June 08 , 2017 . EN . Nevado Del Ruiz , Bogoslof , Pavlof , Villarica .

Home / Alaska / June 08 , 2017 . EN . Nevado Del Ruiz , Bogoslof , Pavlof , Villarica .

June 08 , 2017 . EN . Nevado Del Ruiz , Bogoslof , Pavlof , Villarica .

June 08 , 2017 .

Nevado Del Ruiz , Colombia :

Weekly activity bulletin of the volcano Nevado del Ruiz, May 30 to June 5, 2017
The level of activity continues: yellow (III) activity level: changes in the behavior of volcanic activity.

As regards the monitoring of the activity of the Nevado del Ruiz volcano, the Colombian Geological Survey reports that:

Over the past week, the various monitoring parameters show that the Nevado del Ruiz volcano continues to exhibit unstable behavior.

The seismicity caused by the fracturing of the rock showed a decrease in the number of recorded earthquakes and the seismic energy released compared to the previous week. The earthquakes were predominantly in the Northeast and South-East sectors, and to a lesser extent in the North, and in the Arenas crater, at depths between 0.5 and 7.6 km. The maximum magnitude recorded during the week was 1.0 ML (local magnitude), which corresponds to an earthquake recorded on June 05 at 23:49 (local time), located 1.3 km north-east of the crater Arenas, at a depth of 3.7 km.

 

The seismic activity associated with fluid dynamics inside the volcano ducts showed a decrease from the energy levels reported the previous week. This type of activity is mainly characterized by the presence of several fluid earthquakes, long-term and very long-period events, and tremor pulses with varying energy levels and durations. Some of these seismic signals have been associated with ash emissions into the atmosphere, as confirmed by the cameras installed in the volcano region and by the reports of NPPN officials and civil aviation. The recording of seismic signals of this type, with higher energy levels that may be associated with emissions of gas and ash are not excluded. It is important to remember that the ash emission processes can occur for several days and sometimes several times during the 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 inclination, position and shape of the volcano, continues to record a deflationary process and intermittent inflation / deflation  impulses, possibly linked to emissions of gases and ash.

 

The volcano continues to emit significant amounts of water vapor and gases, including sulfur dioxide (SO2), as shown by the values obtained by the SCANDOAS stations installed in the volcano zone, and analysis of satellite images. In the tracking information provided by the Mirova portal and the SAGIR a low-energy thermal anomaly, 2 MW, was identified on 31 May.

The column of gas, steam and ash from time to time reached on June 3rd a maximum height of 1300 m above the top of the volcano. The direction of dispersal of the column was in line with the direction of the wind in the region, which predominated during the week towards the Northwest and West Volcano.

The volcano Nevado del Ruiz continues to activity level Amarillo.

 

Source : Ingeominas

Photos : Archives

 

Bogoslof , Alaska :

AVO/USGS Volcanic Activity Notice

Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Issued: Wednesday, June 7, 2017, 7:05 AM AKDT
Source: Alaska Volcano Observatory
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

L’image contient peut-être : océan, ciel, plein air, eau et nature

Volcanic Activity Summary:
A short duration explosive event occurred at Bogoslof volcano at 14:30 UTC on June 7 (6:30 am AKDT). Seismic signals indicate that this event was slightly larger than a similar explosion detected at Bogoslof yesterday morning The duration of the event was about 2 minutes, and seismicity returned to low levels following the explosion. No volcanic cloud has been seen in satellite data as of 14:30 UTC. Due to the brevity of the event, the Aviation Color Code remains at ORANGE and the Volcano Alert Level remains at WATCH.

This level of activity is consistent with the current Aviation Color Code of ORANGE and the Volcano Alert Level of WATCH.

Recent Observations:
[Volcanic cloud height] None observed in satellite data through 14:30 UTC
[Other volcanic cloud information] Unknown

 

AVO/USGS Volcanic Activity Notice
Issued: Wednesday, June 7, 2017, 4:25 PM AKDT
Volcanic Activity Summary:
A new lava dome has been observed in satellite data from earlier today. It is located in the northern portion of the vent lagoon, has breached sea level, and is about 110 m across. A robust steam plume is visible in satellite data, and at 2250 UTC (14:50 AKDT) extended for 75 km to the south over the western end of Unalaska Island at an estimated altitude of less than 10,000 ft asl.

 

AVO Image

Photograph of volcanic plume from Bogoslof, taken by crew of USFWS R/V Tiglax, from about 30 miles away. Photo was taken at about 6:30 P.M., AKDT, June 5, 2017.

Some past eruptions of Bogoslof have ended with the emplacement of a lava dome, but in other cases, lava effusion has been followed by additional explosions. If future explosions do occur, the resulting volcanic cloud could be more ash-rich than those that have occurred thus far in the sequence that began in 2016.

This level of activity is consistent with the current Aviation Color Code of ORANGE and the Volcano Alert Level of WATCH.

Recent Observations:
[Volcanic cloud height] Less than 10,000 ft asl
[Other volcanic cloud information] Steam-rich
[Lava flow/dome] New lava dome observed
[Lava flow] N/A

 

Volcanic Activity Summary:
A short duration explosive event occurred at Bogoslof volcano at 5:28 UTC on 8 June (21:28 AKDT on 7 June). Seismic and infrasound signals indicate that this event was very similar to the event from earlier today at 14:30 UTC. The duration of the event was less than 2 minutes, and seismicity and infrasound returned to low levels following the explosion. A small steam-rich volcanic cloud is visible in satellite data, rising no more than 10,000 ft asl. Due to the brevity of the event, the Aviation Color Code remains at ORANGE and the Volcano Alert Level remains at WATCH.

Source : AVO

Photos : AVO

 

Pavlof , Alaska :

AVO/USGS Volcanic Activity Notice

Current Volcano Alert Level: ADVISORY
Previous Volcano Alert Level: NORMAL

Current Aviation Color Code: YELLOW
Previous Aviation Color Code: GREEN

Issued: Wednesday, June 7, 2017, 3:03 PM AKDT
Source: Alaska Volcano Observatory
Location: N 55 deg 25 min W 161 deg 53 min
Elevation: 8261 ft (2518 m)
Area: Alaska Peninsula

Volcanic Activity Summary:
Over the past several days, there has been an increase in low-frequency earthquake activity at Pavlof. Such increases are sometimes seen prior to eruptive episodes, however in other cases they decline without eruptive activity. In addition, several short duration tremor-bursts have been observed today, and AVO received a pilot report of a possible ash cloud this afternoon. Infrasound data from local instruments on Pavlof and from a more distant network in Sand Point do not show any evidence of significant explosive activity. Precursory activity prior to eruptions of Pavlof are always very subtle, thus, on the basis of these observations we are increasing the Aviation Color Code to Yellow and the Alert Level to Advisory.

Recent Observations:
[Volcanic cloud height] 4000 ft. Pilot report of possible ash cloud.
[Other volcanic cloud information] Possible cloud not coming from vent, but drifting downwind.

 

Steam from the summit of Pavlof volcano. Images taken by Michael Levine, Commanding Officer of NOAA ship Oscar Dyson in Pavlof Bay, Feb. 13, 2017.

Remarks:
Pavlof Volcano is a snow- and ice-covered stratovolcano located on the southwestern end of the Alaska Peninsula about 953 km (592 mi) southwest of Anchorage. The volcano is about 7 km (4.4 mi) in diameter and has active vents on the north and east sides close to the summit. With over 40 historic eruptions, it is one of the most consistently active volcanoes in the Aleutian arc. Eruptive activity is generally characterized by sporadic Strombolian lava fountaining continuing for a several-month period. Ash plumes as high as 49,000 ft ASL have been generated by past eruptions of Pavlof, and during the March 2016 eruption, ash plumes as high as 40,000 feet above sea level were generated and the ash was tracked in satellite data as distant as eastern Canada. The nearest community, Cold Bay, is located 60 km (37 miles) to the southwest of Pavlof.

Source : AVO

Photo : Michael Levine

 

Villarica , Chile :

A total of 5773 seismic events, of which 5749 were classified as long-term earthquakes (LP), related to fluid dynamics in the volcano were recorded, with reduced displacement values (DRC) of less than 7.4 cm2. In addition, twenty-four (24) volcano-tectonic earthquakes (VT) associated with fracturing of rigid materials were noted. The higher-energy event had a local magnitude (M1) of M1.5 and was located 4.1 km south-east (SE) of the active crater at a depth of 3.5 km.
The intensity of the volcanic tremor (TR), a seismic signal associated with the fluid dynamics inside the volcano, showed average displaced values (DRC) of 2.2 cm2, which is considered low. The dominant frequencies were between 1 and 2.1 Hz for the period.

Infrasound sensors installed 4 km from the volcano crater recorded minor explosions associated with surface activity in the lava lake located inside the main crater. The maximum value calculated was 5 Pascals.
Images recorded with IP cameras installed near the volcano, when weather permitted, showed persistent low intensity degassing and low height, mainly white and glowing at night. The heights of the column do not exceed 250 m.
Based on data from five (5) GNSS stations controlling deformation of the volcano, small horizontal and vertical variations with small magnitudes and low velocities were observed. It should also be noted that the length of the control lines that pass through the volcano remains stable, based on the data provided by the two (2) inclinometers.
Data obtained from Nevados and Tralco stations , by  Optical Differential Absorption Spectroscopy (DOAS) equipment located 10 km northeast (NE) and 6 km southeast (SE) respectively of the active crater, recorded an average of sulfur dioxide (S02) emission value of 795 ± 37 td / day with a maximum value of 2857 t / day reported on 15 May. Consequently, an increase in S02 emissions is observed during this period, however, the average monthly base levels remain.

No anomalies have been recorded in emissions of sulfur dioxide (S02) in the volcano sector, according to information reported by the IMO (Ozone Monitoring Instrument) on its website http: // so2. Gsfc.nasa.gov / and NESDIS (National Environmental Satellite, Data and Information Service, http://satepsanone.nesdis.noaa.gov).

Thermal warnings were reported in the area associated with the volcano, the largest of which occurred on May 19 with a Volcanic Radiative Power (RVP) of 79 MW, which is considered moderate for this volcano.

Volcanic activity during the month remains stable, with variations in relation to changes in surface activity and the processes of degassing of the lava lake, which frequently alters its level. The deeper volcanic activity continues with recurrent volcano – tectonic activity of low amplitude.

The Villarica volcano remains at alert level: GREEN – active volcano with stable behavior.

 

Source : Sernageomin

Photos : Sernageomin (2015)

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