14/04/2015. Etna, Tungurahua, Reventador .
Etna, Sicile :
After a quiet period that lasted more than two months, Etna shows new signs of life. At 1:05 p.m. UTC (local time = -2) April 12, 2015, began a short explosive sequence in the western part of the crater to the Bocca Nuova, the largest of the summit craters of Etna. Within three minute period took place two explosive events that generated puffs of ash, clearly visible thanks to the excellent weather and no wind at altitude.
Ash puffs s’ rose from a few hundred meters above the summit of the volcano before dispersing. The two explosions generated a little more energy than the events recorded in the last days by the seismic monitoring network of the INGV-Osservatorio Etneo. After this, there was no more ash emissions.
Source : INGV
Photo : Gio Giusa
Tungurahua, Equateur :
In the afternoon of 09/04/2015, the clouds dissipated is around the volcano and we could see a small white vapor emission, very different activity from that of April 8, 2015, which was characterized by tremor continuous and moderate load ash emissions .No strange noises or ash fall reported by sentinels, except for Chogluntus sector where until now occurs a black ash fall, which is associated with a column of 600 meters above the crater.
Yesterday at 8:21 p.m. and 10:43 p.m. (local time) occurred two major earthquakes, type LP located at a depth of 6 km below the summit. Later today, at 0:14 (TL) started a small swarm of events LP, which looks like a “drum roll”, recorded mainly in the RETU station (4000 m), on the north side. The events show frequencies between 1 and 5 Hz. The number of tremors was 1.7 per minute. Between the beginning of this sequence of events until today at 13:05 there were 1360 LP events. These LP events are mainly located between 1 and 3 km deep beneath the crater with a tendency to rise.
From 0:14 (TL), when we starts to record a swarm of events long period (LP) until 13:05 were processed and cataloged a total of 1360 LP events.
It is emphasized that these can be related to the rise of new magma.
During the 16 years since the beginning of the eruption of the Tungurahua volcano, there never had this kind of seismic events, as in other volcanoes like Mount St. Helens in the United States, called “drums “and are interpreted as associated with emissions of highly viscous magma. By presence of new magma in the depths and the amount of gas , this could generate a large explosions.
The flow of SO2 measured on the Tungurahua Volcano remains at high levels on average baseline of 1,300 t / day from 1 April 2015. The daily number of valid measures also increased, indicating that the degassing s’ is continued for the time. These values, however, are unable to those recorded in previous periods of eruptive activity that generally exceed 2,000 t / day. Value for April 10 include only the data until 12:00 TL.
Inflation of the inclinometer Retu continues at a rate of 20 urad / day in the radial axis, which means that there are internal pressures which are at the origin of a stress below the top of cone.
Source : IGEPN
Photo : IGEPN , José Luis Espinosa Naranjo ( 19 sept 2014 )
Reventador, Equateur :
SUMMARY OF ACTIVITY OF THE VOLCANO.
The volcano has a moderate activity. The volcano remained covered so that there was no surface observations.
COMMENTS AND TECHNICAL APPENDIX.
Seismicity: 11 explosions, 18 long-period events (LP), 14 episodes of tremor emissions and 9 episodes of harmonic tremor were recorded.
Observations: The volcano remained cloudy most of the time so it was not possible to have a direct observation of the crater.
Thunderstorms and lahars: No rain and lahars were reported in the area.
Source : IGEPN
Photo : Geographic.org