February 18 , 2016. EN. Sakurajima , Copahue , Momotombo / Masaya / Telica , Zhupanovsky .
February 18 , 2016.
Sakurajima, Japan :
Morphological changes in the Showa crater of Sakurajima volcano since 2014, it was found an enlargement of 9 meters from east to west and 14 meters north-south. On the other hand, the ejecta, such as the ash deposited in and around the crater rose significantly from about 137 million cubic meters. In case of heavy rain, he was called to the attention of the people the strong possibility that debris flows occur. The wall separating the Showa crater of the Minamidake crater at the impact of the eruption, collapsed than two meters.
During 8-15 February JMA reported that 11 explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m. Based on JMA reports and satellite data, the Tokyo VAAC reported that during 10-12 February ash plumes rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted N, NW, W, S, and SE. On 14 February a pilot observed an ash plume that rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted S. The Alert Level remained at 3 (on a 5-level scale).
Sources : Sherine France /Kyt-tv , Ktstv. GVP.
Photo : M Rietze/ Le japon.fr
Copahue , Chile :
From 1 to 15 February 2016.
The level of activity of the volcano is at the level: YELLOW: changes in the behavior of the volcanic activity.
Time for a eruption: Weeks / month.
Based on the analysis of information obtained through the monitoring equipment and by observations of the volcano, the National Service of Geology and Mining (SERNAGEOMIN) – Volcanológico Observatorio de Los Andes del Sur (OVDAS) announces:
During this period were recorded twenty-eight (28) seismic events, fifteen (15) were classified as volcano tectonic (VT) associated with rock fracturing process.
Similarly, thirteen (13) events associated with the fluid dynamics inside the volcano, of which twelve (12) were identified as long-period earthquakes (LP) and one (1) very long event were recorded (VLPs).
As for the VT type of seismicity, the local magnitude (ML) were lower (M1.5). The most important energy event was located on the northeast side (NE), 1.5 km from El Agrio crater with a depth of about 4 km.
Lp type of events, showed reduced displacement values ( ) less than 8cm2, while local magnitude (ML) were below M1,7.
Seismicity of VLP types presented lower displacement values (DRC) maximum of 10cm2, mostly located around the crater.
During the month, there was a constant tremor signal, mainly associated with particulate emissions (gases and ash) from the crater El Agrio, which recorded values of RDC oscillating , typically less than 4cm2, values considered intermediate for this volcano. The dominant frequencies are concentrated in a frequency width of from 1.0 to 4.5 Hz.
According to data obtained from the four (4) GNSS stations, which seek to measure the deformation of the surface of the volcano, it is noted that the horizontal and vertical components have low amplitude oscillatory changes, similar to those recorded during the previous period. The highest rate of change of the horizontal components is 0.18 cm / month, while the greatest variation in the vertical component is 0.23 cm / month, which shows the general stagnation in inflation this month .
Sulfur dioxide emissions (SO2) recorded by the DOAS equipment (optical absorption spectrometry differential) of the Triplets station, located 5 km to the east–northeast (ENE) of the active crater, presented a mean value of 753 ± 199 t / day and a maximum value observed during the first fortnight of 2735 t / day, recorded on February 13. The average flow is considered at low levels for this volcano.
IP cameras installed near the volcano recorded constant emissions of materials from the active crater El Agrio, accompanied by incandescence. These emissions are mostly characterized by a grayish color showing the presence of particulate matter.
Source : Sernageomin
Photos : los Andes .com , Carlos Di Nallo .
Momotombo / Masaya / Telica , Nicaragua :
In the last 24 hours, 02 gas explosions with emission of ash and incandescent material, accompanied by volcanic tremors were recorded. The first explosion took place at 3:44, and was the biggest, emitting a glowing materials column of 800 meters above the crater.
The explosions on the Momotombo that took place over the last 5 days have produced little or very small seismic signals, suggesting that the volcanic conduit opposes only a little resistance to the rise of volcanic material, which decreases the violence of explosions and increases the probability of a lava flow.
The micro-seismic activity of the volcano continues, linked to the movement of fluids beneath the volcano.
Seismic amplitude in real time (RSAM) is at low and moderate levels between 180 and 60 units.
The lava lake is visible on the floor of the crater Santiago.
The RSAM values are at elevated levels, from 400 to 1,100 units, and are produced by strong magma movement.
Currently, the volcanic gas emission is low, and the possibility of explosions which eject large amount of gas, fragments of incandescent rock and even lava persists .
The Telica continues to show micro-seismic activity, movement mainly associated with volcanic fluids and to a lesser extent, small gas explosions.
A slight increase in the volcanic tremor at 2:00 today is recorded.
The possibility of emergence of new gas explosions, with expulsion of volcanic ash and incandescent rocks fragments of different sizes is maintained.
It is recommended to tourists and people not to approach the volcano’s crater.
Source : INETER.
Photos : elestimulo.com, orgullodemipais.com , nuevaya.com.
Zhupanovsky , Kamchatka :
Elevation 2899 m
KVERT reported that moderate steam-and-gas activity at Zhupanovsky continued during 5-12 February. Explosions on 5, 7, and 9 February generated ash plumes detected in satellite images that drifted over 545 km E and N. A thermal anomaly was detected during 5 and 9-11 February. An explosion at 0929 on 13 February was recorded by a video camera and generated an ash plume that rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted E.
A larger explosion visually observed a minute later generated an ash plume that rose to an altitude of 10 km (32,800 ft) a.s.l. and drifted 50 km SE. The Aviation Color Code was raised to Red. In a report issued at 1134, KVERT noted that only moderate amounts of gas and steam rose from the volcano; the Aviation Color Code was lowered to Orange. Ash from the earlier explosions drifted E over Kronotsky Bay and NW. A few hours later an ash plume was detected in satellite images rising 1 km above the volcano and drifting 288 km E.
Sources: Kamchatkan éruption volcanique Response Team (KVERT) , GVP
Photo : S. Samoilenko, IVS FEB RAS ( 2013 )