April 23 , 2017. EN. Poas , Mauna Loa , Kilauea , Copahue .

Home / blog georges Vitton / April 23 , 2017. EN. Poas , Mauna Loa , Kilauea , Copahue .

April 23 , 2017. EN. Poas , Mauna Loa , Kilauea , Copahue .

April 23 , 2017.

 

Poas , Costa Rica :

Activity report of the Poas Volcano, 22 April 2017, updated at 10.30 am.

Over the past 24 hours, the Poas has shown strong degassing with a plume loaded with gases, aerosols and ash, this activity being associated with a low to moderate volcanic variable volcanic amplitude, with addition of eruptions Which occur constantly accompanied by ejections and falls of pyroclastic materials (very hot rocks) which fall near the crater. In the early morning of April 21 there was recorded a continuous tremor of moderate amplitude, which at about 10:50 am even decreased for about 3 ½ hours, then again increase in amplitude and keep almost constant.

 

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

An eruption was recorded around 6 pm with a column rising 200 above the crater. From 7:00 to 20:45 there was recorded a seismic signal showing discrete events, closely followed, which are different from the tremor observed in the early hours of the morning and part of the afternoon of April 21. The tremor began to decline at 21:00 yesterday and since 02:00 the Poas volcano shows a drop of tremor, showing low amplitude. Sporadic VT seismic events are also recorded. On April 22, Poas Volcano is quieter with a new incandescent mouth in the active crater. A plume of ash richer in the early hours of the day heading southwest is observed. According to the reports of the park guards and the population around the volcano there are great noises and rumblings emitted that can be heard and felt at 3 km from the ranger station of the park and also from Bajos del Toro. The amplitude of the signal has slightly increased since 06:00 and remains equal until the report is presented.

It is officially reported by the Grecia Red Cross of ash falls in the areas of San Miguel, Carbonal, Cajon, San Francisco, San Roque and San Juan Norte de Poas.

 

Source : Ovsicori

 

Mauna Loa , Hawaï :

19°28’30 » N 155°36’29 » W,
Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

Activity Summary:
Mauna Loa Volcano is not erupting. Rates of deformation and seismicity remain above long-term background levels.

 

 

Observations:
Mauna Loa is not erupting. During the past week, small-magnitude earthquakes were recorded primarily beneath the upper west flank of the volcano, with most at depths of 5-13 km (3-8 mi). GPS measurements continue to show deformation related to inflation of a magma reservoir beneath the summit and upper Southwest Rift Zone. No significant changes in volcanic gas emissions were measured.

Source : HVO

 

Kilauea , Hawaï :

19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary:
Kīlauea Volcano continues to erupt at the summit and at Puʻu ʻŌʻō on the East Rift Zone. The episode 61g lava flow continues to enter the ocean at Kamokuna, where a small lava delta has been growing since late March. Surface flows remain active above the pali near Puʻu ʻŌʻō. These flows pose no threat to nearby communities. At the summit, the lava lake level did not change appreciably since yesterday; it is still about 21 m (70 ft) below the floor of Halemaʻumaʻu Crater this morning.

 

Summit Observations:
Tiltmeters at Kīlauea’s summit recorded very little change in tilt over the past day. The lava lake level did not change much since it was measured at about 21 m (70 ft) below the floor of Halemaʻumaʻu Crater yesterday morning. There was no change in the levels of seismicity at the summit. Tremor amplitude continued to fluctuate with the vigor of lava lake spattering. Summit sulfur dioxide emission rates remained high.

Puʻu ʻŌʻō Observations:
Webcam images over the past 24 hours showed persistent glow at long-term sources within the Puʻu ʻŌʻō crater and from a small lava pond on the west side of the crater. Seismicity was steady over the past 24 hours. A tiltmeter on Puʻu ʻŌʻō cone recorded slight deflationary tilt over the past day. The sulfur dioxide emission rate from all East Rift Zone vents remained elevated but significantly lower than the summit emission rate.

 

Lava Flow Observations:
The episode 61g flow was still active, entering the ocean, and slowly building a lava delta at Kamokuna. No active surface flows were observed in webcam views on the coastal plain yesterday, but surface flows remained active on the upper portion of the 61g flow field above the pali, posing no threat to nearby communities at this time.

Source : HVO

Photos : Bruce Omori , David Ford.

 

Copahue , Chile :

During this period of thirty seismic events, all classified as volcano – tectonics (VT) associated with fracturing processes of rocks were recorded. The amplitude of the continuous tremor signal has decreased at background level.
With regard to the seismic activity of the VT type, the local magnitudes (ML) are less than or equal to M1,3. The highest energy event was located east-northeast (ENE), 10.8 km from the El Agrio crater with a depth of 4.8 km.
From the data obtained from four (4) GNSS stations measuring the deformation of the volcano surface, the observed displacements were of low magnitude, the highest rate not exceeding 0.3 cm / month in the horizontal components and 0 , 4 cm / month in the vertical. In turn, the command lines that cross the crater were also stable.


Sulfur dioxide emissions (S02) recorded by the differential absorption spectrometry equipment (DOAS) of the Mellizas station, a 5 km east-northeast (NE) of the active crater, had an average value For the period of 731 ± 554 t / day and a daily maximum of 1952 t / day, reported on April 5th emissions. S02 emissions are at baseline levels for this volcano.

The IP cameras installed near the volcano showed a constant degassing from the active (El Agrio) crater, predominantly whitish, associated with the hydrothermal system, with sporadic incandescence overnight. The largest column was recorded on April 8, with a height of about 580 m.
No emissions of sulfur dioxide (SO2) into the atmosphere in the volcano sector have been reported, according to data published by the Ozone Monitoring Instrument (IMO) Sulfur dioxide group (http: / / /so2.gsfc.nasa.gov/) and NESDIS, (http://satepsanoine.nesdis.noaa.gov).
No thermal alerts were reported in the area associated with the volcano according to the infrared data on the Mirova site (http://www.mirovaweb.it/) and MODVOLC (http://modis.higp.hawaii.edu /).

 

Monitoring parameters indicate a decrease in volcanic activity at its baseline level, keeping only one activity related to the heat-excited hydrothermal system of an underlying magma body under cooling. This level has never been seen since before the eruption of December 2012.

It is considered that the volcanic system is in equilibrium, so the level of technical alert is changed:
GREEN LEVEL: Active volcano with stable behavior – There is no immediate risk – Possible time for an eruption: months / years.
Note: It is recommended to apply preventive restrictions on the access of a zone near the crater with a radius of 500 meters, taking into account the activity of fumaroles that persists.

Source : Sernageomin

Photos : Archives

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