September 11 , 2019.

Colombia , Chiles / Cerro Negro :

Weekly activity bulletin of Chiles and Cerro Negro volcanoes
The activity level of the volcanoes continues at the level: YELLOW LEVEL ■ (III): CHANGES IN THE BEHAVIOR OF THE VOLCANIC ACTIVITY.

Following the activities of VOLCANOES CHILES AND CERRO NEGRO, the COLOMBIAN GEOLOGICAL SERVICE (SGC) reports that:

For the period from September 3 to 9, 2019, seismic activity in the Chile-Cerro Negro volcanoes region continued to show similarities in seismic numbers and energy compared to previous weeks, totaling about 757 events for the week evaluated. . Predominant seismicity is always associated with the fracturing of rock materials in the volcanic building.

The earthquakes were located mainly south of the volcanic complex and mainly at epicentral distances less than 7 km from the Chiles volcano, at depths up to 9 km (below the summit) and at a maximum local magnitude of 2.5 on the Richter scale. No recorded earthquakes were felt by residents of the Chiles – Cerro Negro volcanic complex.

Other geophysical and geochemical parameters of volcanic monitoring did not show significant variations.

The Colombian Geological Service and the Institute of Geophysics of the National Polytechnic School of Ecuador are attentive to the evolution of the volcanic phenomenon and inform in a timely manner the observed changes.

Source : SGC.

Photo : SGC.

Italy / Sicily , Etna :

Apparently, the tremor has fallen sharply. No communication from INGV yet.

There was a big activity tonight.

Source : INGV.

Photo : Gio Giusa .

Indonesia , Ibu :

Level of activity at Level II (WASPADA). G. Ibu (1340 m) has been erupting continuously since 2008.

Since yesterday and until this morning, the volcano was clearly visible until it was covered by fog. The smoke from the crater is observed at a height of 200 to 800 meters above the summit of the peak, the pressure being low to moderate, its white-gray color. It moves towards the south and the east with a weak intensity, moderate and thick.

The seismographs dated September 10, 2019, recorded:
77 eruption earthquakes
72 earthquakes of explosion
46 harmonic tremors.

https://www.facebook.com/toguualamo/videos/2541924179161206/

Recommendation:
Communities around G. Ibu and visitors / tourists should not move, climb or approach within 2 km with sector expansion 3.5 km from the opening in the northern part of the active crater of the G Ibu.

VONA:
The last VONA code was sent with the color code ORANGE, published on September 4, 2019 at 9:36 am, which corresponded to an eruption with an ash column height of about 1625 meters or about 300 meters above the summit. The column of ashes was moving south.

Source : PVMBG.

Video : Alex Djangu Trekker.

Alaska , Semisopochnoi : 

51°55’44 » N 179°35’52 » E,
Summit Elevation 2625 ft (800 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Low-level eruptive activity may be continuing at Semisopochnoi. Seismic activity over the past day remains elevated with low-frequency earthquakes but there were no explosions detected in regional infrasound data. Satellite observations were mostly obscured by clouds over the past day.

Semisopochnoi is monitored with an on-island seismic network and remotely by satellite and lightning sensors. An infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a slight delay (approximately 13 minutes) if atmospheric conditions permit.

Source : AVO.

Photo : Kim F.