height: 15 m. asl.

Notice for the navy: do not enter waters within a radius of 4 km. around Home Reef

 

Source: Tonga Geological Services

Piton de La Fournaise - shooting of the eruptive site on September 27, 2022 at 1:55 p.m. local time. On the left the cone in formation since the beginning of the eruption on September 19, on the right the peak Kalla Pélé (eruption August-October 2015) (©OVPF-IPGP) - one click to enlarge

Piton de La Fournaise - shooting of the eruptive site on September 27, 2022 at 1:55 p.m. local time. On the left the cone in formation since the beginning of the eruption on September 19, on the right the peak Kalla Pélé (eruption August-October 2015) (©OVPF-IPGP) - one click to enlarge

The amplitude of the eruptive tremor (indicator of surface lava emission) at Piton de La Fournaise has remained generally stable over the past 24 hours, at around 20% of its initial amplitude.

No volcano-tectonic earthquake has been recorded directly above the summit area over the past 24 hours.

Piton de La Fournaise - The amplitude of the eruptive tremor (indicator of surface lava emission) to station  has remained generally stable over the past 24 hours / as of 27.09.2022 (©OVPF-IPGP)

Piton de La Fournaise - The amplitude of the eruptive tremor (indicator of surface lava emission) to station has remained generally stable over the past 24 hours / as of 27.09.2022 (©OVPF-IPGP)

A slight inflation (swelling) of the summit zone of the volcano seems to be emerging, this parameter will be confirmed in the coming days.

The lava flow estimates established by satellite method on the HOTVOLC (OPGC - Clermont Auvergne University) and MIROVA (University of Turin) platforms indicate an average flow over the last 24 hours that is relatively stable and low around 2 m3/s, with a maximum peak rated at 7 m3/s.

The observations of the OVPF-IPGP teams in the field show for today an activity similar to the previous days.

Alert level: Alert 2-1 (Access to the Enclosure prohibited; eruption in the Enclosure without any particular threat to the safety of persons, property or the environment)

 

Source: OVPF-IPGP

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

Vulcano - INGV photo archives

Vulcano - INGV photo archives

At Vulcano, in the Aeolian Islands, temperatures remain stable at high values ​​along the upper edge of the crater.
The CO2 flux in the crater area remains stable at medium-high values.
The SO2 flux in the crater area is stable at a moderately medium-high level
Geochemistry of fumarolic gases: The concentration of magmatic species (CO2, He, N2) is slightly decreasing (11 mol% CO2 on 09/14/2022).
The CO2 flux at the base of the La Fossa cone and in the Vulcano Porto area: stable CO2 flux values ​​above the background noise in the Rimessa site; stable but still abnormal values ​​on the Camping Sicilia site; slightly decreasing values ​​at the Palizzi site (P4max); in the Faraglione site the values ​​recorded are stable and close to the baseline values
Monthly CO2 Flux Campaign: C emissions in the Vulcano Porto area show no significant change from the previous month and still remain at levels above background.

Vulcano - spatial distribution of CO2 flux from the ground on 20.09.2022 - Doc. INGV OE

Vulcano - spatial distribution of CO2 flux from the ground on 20.09.2022 - Doc. INGV OE

The INGV reports a stabilization of the supply of fluids of fumarolic origin to the thermal aquifer is generally observed, but still remains at abnormal levels in certain sites.

The other parameters do not show significant variations.

 

Source: INGV OE – full text https://buff.ly/3LPH6Zo

Reykjanes Ridge - seismic swarm and its location: A seismic swarm takes place south of the Reykjanes Ridge, in the Atlantic at the Charlie-Gibbs transform fault, and reveals a possible magmatic intrusion. Source: USGS Earthquake Hazards, via @EQuake_Analysis - one click to enlargeReykjanes Ridge - seismic swarm and its location: A seismic swarm takes place south of the Reykjanes Ridge, in the Atlantic at the Charlie-Gibbs transform fault, and reveals a possible magmatic intrusion. Source: USGS Earthquake Hazards, via @EQuake_Analysis - one click to enlarge

Reykjanes Ridge - seismic swarm and its location: A seismic swarm takes place south of the Reykjanes Ridge, in the Atlantic at the Charlie-Gibbs transform fault, and reveals a possible magmatic intrusion. Source: USGS Earthquake Hazards, via @EQuake_Analysis - one click to enlarge

A seismic swarm takes place south of the Reykjanes Ridge, in the Atlantic at the level of the Charlie-Gibbs transform fault, and reveals a possible magmatic intrusion.

 

Source: USGS Earthquake Hazards

Lire la suite

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

At the Piton de la Fournaise, after almost 3 days of decrease, the amplitude of the eruptive tremor (indicator of a lava emission on the surface) gradually re-engaged during last night. Its level stabilized during the day at around 20% of its initial amplitude.

Seismicity under the summit area remains very low with 1 single volcano-tectonic earthquake recorded over the last 24 hours.

Piton de la Fournaise - Evolution of the RSAM (indicator of a lava emission on the surface) since 19.09.2022 / 00h00 UTC time (04:00 local time) at 22.09.2022- Doc. OVPF

Piton de la Fournaise - Evolution of the RSAM (indicator of a lava emission on the surface) since 19.09.2022 / 00h00 UTC time (04:00 local time) at 22.09.2022- Doc. OVPF

Piton de la Fournaise - During a thinning - OVPF photo

Piton de la Fournaise - During a thinning - OVPF photo

Thanks to an improvement in weather conditions for a few hours yesterday afternoon, a team from the observatory was able to go to the eruptive site with the support of the Air Force Section of the Gendarmerie and the Gendarmerie Platoon of Haute Mountain. This intervention allowed:
- to confirm the precise location of the eruptive vent: A main mouth animated by a lava fountain about 20 m high, in the central part of the crack, and two more modest mouths are active. A small cone leans against the Kalla Pélé piton.
- to take a sample of lava in the flow near the vent,
- to take a sample of older projections,
- to evaluate the lava flow at about 3 m³/s.

Estimates of lava flow were established by satellite method on the HOTVOLC platform (OPGC - Clermont Auvergne University), during yesterday afternoon (peaks at 2.5 m³ / sec), as well as this morning at the favor of short thinnings (peak at 3.6 m³/s).

At the end of the day yesterday, the images from the OVPF-IPGP webcams showed a very marked decrease in activity focused on the lowest part of the crack system which opened on Monday.

Due to the very bad weather conditions on the Fournaise massif on 22.09, no on-site reconnaissance could be carried out by the OVPF-IPGP teams, whether on foot or by air. Overcast weather continues today.

 

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

 

Source: OVPF

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

Sheveluch - 23.09.2022 / 07:41 - IVS webcam

Sheveluch - 23.09.2022 / 07:41 - IVS webcam

Sheveluch - volcanic re-suspended ash advisory at 23.09.2022 / 0600Z - Doc. VAAC Tokyo

Sheveluch - volcanic re-suspended ash advisory at 23.09.2022 / 0600Z - Doc. VAAC Tokyo

The growth of the Sheveluch lava dome continues; strong fumarolic activity, incandescence of the lava dome, explosions and hot avalanches accompany this process. Video and satellite data by Kvert showed a thermal anomaly over the volcano.

The resuspended ash plume extended 430 km east of the volcano.

 

Source: KVERT and VAAC Tokyo

Tectonic context of Samoa and Ta'u island - image Sentinel-2 Copernicus / GVP-12401
Tectonic context of Samoa and Ta'u island - image Sentinel-2 Copernicus / GVP-12401

Tectonic context of Samoa and Ta'u island - image Sentinel-2 Copernicus / GVP-12401

The Taʻū island related earthquake swarm continues, with seismicity remaining weak over the past week. The position of the source of the earthquake has not changed. Three earthquakes were reported in the past week, with magnitudes similar to larger earthquakes earlier in this swarm. Satellite data from the previous week observed no volcanic activity.

The National Earthquake Information Center (NEIC) will soon begin publishing the preliminary locations of the largest earthquakes that occurred during this period of seismic unrest in American Samoa. Earthquake locations and depths are currently best estimates, with large uncertainties resulting from the fact that the monitoring network is limited to the east-west orientation of the islands of American Samoa.

Current volcanic alert level: Advisory
Current Aviation Color Code: Yellow

 

Source: USGS/HANS

Tjörnes Fracture Zone - location and magnitude of earthquakes as of 23.09.2022. / 07:55 - Doc. IMO
Tjörnes Fracture Zone - location and magnitude of earthquakes as of 23.09.2022. / 07:55 - Doc. IMO
Tjörnes Fracture Zone - location and magnitude of earthquakes as of 23.09.2022. / 07:55 - Doc. IMO

Tjörnes Fracture Zone - location and magnitude of earthquakes as of 23.09.2022. / 07:55 - Doc. IMO

The seismic swarm over the Tjörnes Fracture Zone, which began on September 8, continues to decline.

More than 12 thousand earthquakes have been detected since the start of the swarm. When the swarm intensity was at its highest, a thousand earthquakes were detected each day, but the past two days several hundred earthquakes have been recorded per day.

The Ministry of Civil Protection and Emergency Management announced a level of uncertainty for ongoing seismic activity in North Iceland on September 9, 2022.


Source: IMO, written by a specialist as of 21 Sep 09:35 GMT

Lire la suite

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

The Home Reef submarine volcano in the central Tonga Islands re-emerged above sea level on Saturday, September 10, 2022.

The detection was first made by VOLCAT on September 10 at 01:39, and confirmed by Sentinel-2 images at 12:29.

The eruption is fumarolic, and releases gases more than a kilometer high; no volcanic ash is detected.

Home Reef submarine volcano eruption &t& first detected by VOLCAT on 10.09.2022 / 01:39 - Doc. Tonga Geological Services - one click to enlarge

Home Reef submarine volcano eruption &t& first detected by VOLCAT on 10.09.2022 / 01:39 - Doc. Tonga Geological Services - one click to enlarge

Home Reef - image Sentinel-2 L2A highlight optimized natural color from 10.09.2022 / 1:59 p.m. - Doc. Copernicus / via Tonga Geological Services - one click to enlarge

Home Reef - image Sentinel-2 L2A highlight optimized natural color from 10.09.2022 / 1:59 p.m. - Doc. Copernicus / via Tonga Geological Services - one click to enlarge

Home Reef is located 25 km away. southwest of Late island, and 22 km. northeast of Lateiki.

Its re-emergence forms an area of ​​approximately 1 acre / 4056 m², with a diameter of 70 meters and an estimated elevation of 10 m. above sea level.

Last eruption in 2006.

The danger is for maritime navigation, which must remain 3 km away. from Home Reef.

 

Source: Tonga Geological Services, Government of Tonga.

3D bathymetric model of the island arc of the Tonga Archipelago, with known volcanic eruptions since 2000 - Brandl Philipp - one click to enlarge

3D bathymetric model of the island arc of the Tonga Archipelago, with known volcanic eruptions since 2000 - Brandl Philipp - one click to enlarge

The sequence of earthquakes beneath the central part of Lake Taupō (Taupō-nui-a-Tia), New Zealand, continues at a rate of about 40 to 50 earthquakes per week. Since the start of the sequence in May 2022, the pace has increased from 30 events per week to more than 40 per week. We have now located more than 650 earthquakes less than 30 km deep.

The M 4.2 earthquake on Saturday morning September 10 is the biggest event this year in Taupō. It was reported felt by 1242 people. The next two largest earthquakes were both magnitude 3.6; the first was recorded on May 17 and the other on July 11, 2022. Since 2000 we have located 7 earthquakes greater than magnitude 4 below the lake, the largest was a M 5.0 on September 4, 2019 located near Motutaiko Island. Saturday's earthquake was 8 km northeast of this 2019 quake.

Earthquakes located by GeoNet in the Lake Taupō region from January 1 to September 12, 2022. All earthquakes presented here were located less than 30 km deep. There are over 650 earthquakes shown on the map - Doc. GeoNet

Earthquakes located by GeoNet in the Lake Taupō region from January 1 to September 12, 2022. All earthquakes presented here were located less than 30 km deep. There are over 650 earthquakes shown on the map - Doc. GeoNet

Earthquakes detected and located in the dotted area delineated on the map every year since 2000. The sequence of earthquakes of 2022 stands out, at this point the numbers exceed the sequences of 2009, are almost equal to those of 2008 and remain lower than those of 2019. - Doc. GeoNet - one click to enlarge

Earthquakes detected and located in the dotted area delineated on the map every year since 2000. The sequence of earthquakes of 2022 stands out, at this point the numbers exceed the sequences of 2009, are almost equal to those of 2008 and remain lower than those of 2019. - Doc. GeoNet - one click to enlarge

In addition to seismic activity, GeoNet continuously monitors ground deformation around Taupō. Following the 12 mm uplift observed from lake leveling data, deformation data from GNSS (GPS) instruments around the lake also show a signal indicating horizontal deformation. Numerical modeling indicates that the horizontal extension is consistent with a source of deformation in the main region of seismic activity.

The Taupō Volcanic Center is part of the Taupō Volcanic Zone, a tectonically highly active region with numerous known faults and active volcanism. Activity in this region is often linked to a mix of regional deformation processes and the separate magmatic systems beneath the volcanoes, which has helped inform our view that Volcanic Alert Level 0 is currently appropriate for the volcanic center of Taupō, and remains at level 0.

 

Source: GeoNet – 14.09.2022

Stromboli - S2 mouth ash explosion - INGV OE on 13.09.2022. - one click to enlarge

Stromboli - S2 mouth ash explosion - INGV OE on 13.09.2022. - one click to enlarge

During the week of September 5-11, normal Strombolian-type explosive activity was observed at Stromboli. The total hourly frequency of explosions varied on low values, from 3-5 events/h. The intensity of the explosions was low and medium in both the North Crater area and the Center-South Crater area.
Weak and infrequent (sometimes simultaneously) ash emissions were observed from at least 2 vents located near the S2 crater, sometimes associated with little coarse material.


The seismological parameters monitored do not show any significant variations.
The soil deformation monitoring networks in operation on the island did not show any significant variations during the period studied.
The flow of SO2 at an average and increasing level; the flux of CO2 from the soils in the summit zone is on average values.
The C/S ratio in the plume settles on average values ​​(9.5)
Isotope ratio of dissolved He in heat sinks: there is no update from the July 27, 2022 sampling.
Thermal activity observed by satellite in the summit area was weak.

 

Source : INGV OE  - put online on 13.09.2022

Map of the seabed of the epicenter of the earthquake in Grímsey - earthquakes reviewed by IMO in black and in black and earthquakes 2020-2022 in gray - Doc. via Jarðvísindastofnun Háskólans / 13.09.2022

Map of the seabed of the epicenter of the earthquake in Grímsey - earthquakes reviewed by IMO in black and in black and earthquakes 2020-2022 in gray - Doc. via Jarðvísindastofnun Háskólans / 13.09.2022

More than 8250 earthquakes have been detected since the start of activity in Grímsey. The largest earthquake detected was an M4.9 on September 8 at 04:00. The largest earthquakes were widely felt in northern Iceland. The last major seismic swarm in this area dates back to February 2018.

A seabed map of the earthquake's epicenter in Grímsey has just been uploaded The map shows recent earthquakes according to the IMO seismic table in black and 2020-2022 earthquakes in gray , drawn according to their size. The northernmost part of the ridge north of Grímsey originates at Nafirnar. In this volcanic area, you can see mountains and lava formed after the ice age. The Grímsey earthquake started on the south side of Nafnar, then moved southeast along a broad north-trending sag at Skjálfandadjupi, then back to Nafnar.

The Department of Civil Protection and Emergency Management announced a level of uncertainty for ongoing seismic activity in North Iceland on September 9, 2022.

Source: IMO 13.09.2022 / 15:17 GMT & Jarðvísindastofnun Háskólans

Tjörnes FZ - location and magnitude of earthquakes as of 09.13.2022 / 3:45 p.m. - Doc. IMO
Tjörnes FZ - location and magnitude of earthquakes as of 09.13.2022 / 3:45 p.m. - Doc. IMO
Tjörnes FZ - location and magnitude of earthquakes as of 09.13.2022 / 3:45 p.m. - Doc. IMO

Tjörnes FZ - location and magnitude of earthquakes as of 09.13.2022 / 3:45 p.m. - Doc. IMO

Lire la suite

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Popocatépetl - exhalation with ashes on 09.11.2022 / 10:44 a.m. - Mexico City webcams - one click to enlarge

Popocatépetl - exhalation with ashes on 09.11.2022 / 10:44 a.m. - Mexico City webcams - one click to enlarge

During the past 24 hours, thanks to the monitoring systems of the Popocatépetl volcano, 69 exhalations have been detected accompanied by water vapor, volcanic gases and slight amounts of ash. Additionally, 37.5 minutes of shaking were recorded.

During the morning and until 11 a.m., it was not possible to observe the crater of the volcano continuously due to cloudy conditions in the region, however, some emissions were observed in a northwest direction.

CENAPRED urges not to approach the volcano and especially the crater, because of the danger of falling ballistic fragments and, in the event of heavy rains, to stay away from the bottom of the ravines because of the danger of lava flows. mud and rubbish.

The volcanic alert of Popocatépetl remains in Amarillo Fase 2

 

Sources : Cenapred & webcamsdeMexico

Poas - vigorous convection and fumaroles on 09.09.2022 / 08:16 - Webcam Ovsicori - one click to enlarge

Poas - vigorous convection and fumaroles on 09.09.2022 / 08:16 - Webcam Ovsicori - one click to enlarge

The thermal convection of the Laguna Caliente du Poas and the fumarolic degassing without eruptive activity are maintained.

Between 07:00 and 08:00 on September 11, very vigorous convection was observed around the new mouth on the north side of the lake.

Seismicity is maintained with a background tremor. The maximum SO2 concentration observed at the belvedere was 3.4 ppm this morning. Gas ratios remain stable and no significant change in deformation behavior is observed.

The volcano shows slight but significant vertical uplift and some horizontal extension around the crater, which is more marked at the level of the GPS geodetic station in the visitors' building.

 

The Ovsicori observed an increase in volcanic activity, which may be a precursor to a period of phreatic eruption, as in 2019 or 2014. This change in activity occurs in a tectonic context with an earthquake in the subduction zone .

Activity Level: Warning (2)

 

Source: Ovsicori – Daily information and communication on a change in activity from 09.09

Reventador - 2022.09.11 / 08:51 local time - Emission of steam and ash. - webcam Rebecca / IGEPN

Reventador - 2022.09.11 / 08:51 local time - Emission of steam and ash. - webcam Rebecca / IGEPN

Reventador - Radiative power as of 09.12.2022 / 02:55 - Doc. Mirova_MODIS_logVRP

Reventador - Radiative power as of 09.12.2022 / 02:55 - Doc. Mirova_MODIS_logVRP

Reventador's surface and internal activity levels remain moderate, and unchanged.

Seismicity is characterized by 40 long-period earthquakes (LP), 49 explosion earthquakes (EXP), 15 episodes of emission tremor (TREMI), 3 episodes of harmonic tremor (TRARM)

On the morning of September 11, an emission of gas and ash from a height of 700 meters above the level of the crater in a northwest direction could be observed. No alert was recorded by the VAAC agency in Washington.

The FIRMS and MIROVA satellite systems have not recorded any thermal anomalies on the volcano in the past 24 hours. In the early hours of today, luminosity was observed in the crater. At the moment, the area is cloudy.

The state of the volcano's alert level - SNGRE: Orange

 

Source: IGEPN

Tjörnes Fracture Zone - location and date of earthquakes as of 12.09.2022 / 07:05 - Doc. IMO
Tjörnes Fracture Zone - location and date of earthquakes as of 12.09.2022 / 07:05 - Doc. IMO

Tjörnes Fracture Zone - location and date of earthquakes as of 12.09.2022 / 07:05 - Doc. IMO

Seismic disturbances have been occurring in the Tjörnes Fracture Zone since early September.
The Icelandic Meteorological Office (IMO) reported that more than 6,000 earthquakes have been recorded under the island of Grímsey so far, the strongest of which was detected with a magnitude M 4.9 on September 8 at 04:01. local time, widely felt in northern Iceland. .
The offshore Tjörnes Fracture Zone is an oblique transform zone that separates the volcanic zone of northern Iceland from the Kolbeinsey Ridge, which is part of the Mid-Atlantic Ridge in northern Iceland.

 

Source: IMO

Tjörnes Fracture Zone - magnitude of the earthquakes of 09, 10, 11 and 12.09.2022 - Doc. IMO
Tjörnes Fracture Zone - magnitude of the earthquakes of 09, 10, 11 and 12.09.2022 - Doc. IMO
Tjörnes Fracture Zone - magnitude of the earthquakes of 09, 10, 11 and 12.09.2022 - Doc. IMO
Tjörnes Fracture Zone - magnitude of the earthquakes of 09, 10, 11 and 12.09.2022 - Doc. IMO

Tjörnes Fracture Zone - magnitude of the earthquakes of 09, 10, 11 and 12.09.2022 - Doc. IMO

Lire la suite

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Popocatépetl - explosion on 09.09.2022 / 03:45 - Mexico City webcams - one click to enlarge

Popocatépetl - explosion on 09.09.2022 / 03:45 - Mexico City webcams - one click to enlarge

Popocatépetl - explosion on 2022.09.09 / 05:25 - Mexico City webcams - one click to enlarge

Popocatépetl - explosion on 2022.09.09 / 05:25 - Mexico City webcams - one click to enlarge

During the last 24 hours, 70 exhalations have been detected at Popocatépetl, accompanied by water vapor, volcanic gases, ashes and sometimes incandescent fragments, as well as 167 minutes of low amplitude tremor and three volcano-earthquakes. tectonics were recorded today at 3:33 a.m., 3:34 a.m. and 3:36 a.m., with magnitudes of 1.7, 1.6, and 1.8, respectively.

The Popocatepetl volcano in Mexico presented 3 explosions on September 9, respectively at 03:44, 05:22, and 06:13; the latter was accompanied by an eruptive column of more than 2,000 meters above the crater, with dispersion towards Puebla-Morelos. They seem to be due to seismic energy and amplitude.


The volcanic alert is unchanged at Amarillo Phase2

 

Sources: Cenapred & webcams from Mexico

Anak Krakatau - night glow in  the dome on 09.09.2022 / 23h45 WIB - webcam Sertung  / PVMBG

Anak Krakatau - night glow in the dome on 09.09.2022 / 23h45 WIB - webcam Sertung / PVMBG

Anak Krakatau volcano is clearly visible this September 9, 2022, until it is covered by fog 0-III. The main crater's observable plume is white, with fine to medium high intensity about 25-100 meters from the summit. The weather is cloudy to cloudy, the wind is weak in the north, northeast and northwest.

Seismicity is characterized on September 9 by:
- 2 emission/gust earthquakes, with an amplitude of 6-7 mm, and the duration of the earthquake was 15-21 seconds.
- 22 low frequency earthquakes, with an amplitude of 3 to 11 mm and the duration of the earthquake is 3 to 9 seconds.
- 5 shallow volcanic earthquakes, with an amplitude of 3 to 10 mm and an earthquake duration of 5 to 10 seconds.
- 3 deep volcanic earthquakes, with an amplitude of 30-48 mm, S-P 2.2-3.6 seconds and an earthquake duration of 9-13 seconds.
- 4 episodes of continuous tremor, with an amplitude of 0.5 to 10 mm, dominating 2 mm.

The level of activity at 3/siaga, with a recommendation for communities/visitors/tourists/climbers not to approach Anak Krakatau or engage in activities within 5 km of the active crater.

 

A Volcanodiscovery group approached the dome and noticed its incandescence and the presence of numerous fumaroles.

 

Sources: PVMBG, Magma Indonesia, Mounts project

Anak krakatau - plume and incandescence at the lava dome on 09.09.2022 / 03:05 - image Sentinel-2 bands 12,11,8A via Mounts project

Anak krakatau - plume and incandescence at the lava dome on 09.09.2022 / 03:05 - image Sentinel-2 bands 12,11,8A via Mounts project

Between September 2 and September 8, 2022, the BPPTKG recorded 20 lava avalanches at Merapi; they were observed in a dominant southwest direction towards the Bebeng River with a maximum slip distance of 1,700 m.

No significant morphological changes were observed at the domes. According to the analysis of the photos, the volume of the southwest dome is 1,624,000 m³ and that of the central dome is 2,772,000 m³.

 Merapi - summit zone 02 - 08.09.2022 - Doc. BPPTKG

Merapi - summit zone 02 - 08.09.2022 - Doc. BPPTKG

The intensity of the earthquakes this week is still quite high. 528 Deep Volcanic Earthquakes (VTA), 19 Shallow Volcanic Earthquakes (VTB), 239 Multiphase Earthquakes (MP), 450 Abortion Earthquakes (RF), 76 Blowing Earthquakes (DG ), 1 earthquake and 8 tectonic earthquakes (TT).

The prevailing seismic intensity was in the form of a VTA earthquake which indicated magmatic activity at a depth of >1.5 km from the summit.

Mount Merapi's deformation, which was monitored using EDM this week, showed a distance shortening rate of 0.2 cm/day.

The activity level remains at 3/Siaga, with the usual no-go zones.

 

Source: BPPTKG

Merapi - seismicity and deformation from 09.02.2022 to 09.08.2022 - Doc. BPPTKG

Merapi - seismicity and deformation from 09.02.2022 to 09.08.2022 - Doc. BPPTKG

Thousands of earthquakes have been recorded since September 7 in the Tjörnes fracture zone in northern Iceland.

According to Böðvar Sveinsson, a natural disaster expert at the Icelandic Meteorological Bureau, there are no signs of an eruption. There are two seismic zones, the Húsavíkur-Flateyjar fault zone and the Grímsey fault zone, and earthquakes are common in these zones. A similar earthquake occurred there in 2018.

The National Police Commissioner, in consultation with the North East Police Chief, has stated the level of public safety uncertainty due to the earthquake in the north. There is also heightened scrutiny of scenarios which, at a later stage, may lead to a threat to human health and safety, the environment or habitat.

 

Sources: IMO & RUV

Tjörnes fracture zone - location of earthquakes on 10.09.2022 - magnitude of earthquakes on 09 and 10.09.2022 - Doc. IMO
Tjörnes fracture zone - location of earthquakes on 10.09.2022 - magnitude of earthquakes on 09 and 10.09.2022 - Doc. IMO
Tjörnes fracture zone - location of earthquakes on 10.09.2022 - magnitude of earthquakes on 09 and 10.09.2022 - Doc. IMO
Tjörnes fracture zone - location of earthquakes on 10.09.2022 - magnitude of earthquakes on 09 and 10.09.2022 - Doc. IMO

Tjörnes fracture zone - location of earthquakes on 10.09.2022 - magnitude of earthquakes on 09 and 10.09.2022 - Doc. IMO

Tjörnes fracture zone - Trémor at Grimsey station on 10.09.2022 - Doc. Hraun.vedur

Tjörnes fracture zone - Trémor at Grimsey station on 10.09.2022 - Doc. Hraun.vedur

Lire la suite

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Piton de La Fournaise - 02.09.2022 / 04:55 UT - CameraPartage / OVPF- IPG - one click to enlarge

Piton de La Fournaise - 02.09.2022 / 04:55 UT - CameraPartage / OVPF- IPG - one click to enlarge

The OVPF informs us that the period from August 1 to 27, 2022 was marked at Piton de La Fournaise by low seismicity at the level of Piton de la Fournaise with an average of 3 superficial volcano-tectonic earthquakes per day.

Since August 28, 2022, an increase in seismicity has been observed under the Piton de la Fournaise: 20 volcano-tectonic earthquakes were recorded on August 28, 24 on August 29, 41 on August 30 and 31 on August 31.

The inflation of the summit continued.

A decrease in CO2 fluxes in the soil was recorded both in the near and distal field.

 

The inflation which resumed in June, and which continued in July and August, was witness to a weak recharge and a weak pressurization of the superficial magmatic reservoir by upwellings of deep fluids.

The appearance of seismicity at the roof of the reservoir since the end of August shows that this pressurization process is intensifying.

This process of recharge from the depths to the superficial reservoir can take several days to several weeks before the reservoir roof weakens and ruptures, thus giving rise to an injection of magma towards the surface and an eruption, but can also stop without giving rise - in the short term - to an eruption.

 

Source: OVPF

Piton de La Fournaise - Histogram representing the number of superficial volcano-tectonic earthquakes recorded since August 1, 2022 (© OVPF)

Piton de La Fournaise - Histogram representing the number of superficial volcano-tectonic earthquakes recorded since August 1, 2022 (© OVPF)

Piton de La Fournaise: Illustration of the deformation over the last six months. The variations in distance between two GPS receivers crossing the Piton de la Fournaise building are shown here, at the top (reference BOMG; top), at the base of the terminal cone (reference FOAG; middle) and in the far field (reference PRAG; bottom). A rise is synonymous with elongation and therefore swelling of the volcano; conversely a decrease is synonymous with contraction and therefore deflation of the volcano (© OVPF-IPGP).

Piton de La Fournaise: Illustration of the deformation over the last six months. The variations in distance between two GPS receivers crossing the Piton de la Fournaise building are shown here, at the top (reference BOMG; top), at the base of the terminal cone (reference FOAG; middle) and in the far field (reference PRAG; bottom). A rise is synonymous with elongation and therefore swelling of the volcano; conversely a decrease is synonymous with contraction and therefore deflation of the volcano (© OVPF-IPGP).

Update on the seismovolcanic activity recorded on the island of São Jorge, in the Azores archipelago, as of 09/1/2022 10:00

The Azores Seismovolcanic Information and Monitoring Center (CIVISA) informs that the seismovolcanic activity recorded on the island of S. Jorge since 4:05 p.m. (local time = UTC-1) on March 19 continues above normal , extending, roughly, along a strip with WNW-ESE direction, from Ponta dos Rosais to the area of ​​Norte Pequeno – Silveira.

So far, about 50,146 small-scale events of tectonic origin have been recorded. Between 12:00 a.m. and 10:00 a.m. today, about 68 earthquakes were recorded. The most energetic earthquake of this crisis occurred on March 29, at 21:56 (local time = UTC), had an epicenter about 2 km SSW of Velas and a magnitude 3.8 (Richter). So far, about 318 earthquakes felt by the population have been recorded.

Overall, the seismic activity of the last few weeks shows a slight downward trend, sometimes interrupted by short periods of higher frequency and / or released energy, the hypocenters being currently located, in general, at depths greater than 5 km.

São Jorge - seismicity as of 09.01.2022 - Doc. CIVISA

São Jorge - seismicity as of 09.01.2022 - Doc. CIVISA

São Jorge - Daily frequency of recorded earthquakes - Doc. IVAR - CIVISA 01.09.2022

São Jorge - Daily frequency of recorded earthquakes - Doc. IVAR - CIVISA 01.09.2022

As part of the geodetic monitoring, the existing data since the beginning of April do not show any significant deformation in the epicentral zone.

The gas and temperature measurement campaigns in the soil that have been carried out since the beginning of this crisis in the epicentral zone have not, to date, led to the identification of anomalies resulting from the seismovolcanic activity. , now the field surveys.

Hydrogeochemical campaigns in groundwater from the two monitoring boreholes (Queimada II and Ribeira do Nabo - IROA) did not reveal any significant variations that could be associated with the ongoing seismovolcanic crisis.

The integration of the available information allows us to conclude that the tectonic structures where the historic eruptions of 1580 and 1808 took place, and the seismovolcanic crisis of 1964, in the Fissural Volcanic System of Manadas, have been reactivated, and it must be admitted that at the beginning of the phenomenon there was a deep magmatic intrusion.

The decrease in seismic activity, although slow, and the observation of such a pattern in recent weeks, as well as the absence of other anomalous signs in terms of deformation, gases and waters, have led CIVISA to determine, on June 8, the scientific alert level was raised from V4 to V3 on the island of S. Jorge. However, seismic activity continues well above baseline values ​​for the region, so the possibility of recording felt events remains and the possible occurrence of higher magnitude earthquakes cannot be ruled out.

CIVISA maintains monitoring levels on the island of S. Jorge and ensures the reinforcement of the permanent seismovolcanic observation network, in the sense that, if the pattern of activity reverses, it can detect the precursor signs of a new pre-eruption situation.

 

Source: http://www.ivar.azores.gov.pt/ - CIVISA

Revue Nature - 01.09.2022 - "Under the volcano", the mechanism behind the unexpected eruption of Nyiragongo.

Revue Nature - 01.09.2022 - "Under the volcano", the mechanism behind the unexpected eruption of Nyiragongo.

An article in the journal Nature on the eruption of Nyiragongo in May 2021 reveals the underside of the flank eruption. It is the result of a collaboration between 36 scientists from 11 different countries (26 different affiliations). Here is the summary :

" Classical mechanisms of volcanic eruptions primarily involve the buildup of pressure and the rise of magma to the surface1. Such processes produce geophysical and geochemical signals that can be detected and interpreted as eruption precursors1,2,3.

On May 22, 2021, Mount Nyiragongo (Democratic Republic of the Congo), an open-vent volcano with a persistent lava lake perched in its summit crater, challenged this interpretation by producing a roughly six-hour flank eruption with no apparent precursors. , followed - rather than preceded - by lateral movement of magma in the crust.

We show here that this reverse sequence was most likely initiated by a rupture of the edifice, producing lethal lava flows and triggering a voluminous intrusion of 25 km long dykes. The dyke propagated southward at very shallow depths (less than 500 m) below the cities of Goma (Democratic Republic of Congo) and Gisenyi (Rwanda), as well as Lake Kivu.

This volcanic crisis raises new questions about the mechanisms controlling such eruptions and the possibility of coping with much more dangerous events, such as outpourings within densely urbanized areas, phreato-magmatism or a limnic eruption from Lake Kivu. in gas. It also highlights more generally the challenges open vent volcanoes face for monitoring, early detection, and risk management when a large volume of magma is stored near the surface.”

 

Source: Smittarello, D., Smets, B., Barrière, J. et al. Precursor-free eruption triggered by edifice rupture at Nyiragongo volcano. Nature 609, 83–88 (2022). https://doi.org/10.1038/s41586-022-05047-8 – In Nature 01,09,2022

This is an open access article distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Nyiragongo - a, COSMO-SkyMed (CSK) interferogram from May 21, 2021 at 3:37 PM UTC to May 22, 2021 at 3:37 PM UTC showing no obvious deformation less than 1 hour before the start of the eruption. . b, Comparison of PlanetScope46 images of Nyiragongo crater between March 27, 2021 and August 9, 2021. c, Daily eastward movements recorded at permanent GNSS stations KBT (blue) and RBV (orange) (see location on map a) from April 1, 2021 to June 30, 2021. d, Daily count of seismic events automatically detected and located (meeting the selection criteria defined in the Methods) from April 1, 2021 to June 30, 2021 and 12-hour moving median of the measurement real-time seismic amplitude (RSAM) filtered between 2 Hz and 10 Hz at permanent seismic stations NYI (green) and KBTI (blue). / Nature ref. abo

Nyiragongo - a, COSMO-SkyMed (CSK) interferogram from May 21, 2021 at 3:37 PM UTC to May 22, 2021 at 3:37 PM UTC showing no obvious deformation less than 1 hour before the start of the eruption. . b, Comparison of PlanetScope46 images of Nyiragongo crater between March 27, 2021 and August 9, 2021. c, Daily eastward movements recorded at permanent GNSS stations KBT (blue) and RBV (orange) (see location on map a) from April 1, 2021 to June 30, 2021. d, Daily count of seismic events automatically detected and located (meeting the selection criteria defined in the Methods) from April 1, 2021 to June 30, 2021 and 12-hour moving median of the measurement real-time seismic amplitude (RSAM) filtered between 2 Hz and 10 Hz at permanent seismic stations NYI (green) and KBTI (blue). / Nature ref. abo

Lire la suite

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Taal Volcano - plume of gas and steam - photo CNNPH 03.08.2022

Taal Volcano - plume of gas and steam - photo CNNPH 03.08.2022

Taal volcano - sulfur dioxide or SO2 flux data for 2022 and since the 2020 eruption (inset). - Doc. Phivolcs 03.08.2022

Taal volcano - sulfur dioxide or SO2 flux data for 2022 and since the 2020 eruption (inset). - Doc. Phivolcs 03.08.2022

Taal - summary of activity as of 02.08.2022 / 05:00 - Doc. Phivolcs

Taal - summary of activity as of 02.08.2022 / 05:00 - Doc. Phivolcs

Four episodes of volcanic tremor, which lasted from 2 to 7 minutes, have been detected in Taal Volcano in the past 24 hours, the Philippine Institute of Volcanology and Seismology announced on Tuesday. The flow of sulfur dioxide averaged 12,125 tons/day on August 3. A prolific degassing in the main crater of Taal has been perceptible for three days; it causes hot volcanic fluids to rise in the lake and emit steam-rich plumes that rise 2,400 meters from Volcano Island.

Phivolcs director Renato Solidum Jr. told the Philippine News Agency that the tremors had nothing to do with the magnitude 7 earthquake that shook northern Luzon last week.


The alert level remains set at 1 (low level disturbances).

Below Alert Level 1, sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall and volcanic gas expulsions could threaten areas within the Taal Permanent Hazard Zone.
Entry into the permanent danger zone, especially around the main crater and the Daang Kastila fissure, remains prohibited. Occupancy and boating on Lake Taal is also prohibited.

 

Sources: Phivolcs, PNA Philippines, CNN PH

Reykjanes Peninsula - seismicity / location and magnitude of earthquakes as of 08.03.2022 / 10:30 a.m. - Doc. Icelandi Met Office
Reykjanes Peninsula - seismicity / location and magnitude of earthquakes as of 08.03.2022 / 10:30 a.m. - Doc. Icelandi Met Office
Reykjanes Peninsula - seismicity / location and magnitude of earthquakes as of 08.03.2022 / 10:30 a.m. - Doc. Icelandi Met Office

Reykjanes Peninsula - seismicity / location and magnitude of earthquakes as of 08.03.2022 / 10:30 a.m. - Doc. Icelandi Met Office

Update on the situation in the Reykjanes Peninsula:

a magnitude 5.0 earthquake occurred at 2:27 a.m. on August 2, 2022, just west of Lake Kleifarvatn. The earthquake was widely felt in the southwest of the country. Seismicity increased on the Reykjanes Peninsula around 11 p.m. last night. The activity is now located just west of Lake Kleifarvatn.

Grímsvötn's color code was changed to yellow this 02.08 due to multiple M>1 events detected this afternoon, the largest Mw 3.6 event at 14:24 UTC. This means that the seismicity of the volcano is higher than normal activity, which requires increased monitoring of the area.

The largest earthquake since the start of the seismic swarm on Saturday was of a magnitude 5.4 which occurred on Sunday at 5:48 p.m. It was located just 3 km NE of Grindavík. A total of 15 events of magnitude greater than 4 have been detected and they are located from Mount Þorbjörn to Lake Kleifarvatn.

Reykjanes Peninsula - InSAR image made from Sentinel-1 satellite images and covering the period from July 20 to August 1, 2022 - Doc. IMO

Reykjanes Peninsula - InSAR image made from Sentinel-1 satellite images and covering the period from July 20 to August 1, 2022 - Doc. IMO

A small glow visible on mblfrettir's camera turned out to be a small moss fire, origin to be determined.

The probability of an eruption increased in the Reykjanes peninsula in the late afternoon, with the presence of magma at 1km depth according to Vedurstofan. Surface deformation also continues.

 

At 05:32 on August 3, a magnitude 4.6 earthquake was located east of Fagradalsfjall. The earthquake was felt in Grindavík, Reykjanesbær, the capital region, and Selfoss.

Deformation and seismicity appear to be slowing down. This pattern was observed last year, just before the eruption.

 

Sources: IMO & Icelandic volcanoes

Sabancaya - activity from 25 to 31.07.2022 - photo I.G.P.

Sabancaya - activity from 25 to 31.07.2022 - photo I.G.P.

The I.G.Peru mentions the maintenance of the activity of Sabancaya, between July 25 and 31, 2022, at moderate levels, with an average of 27 daily explosions, accompanied by plumes of gas and ash up to 2,300 m. above the top.

Seismicity is up slightly, with a total of 320 earthquakes of volcanic origin associated with the circulation of internal magmatic fluids, and VT earthquakes, related to rock fracturing.

No significant deformation anomalies; eight thermal anomalies were identified, with a max. of 21 MW, associated with the presence of a lava dome in the crater.

The alert remains in naranja, with the maintenance of an inaccessible zone of 12 km radius around the crater.

 

Source: I.G.P.

Lire la suite

Publié le par Bernard Duyck
Publié dans : #Sismologia
Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 07.31.2022 / 6:25 p.m. - Doc. IMO
Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 07.31.2022 / 6:25 p.m. - Doc. IMO
Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 07.31.2022 / 6:25 p.m. - Doc. IMO

Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 07.31.2022 / 6:25 p.m. - Doc. IMO

Small seismic swarm update in Reykjanes Peninsula.

At 03:14, an earthquake of magnitude M4.3 was detected about 4 km SSW of Fagradalsfjall. At 03:41 an earthquake of M4.2 was detected about 4 km N of Grindavík. At 4:51 a.m., an M4.4 earthquake occurred about 3.3 km northwest of Grindavík. Many earthquakes greater than M3 have been detected this evening.

Yesterday at 5:48 p.m. an earthquake of magnitude M5.4 occurred about 3 km ENE of Grindavík. It was felt east to Fljótshlíð and west to Snæfellsnes. This earthquake was a trigger earthquake, due to magma intrusion by Fagradalsfjall.


Nearly 3,000 earthquakes have been recorded since noon yesterday, including 50 of magnitude 3 and four of magnitude M4. GPS data suggests that the earthquake swarm is caused by the movement of magma under the ground. Sigríður Kristjánsdóttir, who is also a natural hazard expert, said the Met believed there was lateral movement of magma occurring at a depth of 5-7 km. The Met was paying close attention to any changes in the depth of the seismic activity, particularly if it became more shallow, "as this would indicate that the magma is pushing a little higher".

To be continued ...

 

Sources: IMO & RUV

Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 01.08.2022 / 05:45 - Doc. IMO
Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 01.08.2022 / 05:45 - Doc. IMO
Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 01.08.2022 / 05:45 - Doc. IMO

Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 01.08.2022 / 05:45 - Doc. IMO

Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 01.08.2022 - Doc. via Sigríður Kristjánsdóttir

Reykjanes Peninsula current seismic swarm - location of earthquakes and magnitude as of 01.08.2022 - Doc. via Sigríður Kristjánsdóttir

Lire la suite

Publié le par Bernard Duyck
Publié dans : #volcanic activity, #Sismologia
Fuego - Landsat images - 9 bands 7,6,2 of 30.07.2022 - Doc. Insivumeh - un clic pour agrandir

Fuego - Landsat images - 9 bands 7,6,2 of 30.07.2022 - Doc. Insivumeh - un clic pour agrandir

The Fuego volcano observatory, the OVFGO, reports a weak plume at a height of 4,800 meters above sea level which disperses in a west and south-west direction. Incandescent pulses were observed at a height of 200 meters above the crater, these generate avalanches on the edge of the crater of weak to moderate characteristics. Faint sounds similar to those of a train locomotive continue to be heard constantly.

The lava flow towards the barranca Ceniza has a length of about 1.2500 meters according to the image of the Landsat-9 satellite.

It generates, at the flow front, constant weak to moderate avalanches. During the descent of these avalanches, an ash curtain is raised with a height of 500 meters from the surface, which is scattered to the west and southwest.

As a result of this activity, ash falls are reported in the areas of Panimaché I, Morelia, Santa Sofía, El Porvenir, Sangre de Cristo, Finca Palo Verde, Yepocapa and others. Due to the variability of the wind, there is a probability of ash fall in communities northwest of the volcano, such as Quisaché and neighboring communities.

 

Source : Insivumeh 30.07.2022 / 07:39 local

La Palma - opening of a road in the Tajogaite lava flows / Cumbre vieja - photo archives I Love the World

La Palma - opening of a road in the Tajogaite lava flows / Cumbre vieja - photo archives I Love the World

The Cabildo de La Palma will open the La Laguna - Las Norias highway to traffic, in both directions, continuously and without vehicle type restrictions, starting next Monday, August 1, between 6:30 a.m. and 10:00 p.m. , reports the institution in a press release. Pedestrian access is prohibited.

The opening in both directions of traffic, in the established time slot, maintains a series of rules with which traffic has been regulated, such as the prohibition to stop along the route of the road. A speed limit of 20 km/h will be established and there will be permanent monitoring on the road.

 

Source: https://www.eldiario.es/canariasahora

Fagradalsfjall - location and magnitude of earthquakes as of 07.30.2022 / 2:35 p.m. - Doc. IMO
Fagradalsfjall - location and magnitude of earthquakes as of 07.30.2022 / 2:35 p.m. - Doc. IMO
Fagradalsfjall - location and magnitude of earthquakes as of 07.30.2022 / 2:35 p.m. - Doc. IMO

Fagradalsfjall - location and magnitude of earthquakes as of 07.30.2022 / 2:35 p.m. - Doc. IMO

Around noon on July 30, a powerful series of earthquakes with lots of small seismic activity started just northeast of Fagradalsfjall, a short distance north of Fagradalsraun.

The strongest earthquake in the series was measured at a magnitude of 4.0 at 2:03 p.m. Earthquakes are now measured at a depth of about 5-7 km.

Tremors were recorded in Reykjanesbær, Grindavík, Höfðuborgarsvæðinu and as far as Borgarnes. It is believed that these earthquakes are due to a flow of magma which is located northeast of Fagradalsfjall at a depth of 5 to 7 km.
Because of this seismic swarm, there is an increased risk of rockfalls. Several earthquakes have already been measured above magnitude 3, and in earthquakes like this, landslides can occur. There have been no reports of recent rockfalls in the area yet. If there are more powerful earthquakes, the probability of a rockfall increases. People are advised to be careful on steep slopes, near steep cliffs, and to avoid areas where rocks may cave in. The National Police Commissioner, in cooperation with the Suðurnesj Police Commissioner, has declared a level of uncertainty

Civil Defense notification and a yellow VONA for Krisuvik have been issued. The National Weather Service is monitoring progress closely.

Fagradalsfjall - location and magnitude of earthquakes on 07.30.2022 / 5.20 p.m. and 07.31.2022 / 07.55 a.m. - Doc. IMO - one click to enlargeFagradalsfjall - location and magnitude of earthquakes on 07.30.2022 / 5.20 p.m. and 07.31.2022 / 07.55 a.m. - Doc. IMO - one click to enlarge
Fagradalsfjall - location and magnitude of earthquakes on 07.30.2022 / 5.20 p.m. and 07.31.2022 / 07.55 a.m. - Doc. IMO - one click to enlargeFagradalsfjall - location and magnitude of earthquakes on 07.30.2022 / 5.20 p.m. and 07.31.2022 / 07.55 a.m. - Doc. IMO - one click to enlarge

Fagradalsfjall - location and magnitude of earthquakes on 07.30.2022 / 5.20 p.m. and 07.31.2022 / 07.55 a.m. - Doc. IMO - one click to enlarge

As of July 31/7am, IMO has already located more than 2,500 earthquakes, relating to the seismic swarm in the Reykjanes Peninsula NE of the 2021 eruption site at Fagradalsfjall.

No signs of a volcanic eruption were seen on Met Office gauges, or any other signs that an eruption has started or is currently imminent, the Met Office says. (mbls)

Mýrdalsjökull - location and magnitude of earthquakes on 30.07.2022 / 09:55 - Doc. IMO
Mýrdalsjökull - location and magnitude of earthquakes on 30.07.2022 / 09:55 - Doc. IMO
Mýrdalsjökull - location and magnitude of earthquakes on 30.07.2022 / 09:55 - Doc. IMO

Mýrdalsjökull - location and magnitude of earthquakes on 30.07.2022 / 09:55 - Doc. IMO

Note : A magnitude 4.2 earthquake was measured on July 29, 2022 at 10:58 p.m. south of the Mýrdalsjökull glacier, followed by around ten earthquakes of lesser magnitude. It was felt at Mýrdalshreppur.

The Mýrdalsjökull caps the Katla volcano.
 

 

Sources: IMO & mbls

Lire la suite

1 2 3 4 5 6 7 8 > >>

Archives

Articles récents

Hébergé par Overblog