January 18, 2021. EN . Italy / Sicily : Etna , Saint Vincent : Soufrière Saint Vincent , United States : Mount Hood , Guatemala : Santiaguito .
January 18 , 2021 .
Italy / Sicily , Etna :
VOLCANIC ACTIVITY RELEASE of January 17, 2021, 09:05:44 (UTC) – ETNA.
The National Institute of Geophysics and Volcanology, Osservatorio Etnéo, communicates that since approximately 06:40 GMT, the surveillance cameras show a lava overflow produced by the eastern mouth of the Southeast Crater (CSE). The overflow extends on the eastern flank of the CSE towards the Bove Valley and currently the front is located at about 3000 meters at sea level. Regarding the explosive activity of the summit craters, there is a decrease the frequency of Strombolian explosions at the Southeast Crater (CSE), while the intracrater activity at the Voragine and Bocca Nuova craters remains almost unchanged.
As regards the volcanic tremor, its amplitude oscillates on average to high values, the source is located in the area of the SE Crater between 2.8 and 3 km above sea level.
The infrasound activity in recent hours has shown no significant variation and is localized in the Southeast Crater (CSE) and Voragine region.
No significant change was recorded in the deformation signals acquired by the permanent GPS network.
VOLCANIC ACTIVITY NEWSLETTER of January 17, 2021, 15:06:46 (UTC) – ETNA.
The National Institute of Geophysics and Volcanology, Osservatorio Etneo, announces that with regard to the lava overflow produced by the Southeast Crater and described in the previous press release (# 115), it is announced that At present, due to weather conditions, it is not possible to assess the state of the lava flow. The latest observation available at 12:30 p.m. GMT indicated that the lava front had not progressed from the elevation of around 3,000 meters (above sea level) reported in the previous press release and that the flow of lava seemed to be poorly fed.
As for the explosive activity, it remained unchanged from the previous press release.
The volcanic tremor does not show significant changes compared to the previous press release, with an amplitude on medium-high values, and a location in the area of the Southeast crater at depths between 2.8 and 3 km au above sea level. Infrasound activity over the past few hours has not shown significant changes.
No significant variation was observed in the ground deformation signals recorded by the permanent GPS and tilt networks, just a minimum variation of less than a tenth of a microradian at the ECP tilt station (Crater del Piano) coinciding with the start. of the eruptive event.
Further updates will be communicated shortly.
Source : INGV.
Photos : INGV , Gio Giusa .
Saint Vincent , Soufrière Saint Vincent :
NO EXPLOSIVE ERUPTION AT THE LA SOUFRIÈRE VOLCANO
There is NO ‘explosive’ eruption at the La Soufrière volcano at this time. Neither has an evacuation order been issued.
La Soufrière continues to have effusive eruptions, as hot magma reaches the surface at extreme temperatures. This appears in the night as fire or a bright red glow above the crater. As the dome gets higher and closer to the rim of the crater this phenomenon will continue to be visible on clear nights.
Newly extruded lava at the base of the lava dome.
Visual observations of the Volcano today were limited due to low cloud cover and frequent periods of rain throughout the day. This also did not allow for the completion of the monitoring station on the upper flank of the volcano.
Visual observations of the dome late in the afternoon allowed for clear views into the crater. The dome continues to increase in height, to spread laterally and to emit volcanic gases. The areas of most active gas emission were noted to be the contact areas between the pre-existing 1979 dome and the 2020-21 dome, as well as the top of this new dome.
An extensive area of burnt vegetation was observed in the western section of the crater floor, extending outwards from the dome.
This thermal image of the base of the new dome shows a maximum surface temperature of 590.8 degrees Celsius! Temperatures within the dome will be hotter than those measured at the surface
Analysis of the data from the aerial survey of the dome and from measurement of volcanic gases that were undertaken on Saturday 16th January 2021 was done today by Drs Stinton and Christopher for most of the day.
The electronics team led by Instrumentation Engineer, Lloyd Lynch completed the necessary network connections today to enable the Owia Seismic Station to be brought online. The data is now being transmitted to monitoring scientists. This now brings the total number of seismic stations being used to monitor the volcano to five.
Source : Nemo .
Photos : Nemo / UWI.
United-States , Mount Hood :
January 17, 2021 Mount Hood Earthquake Swarm
An earthquake swarm at Mount Hood is ongoing. The earthquakes are associated with regional faulting and are not a sign of changes in volcanic activity.
Map View of earthquakes at Mount Hood since 2010 (black circles) and the current swarm (red circles), both sized by magnitude. Blue triangles are current seismic stations. Dark lines are highways around the volcano.
Since noon local time on January 17, there have been over 100 individual earthquakes in an area south of the summit of Mount Hood. At the time of this statement, the PNSN has located several 10’s of these earthquakes with a maximum magnitude of M2.7 and depths mostly around 5 km (3 mi) below sea level.
Swarms at Mount Hood are common and account for most of the seismicity at the volcano; they can last hours to days. The location of the earthquakes is similar to other swarms in this area that occurred in 2009, 2012, 2014 and 2020.
Source : USGS.
Photo : Pierson, Tom.
Guatemala , Santiaguito :
According to the analysis of the STG8 station and the observations made by OVSAN on the activity of the Santa María-Santiaguito volcanic complex, it is noted that weak to moderate explosions are recorded at an approximate height of between 3100 and 3300 meters above sea level (10,171 to 10,827 feet), accompanied by constant extrusion of material, accompanied by low noise activity.
In addition, the Caliente dome is observed with a fine white fumarole and generates degassing mainly of water vapor and magmatic gases. The extrusion of block material from the dome of the Caliente dome generates flows of boulders and ash that are directed to the Northwest, West Southwest and East flanks, with the probability that pyroclastic flows are generated. The ashes fall on the volcanic perimeter. (The recommendations of the special bulletin of the Santiaguito volcano 121-2020, remain valid.
Source : Insivumeh .
Photo : Annie Winson , earthobservatory.sg