August 05 , 2016. EN. Nevados De Chillan , Tungurahua , Pavlof , Bárðarbunga.
August 05 , 2016.
Nevados De Chillan , Chile :
Activity bulletin of the Nevados de Chillán Volcanic Complex (16-31 July).
The level of activity of the volcanic complex is at: Yellow: changes in the behavior of the volcanic activity / probable date for an eruption weeks / months.
– There were seven hundred ninety-six (796) seismic events, among which twenty-nine (29) were related to rock fracturing process (named volcano-tectonic earthquakes (VT)), with a magnitude local (ML) of maximum M2.1 , associated with an event located 1.0 km west-northwest (WNW) of the active crater, 1.7 km deep. In addition, it was recorded seven hundred sixty seven earthquakes (767) associated with the fluid dynamics within the volcanic edifice, called long-period events (LP). The biggest LP type of earthquake has reached a local magnitude (ML) of 2.8 with a reduced displacement value (DRC) of 11.7 cm2.
– According to data obtained by the 4 GNSS stations that monitor the deformation of the volcanic complex, there are some low swings in the horizontal and vertical components of the stations, which do not exceed 0.25 cm / month. The control lines that cross the complex did not have rates higher than 0.45 cm / month. However, the data of the 2 two inclinometers installed around the complex show no trends related to internal deformation of the volcano, observing small amplitude variations.
– Sulfur dioxide (SO2) recorded by the station Chillan DOAS (Differential Optical Absorption Spectroscopy) located 3 km to the east-northeast (ENE) of the active crater has a mean value ± 715-836 t / d and a maximum of 1 961 t / d recorded on 25 July. The average flow is considered moderate for this volcano.
-The Images, obtained by the network of cameras in the area have sometimes shown a low pulsating surface activity, characterized mainly by emission of a whitish fumarole related to water vapor. On 21 , we noted an emission of ash and incandescent ballistic projectiles up to 300 m high. On 25, a few images obtained (due to weather) showed a deposition materials emitted from the crater with a range of about 300 m on the northeast side, though that one has not be seen directly. Over the following days, the occurrence of ash explosions due to the characteristics of the seismic signals is presumed, but weather conditions prevented the confirmation with surveillance cameras.
No abnormalities in sulfur dioxide emissions (SO2) into the atmosphere in the area near the volcanic edifice, according to data obtained by the group OMI (Ozone Monitoring Instrument) and NESDIS (National Environmental Satellite, Data, and Information service (http://satepsanone.nesdis.noaa.gov) were recorded.
No heat alerts in the area associated with the volcanic edifice, according to data released by the MODVOLC (Moderate Resolution Imaging Spectroradiometer) MODIS on its website (http://modis.higp.hawaii.edu/) and Mirova (Infrared Observation volcanic activity) on its website (http://www.mirovaweb.it/), the two surveillance systems indicate significant changes in the surface temperature of the earth.
The possible rise of a magma body of small volume and relatively deep (4-5 km) represented by seismic activity LP mentioned in the previous report have affected the surface hydrothermal system, generating phreatic explosions and / or phreato-magmatic with emission of low volumes of ashes. Although the process is still characterized by low energy, that suggests a new cycle of activity that causes the appearance of new phreatic explosions or phreato-magmatic eruptions of the active crater. This involves maintains the volcanic alert level to yellow, and as high hazard zone the area within a radius of 2 km around the active crater. Therefore, it is recommended to restrict access to the area.
Source : Sernageomin
Tungurahua , Ecuador :
SUMMARY OF THE ACTIVITIES OF THE VOLCANO.
The volcano is maintained with high eruptive activity.
Yesterday afternoon, a steam emission was observed with a low ash content. During the night, a light was observed in the crater with falling rocks on the southeast flank.
TECHNICAL AND OBSERVATIONS APPENDIX
The reference station has technical problems in the transmission of data, however, other signals shows that the activity is maintained.
Observations emissions and ashes:
Yesterday afternoon, the volcano has been discovered a time and a vapor emission with a low ash content heading towards the North was observed.
During the night, a light was observed in the crater with incandescent rocks falling to about 1,000 meters below the crater on the southeast flank.
Rain and lahars:
Some rainfall was recorded in the sector that have not generated lahars.
This report on a daily basis will be published at 12:00 (TL). In the case of an increase or a change in the behavior of the volcano, it will immediately issued a special report.
Source : IGEPN
Photo : José Luis Espinosa Naranjo ( 2012)
Pavlof , Alaska :
AVO/USGS Volcanic Activity Notice
Current Volcano Alert Level: ADVISORY
Previous Volcano Alert Level: WATCH
Current Aviation Color Code: YELLOW
Previous Aviation Color Code: ORANGE
Issued: Thursday, August 4, 2016, 11:21 AM AKDT
Source: Alaska Volcano Observatory
Location: N 55 deg 25 min W 161 deg 53 min
Elevation: 8261 ft (2518 m)
Area: Alaska Peninsula
Volcanic Activity Summary:
The eruptive activity that was observed intermittently since July 28 has ended or paused. Over the past several days there has been no evidence for continued ash emissions or signs of near surface magma in satellite data. As a result, AVO is lowering the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY.
Occasional views of the volcano in web camera images show small steam plumes at the summit. Seismic activity remains slightly above background levels. Satellite views have been obscured by clouds and intermittent partly clear views of the summit have showed only weakly elevated surface temperatures in one image on 2 August. At the present level of unrest, it is possible for activity to escalate rapidly and for ash emissions to recommence with only subtle precursory signals. AVO will continue to monitor the volcano closely.
View of Pavlof Volcano on 7/28/2016 at 13:00 Alaska time showing an ash and steam cloud drifting to the northeast. This photo was taken en route from Dutch Harbor to Anchorage from aboard PenAir aircraft.
Pavlof Volcano is a snow- and ice-covered stratovolcano located on the southwestern end of the Alaska Peninsula about 953 km (592 mi) southwest of Anchorage. The volcano is about 7 km (4.4 mi) in diameter and has active vents on the north and east sides close to the summit. With over 40 historic eruptions, it is one of the most consistently active volcanoes in the Aleutian arc. Eruptive activity is generally characterized by sporadic Strombolian lava fountaining continuing for a several-month period. Ash plumes as high as 49,000 ft ASL have been generated by past eruptions of Pavlof, and during the March 2016 eruption, ash plumes as high as 40,000 feet above sea level were generated and the ash was tracked in satellite data as distant as eastern Canada. The nearest community, Cold Bay, is located 60 km (37 miles) to the southwest of Pavlof.
Source : AVO
Photo : Izbekov, Pavel
Bárðarbunga, Iceland :
An earthquake of magnitude 4.0 hit the northern end of Bárðarbunga between 4 and 5 o’clock yesterday morning. The massive volcano, which lies under the Vatnajokull glacier, caused the eruption of 2014-2015 to Holuhraun in the highlands of northeastern Iceland.
Einar Hjörleifsson, specializing in natural hazards at the Met Office in Iceland, said that the earthquake is certainly important and among the strongest to have occurred since the volcano eruption in Holuhraun ended.
Yesterday, a 3.0 magnitude earthquake was measured as Bárðarbunga about noon, and a total of six earthquakes stronger than magnitude M2,0 were recorded throughout the day.
Einar explains that this is a continuation of seismic activity under the Bárðarbunga following the eruption of Holuhraun but there are no signs of increased volcanic activity. Specialists from Icelandic Met Office are monitoring the seismic activity in the area.
M4.0 August 3 Checked 4:15:17 p.m., 4.6 km NNE of Bárðarbunga
M3.0 August 3 12:48:08 Checked, 3.8 km NNW of Bárðarbunga
M2.9 August 3 Checked 4:29:39 p.m., the 3.9 km E of Bárðarbunga
Note: Yesterday, August 3, there was a seismic swarm under Bárðarbunga. At 16:15 an earthquake of magnitude M3,9, the largest of the swarm, was found on the north bank of the volcano caldera. This swarm is not considered out of the ordinary compared to the activity of Bárðarbunga in recent months, but nevertheless, the volcano is carefully controlled.
Overview of the week July 25-July 31
About 300 earthquakes were detected by the seismic network SIL of the Icelandic Meteorological Office. Most activities were at sea, north of Iceland. A little less activity took place in Mýrdalsjökull than the previous week. The strongest of the week was of magnitude M4,0 event on the crest Kolbeinsey
Source : icelandreview.com