April 07 , 2017. EN. Banda Api , Copahue , Poas , Etna .
April 07 , 2017.
Banda Api, Indonesia :
Visual observations during the period from 28 March to 5 April 2017 did not show any significant change in color or height of the emission column.
The increase in seismicity following the volcanic earthquake in Terasa on April 4, 2017 indicates a process of rock fracturing due to magma movements (gas, liquid and solid rock). On the importance of the seismicity recorded during the period 2 to 4 April 2017, this suggests that this process takes place with sufficient energy to induce the possibility of an eruption but this can not be established.
Looking at the number of occurrences of volcanic earthquakes since 1 January 2017 we see that the trend has oscillated to the increase since the beginning of March 2017. At the end of the period there was an increase in the number of Volcanic earthquakes. Similarly, the seismic amplitude graph showed the same pattern. This may indicate the supply of magma from the depths to the surface.
The frequency chart of the dominant earthquakes shows that seismicity is dominated by high frequency (5-10 Hz) earthquakes, from early March 2017 to the end of the observation period and are associated with the incidence of deep volcanic earthquakes. The intensity of seismicity in this frequency range has increased significantly over the last 3 days.
Seismic monitoring stations record seismic events around the Banda Api, with a frequency that during the last 3 days is identical to before the eruption of Banda Api in May 1988.
In addition to tectonic activity, seismic events can also indicate the release of stress on structures around the volcano induced by deep magma movements.
Although the eruption is not certain, it is necessary to increase the intensity and quality of G. Banda Api surveillance as well as increase public awareness of preventive measures.
Based on the results of the monitoring of the seismic and visual analysis, G. Banda Api’s activity levels have gone from level I (normal) to level II (Alert) as of 5 April 2017 14:00.
If there is a significant change in the volcanic activity of G. Banda Api, the level of activity can be lowered / high depending on the level of activity and threats
The Indonesian Civil Protection said it mapped the area and concluded that more than 770 people live within 1 km of the volcano. All should be moved as soon as possible.
The visual observations showed no significant change in the clouds of gases emitted by the volcano, but the seismicity indicates a fracturing process due to the ascent of the magma and the number of events recorded between the 2 and the 4 April suggests that this process is large enough to produce a rash. There may be no eruptions, but the seismicity observed in recent days is identical to that preceeding the 1988 eruption.
Source : VSI. Lave ( C Granpey)
Photo : Banda-Api-09.05.1988 I.-Yoshida-VSI
Copahue , Chile:
During the recorded period, forty-one (41) seismic events of which thirty-eight (38) were classified as volcano-tectonic (VT), associated with fracturing processes of rigid materials were recorded. Similarly, three (3) events that were identified as very long earthquakes (VLPs) were recorded.
With regard to the seismic activity of the VT type, the local magnitudes (ML) are less than or equal to M2,4. The highest energy event was located north-northwest (NNO), 4.8 km from the El Agrio crater, with a depth of 1.6 km.
For VLP events, these showed reduced displacement values (DRC) of less than 3 cm2.
Throughout the period, a very low amplitude constant tremor signal was recorded, associated mainly with gas emissions from the El Agrio crater but to a lesser extent than in previous months. This signal showed DRC values oscillating about 0.4 cm 2. The dominant frequencies were concentrated over a bandwidth ranging from 1.2 to 2.1 Hz.
From the data obtained from four GNSS stations measuring the deformation of the volcano surface, small amplitude displacements were observed, the highest rate not exceeding 0.3 cm / month in the horizontal components and 0.4 cm / Month in the vertical components. The lines of control across the crater were also stable.
Emissions of sulfur dioxide (S02) recorded by the Triplets (Differential Spectrometric Absorption – DOAS) equipment located 5 km east-northeast (ENE) of the active crater had an average value of 334 ± 197 t / day and a daily maximum of 637 t / day, reported on 19 March. SO2 emission levels are at the baseline level for this volcano.
The IP cameras installed in the vicinity of the volcano showed a constant degassing of the active crater (El Agrio), predominantly whitish in color, associated with the hydrothermal system, with incandescence overnight. The highest emission column was recorded on 22 March, with a height of about 700 m.
No anomalies in emissions of sulfur dioxide (SO2) into the atmosphere in the volcano sector have been reported, according to data published by the Ozone Monitoring Group (SMI). Sulfur dioxide group Http://so2.gsfc.nasa.gov/) and the National Satellite Data and Information Service (NESDIS) (http://satepsanoine.nesdis.noaa.gov).
No thermal alerts were reported in the area associated with the volcano according to infrared, volcanic activity observation (Mirova) (http://www.mirovaweb.it/) and (MODVOLC) data ( Http://modis.higp.hawaii.edu/).
The Copahue volcano continues at: YELLOW LEVEL: changes in the behavior of volcanic activity – time for a possible eruption: weeks / months.
Note: It is recommended to apply preventive restrictions on the access of an area near the crater with a radius of 1.5 km.
Source : Sernageomin
Photos : Archives
Poas , Costa Rica :
The Poas Acting Up Again .
4 APRIL 2017. After several months of relative calm, the Poas Volcano is acting up again, with a small groundwater and ash discharge.
Volcanologists Gino González and Yemerith Alpízar of Volcanes Sin Fronteras (Volcanos Without Borders) visited the colossus over the weekend and reported the reactivation after the volcano had remained relatively calm for eight months. A similar activity was recorded in 2013.
Specialists say theywere in the southwestern sector of the colossal crater where they found that the lagoon increased its temperature by 3 degrees Celsius compared to last month. The lagoon temperature is now 38 Celsius (100 Fahrenheit).
They also found that the lake has a gray color with sulfur floating in several sectors, with very acidic gases that forced the use of special masks. For now there is no presence of magma.
The ash from Poas is quite different from the ash spewed by the Turrialba, whose ash emanations are not acidic.
The Poas, located in the province of Alajuela, a stone’s throw if you will, from the San Jose airport, has a phreatic activity, which is water and hot gases, without direct magma. This is in contrast to the Cartago volcano, the Turrialba.
Will the Poas behave like the Turrialba? For now, experts say the colossi have a distinc activity.
Experts says they will continue with constant monitoring of the Poas, a major tourist destination in the Central Valley and that visitors should not be surprised if they feel the gases and the strong smell, which can mean shorter times in the lookout point.
Poas national park officials, where the volcano is located, also call on visitors to not use unauthorized trails – such as access by the Bajo del Toro – located on the west wall of the volcano, where the increased activity has occurred.
“It’s a dangerous, very fractured road – this weekend’s eruption – spewed ash and can affect those who walk there, the recommendation is that they better not do it,” Gonzalez said.
Source : Q COSTA RICA
Photo : jejecece.over-blog.com
Etna , Sicily :
INGV Update, ETNA Activity from 17 March to 6 April 2017
The eruptive episode that began on the morning of March 15, 2017 for Etna’s Southeast Crater (SEC) continued for a few days with strombolian activity and ash emissions (see photo at left, taken at bedtime On the southern side of the volcano, by Boris Behncke, INGV-OE) from the mouth on the old « saddle » between the old and the new SEC cone. Ash emissions increased on the evening of 16 March, alternating with ash-free strombol activity, causing low ash falls on the southeast, south and southwest slopes of the volcano. On the morning of 18 March the explosive activity decreased sharply and until the evening of the 19th only sporadic strombolian explosions occurred, which significantly decreased in the following night. Since then, there have been some sporadic and weak ash emissions either from the mouth of the « saddle » or from the vent located on the top of the eastern flank of the cone of the new SEC.
The continuous emission of lava flows continued from the effusive mouth, which began on the evening of 15 March at an altitude of 3010 m at the southern base of the SEC. In the early days, a lava flow first developed in a southeasterly direction towards the west of the Valle del Bove, where two small lava flows formed on the downstream wall Reaches about half the height of the wall. The main lava arm, on the other hand, moved south along the edge of the Valle del Bove to overflow the west wall to the east of the « Cisternazza » crater and form a long lava arm of a few hundred meters. In the afternoon, a more fed lava arm poured beside the previous one on the wall, which here has a steeper slope, causing active lava fronts to slide, especially when it has covered areas filled with snow.
During the afternoon of March 18th, there was the almost continuous collapse of the lava flow on the wall of the Valle del Bove, the most important at 15: 00-15: 15 UTC (local time = -1) and 17: 50-18: 05, during which several avalanches of incandescent material reached the base of the wall. The presence of abundant steam in the ash plumes generated by these events indicates a strong interaction with snow on the ground (see left center image, retrieval of the visual surveillance camera from Catania). The collapse phenomena decreased during the following night, and the casting was widened at the base of the wall on the flat earth of the Valle del Bove. The lava flow to the Valle del Bove decreased sharply during the day of 20 March and totally ceased the following day; Upstream, in the area between Torre del Filosofo and the station « Belvedere » on the Valle del Bove, for a few days, were still fed a few small lava flows. On 21 March a new well-fed lava flow began to stretch along the western slope of the 2002-2003 cone and pour into the saddle between the cone and the neighboring cone of Monte Frumento Supino.
I don’t know whether you noted this, but we have yet another « puttusiddu » (little hole) that opened a few days ago on the south flank of the « saddle cone » of Etna’s Southeast Crater (source of the latest two eruptive episodes of 27 February – 1 March and 15-20 March 2017). Here is how it appeared when seen from home at sunrise on 1 April 2017.
This lava flow has gradually spread south-south-west; A slope of Monte Frumento Supino, diverted it towards the Southwest, towards the lava fields of 2002-2003. By the end of March, the front had reached an altitude of about 2300 m where it stopped; In early April several lava arms developed next to the initial stop, more or less at the same level.
The almost daily inspections carried out by INGV-Osservatorio Etneo staff revealed that, on its way, the lava flow has « channeled » (see photo below on the left, taken on the evening of April 1, By Emanuela De Beni and Stefano Branca, INGV-OE). Currently (early afternoon of April 6, 2017), effusive activity continues without significant change; Just as the same phenomenon has occurred over the past two weeks in the average amplitude of volcanic tremors.
During the explosive activity of mid-March, the new pyroclastic cone formed around the mouth of the « saddle », did not appear to have increased in height, but was considerably expanded. In the last days of March (probably around the 28th) a small « pit crater » (crater well) was opened on the south side of this cone, which in the hours of the night shows a strong glow. In addition, throughout the period covered by this report, the intense glow of the venting opening that opened on 7 August 2016 on the northeastern edge of the Voragine was also visible to the eye naked.
Source : INGV
Photos : B Behncke