March 18 , 2017. EN. Etna , Nevado Del Ruiz , Bogoslof , Lanin.
March 18 , 2017.
Etna , Sicily :
ACTIVITY OF ETNA, March 16, 2017
During the eruption in progress since yesterday morning, at 24:43 (local time) today, on 16 March, a phreato-magmatic explosion occurred at the Belvedere (western edge of the Valle del Bove), at about 2700 meters above sea level. The explosion took place at the front of the lava flow that emerges from a vent at the base of the New South-East Crater at about 3200 meters above sea level. Currently the lava is advancing with a temperature above 1000 degrees Celsius in a snow covered area. The snow, in contact with the lava, tends to melt, forming puddles of water that can be covered by the advancing lava.
In this case, the water under the lava flow tends to vaporize and can cause phreatomagmatic explosions like the one that took place today. During this explosive phenomenon, was also involved a volcanologist from the National Institute of Geophysics and Volcanology – Etneo Observatory (INGV-OE), Boris Behncke, who suffered minor bruises. The staff of INGV-OE continue to monitor the evolution of the phenomena continuously.
Source : INGV
Photo : Boris Behncke.
Nevado Del Ruiz , Colombia :
Weekly activity bulletin of the volcano Nevado del Ruiz, March 7-13, 2017
The level of activity continues: at the level activity yellow or (III): changes in the behavior of volcanic activity.
Regarding the monitoring of the activity of the volcano Nevado del Ruiz, the Colombian Geological Survey reports that:
During the week, various monitoring parameters show that the volcano Nevado del Ruiz remains unstable.
Seismic activity related to the fracturing of volcanic rock under the volcano showed an increase in the number of earthquakes and seismic energy released compared to the previous week. This seismicity was located mainly in the South-South West, North-East, South-East and to a lesser extent in the Arenas crater. The depths of the earthquakes varied between 0.8 and 7.4 km. The maximum magnitude recorded in the week was 2.0 ML (local magnitude), corresponding to an event dated March 12 at 22:03 (local time), 3.4 km deep, located 2.4 km South-East of the Arenas crater. A slight increase in activity on 10 March from 15:20 to 16:20 (local time) is distinguished, in which a volcano-tectonic earthquake (VT) of maximum energy (magnitude) 0.8 ML was recorded at 15:28, 2.5 km northeast of the Arenas crater at a depth of 5.0 km
The seismicity related to the dynamics of fluids in the ducts of the volcanic structure was characterized by the appearance of earthquakes with different levels of energy, long period (LP) and very long period (VLP), pulses of tremors and multiple earthquakes of fluids. This type of seismicity has retained the same tendency both in number and in seismic energy released, as observed during the previous week. The earthquakes were mainly located in the Arenas crater, in the south-eastern sector of the volcano and to a lesser extent in the northern sector. Some of these seismic signals have been associated with emissions of gases and ash into the atmosphere, as confirmed by the cameras installed in the volcano region and reports from the Los Nevados National Park (Pnnn) . The recording of such seismic signals with higher energy levels is not excluded, which may be associated with emissions of gas and ash. It is important to remember that ash emission processes can occur over several days and sometimes several times a day, without involving an individual report for each episode.
Volcanic deformation, measured from electronic inclinometers, Global Navigation Satellite Systems (GNSS) and satellite images to determine changes in tilt, position and shape of the volcano, continues to record In recent months a deflationary process and intermittent inflation / deflationary impulses, possibly linked to emissions of ash and gas.
The volcano continues to emit significant amounts of water vapor and gases, including sulfur dioxide (SO2), as evidenced by the values obtained by the SCANDOAS stations installed in the volcanic analysis area and the satellite image. In the tracking information provided by the Mirova site a low-energy thermal anomaly was identified, which was recorded on March 7 with a value of 1.0 MW.
The column of gas, steam and ash from time to time reached a maximum height of 1800 m measured on the top of the volcano on 13 March. The direction of the dispersion of the column was in line with the dominant wind regime in the area, which prevailed during the week to the northwest of the volcano.
The volcano Nevado del Ruiz continues to activity level Amarillo.
Source : Ingeominas
Images : Archives Ingeominas
Bogoslof , Aleutians Islands , Alaska :
53°55’38 » N 168°2’4″ W,
Summit Elevation 492 ft (150 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Bogoslof volcano has been relatively quiet this week since a short-duration eruption on Monday, March 13. The roughly 12-minute-long eruption was preceded by swarm of shallow earthquakes and generated a small ash cloud that was detected in satellite data. The volcanic cloud drifted southwest over Umnak Island about 50 miles beyond the volcano before dissipating. Since the eruption, AVO has not detected any significant seismic activity, but occasional slightly elevated surface temperatures at Bogoslof Island have been observed in satellite data throughout the past week. Warm water above active eruption sites or still hot material from recent eruptive events are possible explanations for the elevated surface temperatures.
Comparison of Bogoslof Island before the 2016-17 eruption to March 11, 2017 configuration. As of March 7-8, 2017, there have been 36 eruptive events since Dec. 12, 2016. Main geographic points of reference are labelled in each image and point A is the same in both images. Image data provided under Digital Globe NextView License.
Seismic network outages from nearby Umnak Island have reduced AVO’s seismic monitoring capabilities, limiting our ability to forecast or rapidly characterize Bogoslof activity. AVO continues to use infrasound (pressure) sensors from Umnak Island and will rely on seismic data from Unalaska Island to monitor Bogoslof, which will still allow for timely detection of significant activity. In addition, we use satellite imagery to track ash clouds and information from the Worldwide Lightning Location Network to identify volcanic lightning. Although we are able to detect significant explosive activity in real-time, there is typically a lag of tens of minutes until we can characterize the magnitude of the event and the altitude of the volcanic cloud.
March 11, 2017 Worldview-2 satellite image of Bogoslof Island showing features and changes resulting from the March 7-8 eruption. A new vent developed on the northwest shore of the island adjacent to the lava dome that formed during the 1992 eruption. Most of the deposits on the surface appear fine grained and were likely emplaced by pyroclastic base surges. The surface of these deposits exhibit ripples, dunes and ballistic impact craters. The scalloped appearing shoreline of the intra-island lake is probably the result of groundwater related erosion (sapping) of the pyroclastic deposits as water refills the lake. Most or all of the water in the lake was likely expelled by the eruption column exiting the primary or other vents. The area of Bogoslof Island in this image is about 0.98 square kilometers. Image data provided under Digital Globe NextView License.
In addition to the significant explosive events we can detect, lower-level eruptive activity may be occurring that is below our ability to detect in seismic, infrasound, and satellite data sources. Low-level activity, if it is occurring, could be explosive and may be generating hazardous phenomena in the immediate vicinity of the volcano.
Source : AVO
Photos : waythomas, chris
Lanin , Chile :
– A total of one hundred and ninety-four (194) seismic events, of which one hundred and ninety-three (193) were classified as long-term (LP) events, primarily associated with transport and fluid dynamics through volcanic conduits and / or because of glacial mass movements were recorded. The largest event had a reduced displacement value of 33 cm2 (RDC) and a local magnitude (ML) of 2.2. In the same way, one (1) volcano – tectonic event (VT) associated with the fracturing of a rigid material exhibited a local magnitude (ML) was classified as M1,0.
– On March 9 from 13:56 to 14:57 GMT, occurred the onset of a long seismic event period (LP), with features similar to those that occurred in February, a total of 42 events of magnitude Local (ML) less than or equal to M2,2 and of reduced displacements (RDC) of less than 33 cm2.
– The images provided by the IP cameras installed around the volcano showed no surface changes.
– No anomalies in sulfur dioxide (SO2) emissions to the atmosphere in the volcanic field area have been reported, according to data from the ozone monitoring instrument (IMO group http: // so2 .gsfc .nasa.gov /) and NESDIS (http://satepsanone.nesdis.noaa.gov).
– No thermal alerts were reported in the area associated with the volcano according to MODIS’s MODVOLC (Resolution Imaging Moderate spectroradiometer) data on its website (http://modis.higp.hawaii.edu/) and Mirova Medium Observation InfraRed) on its website (http://www.mirovaweb.it/).
During the period under review, new seismic swarms were recorded similar to those recorded in the previous month, mainly characterized by a temporary increase in LP events of low energy, similar to those recorded during the previous month . This type of activity is unusual for this volcanic system, suggesting a change in internal dynamics, without moving towards an instability of the volcanic system. However, it is possible that this process may evolve in unstable states, so that the level of volcanic alert remains at:
YELLOW LEVEL: changes in the behavior of volcanic activity – probable time for an eruption: weeks / months.
Source : Sernageomin
Photos : Sernageomin , Terras Patagonicas .