February 19, 2016. EN. Pacaya , Nevados de Chillan , Kilauea , Asosan .
February 19, 2016.
Pacaya , Guatemala :
Type of activity : Strombolian
Morphology : composite Stratovolcano
Geographical location: 14 ° 22′ 50 » N Latitude , 90 ° 36′ 00 » West Longitude.
Altitude: 2552 m
Activity: Currently, his activity is observed with emission of white fumaroles, accompanied by émissions of gas mostly blue color, at low altitude, which are dispersed at low altitude towards the south.
The National Institute of Seismology, Volcanology, Meteorology and Hydrology (INSIVUMEH) has indicated that the Pacaya volcano increased its gas explosions and expulsions that can cause harm to visitors.
The Pacaya volcano expels bluish gas at low altitudes that are scattered south and a continuous emission of white fumaroles.
Therefore, INSIVUMEH recommends to the Pacaya National Park to restrict access to the crater because of the volcano, which has small explosions and ejected volcanic materials that could cause harm to people who are in the vicinity .
Sources : Insivumeh , Soy502.
Photo : Jose Antonio Cabo Buján
Nevados De Chillan , Chile :
The level of activity of the volcanic complex of Nevados de Chillán is at level : YELLOW: changes in the behavior of the volcanic activity. Time for an eruption: Weeks / month.
Based on the analysis of information obtained from monitoring equipment and surveillance of the volcanic complex, the National Service of Geology and Mining (SERNAGEOMIN) through the Volcanological Observatory of Southern Andes (OVDAS) communicates :
It was recorded nine hundred and twenty four (924) seismic events, including:
Sixty-three (63) were associated with the fracturing process of rigid materials (called volcano-tectonic earthquakes, VT) with a maximum local magnitude (ML) of M3.2. It was ranked 858 earthquakes associated with fluid dynamics inside the volcano (called long-period events, LP) with maximum local magnitude (ML) of M2,8 and a reduced displacement value (RDC) less than 75cm2.
Finally, during this period, three (3) Tornillos type of events were recorded (TO), processes involving resonance in volcanic conduits with magnitudes equal or below 1.4 and reduced displacement values (DRC ) less than 1cm2.
During the period analyzed, it was also noted 175 episodes of discrete tremor, signal associated with the fluid dynamics inside volcanic conduits, and the emission of particulate matter to the surface (explosions), which were recorded by IP cameras installed in the volcano area. These tremor episodes had reduced displacement values (DRC) of less than 30 cm2, values considered to be high.
The images obtained by the camera network installed in the region, showed surface activity, especially characterized by the appearance of occasional explosions from issuing centers near the the crater Arrau and the « New » crater as was observed during the last flyby.
The data provided by two (2) electronic inclinometers and five stations (5) GNSS that monitor the deformation of the volcanic complex, showed no change due to the internal activity of the volcano during this period.
Sulphur dioxide (SO2) recorded on the Nevados de Chillan volcanic complex by the team DOAS (differential optical absorption spectrometry) of Chillán Station , installed 3 km to the North East (NE) of the active crater showed a mean value of 2051 ± 279 t / day and a maximum value observed during the first two weeks, with 3113 t / day, registered on 13 February, seen as an intermediate value.
In collaboration with the ONEMI of the Bío Bío region, a survey was held on February 11, which has managed to identify a third crater, at a location that suggests a linear trend of about 150 m in total length from the two other craters on a North-east axis (NNE). A decrease of activity of fumaroles is also highlighted, consistent with a drop in temperature of these ones (about 50 ° C lower) compared to the overflight conducted on January 30. The lowest temperature (125 ° C) indicates a decrease in the heat transfer from the magma to the hydrothermal system, which increases the proportion of the water vapor in the degassing process.
The images published by the OMI Group (The Ozone Monitoring Instrument), Sulfur Dioxide Group (http://so2.gsfc.nasa.gov/) and NESDIS (National Environmental Satellite, data and information (http // satepsanone. Nesdis.noaa .gov) not report any anomaly in the sulfur dioxide (SO2) into the atmosphere in the volcanic complex sector.
Thermal radiation released by the MODVOLC (Moderate Resolution Imaging Spectroradiometer) MODIS on its website (http://modis.higp.hawaii.edu/) and Mirova (Middle InfraRed Observation of volcanic activity) on its website (http: / /www.mirovaweb.it/), surveillance systems that indicate major changes in surface temperature, reported no thermal alerts in the area associated with the volcanic complex.
Monitoring parameters during the last 15 days showed a trend suggesting the release of the pressure on the the hydrothermal system near the surface of the active cone may be related to a decrease in heat flow from the underlying magma, characterized by lower explosive events and ash emissions in recent days. However the levels of sulfur dioxide flows and the recording of seismic events VT type suggest movement in depth of new masses of igneous materials. This implies the emergence of new impulses for surface activity with the possibility of generating phreatic explosions equal and / or greater than those recorded so far, and with phreatomagmatic eruptions or an evolution towards a purely magmatic stage represented by lava effusions from the currently active craters.
Therefore, the level of volcanic alert level remains at YELLOW, focusing on areas considered as high risk, including an area of 2 km around the active craters. It is recommended to limit access to this area.
Source : Sernageomin.
Photos : Sernageomin, Patricio Arias .
Kilauea , Hawai :
19°25’16 » N 155°17’13 » W,
Summit Elevation 4091 ft (1247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Kilauea Volcano continues to erupt at its summit and from its East Rift Zone. The summit is currently experiencing deflationary tilt consistent with the beginning of a DI event. Overall seismicity and deformation rates are within normal range. Scattered surface flows persist in the ‘June 27th’ flow field; all within 6 km (4 mi) of Pu’u ‘O’o.
The lava lake within the Halema’uma’u Overlook crater continues to be active. For most of the past 24 hours it had a height of about 29 m (95 ft) below the rim of the Overlook crater. At 2:00 AM HST, the level began to drop and as of 8:30 AM HST is at 33 m (108 ft) below the crater rim. The change in lava lake level coincided with a change from minor inflationary to deflationary tilt, consistent with the beginning of a summit DI event (see link below for definition). Rates of seismicity remain low with periods of tremor associated with spattering within the Overlook vent. When last measured by vehicle in late January, the summit sulfur dioxide emission rate averaged 5,300 metric tons/day.
Pu’u ‘O’o Observations:
Thermal webcam images show no significant changes in Pu’u ‘O’o crater; persistent glow continues at long-term sources. Only minor inflationary tilt was recorded on a nearby tiltmeter and the seismicity rate remains at background level. The sulfur dioxide emission rate from all East Rift Zone vents was about 345 metric tons/day when it was last measured on February 2, 2016.
A closer view of the lava lake surface. The white plume originates from lava spattering, just out of view.
June 27th Lava Flow Observations:
Webcams continue to show scattered surface flow activity on the June 27th flow field, although rain and fog hamper visibility. All active flows are within 6 km (4 mi) northeast of Pu’u ‘O’o and do not currently threaten any nearby communities.
Source : HVO.
Photos : Bruce Omori, HVO.
Asosan, Japan :
The Asosan, a volcano on the Japanese island of Kyushu, on alert level 2 from 11/24/2015 experienced an eruption this February 18 to 4:59 p.m. loc., Accompanied by a light colored plume. It was reported by the Tokyo VAAC on the basis of information of Himawari-8 satellite, at 8:05 UTC.
The 24-km-wide Asosan caldera was formed during four major explosive eruptions from 300,000 to 90,000 years ago. These produced voluminous pyroclastic flows that covered much of Kyushu. The last of these, the Aso-4 eruption, produced more than 600 cu km of airfall tephra and pyroclastic-flow deposits. A group of 17 central cones was constructed in the middle of the caldera, one of which, Nakadake, is one of Japan’s most active volcanoes. It was the location of Japan’s first documented historical eruption in 553 AD. The Nakadake complex has remained active throughout the Holocene. Several other cones have been active during the Holocene, including the Kometsuka scoria cone as recently as about 210 CE. Historical eruptions have largely consisted of basaltic to basaltic-andesite ash emission with periodic strombolian and phreatomagmatic activity. The summit crater of Nakadake is accessible by toll road and cable car, and is one of Kyushu’s most popular tourist destinations.
Sources : B Duick , GVP.