October 07 , 2017.
Agung , Indonesia :
Recent Updates on Mount Agung Volcanic Activity (5 October 2017 17:00 Central Indonesia Time/CIT UTC+8).
The rate of volcanic earthquakes in the last 12 days has not accelerated but continues to fluctuate at high levels. In average, there are still 1-3 earthquakes per minute with the total number reaching greater than 600 per day.
Shallow volcanic earthquakes from September 24 to October 5, 2017 have increased in number (generally more than 200 earthquakes per day) when compared with the previous period (generally less than 200 earthquakes per day). This may indicate that magmatic activity at shallow depths is still high.
The largest earthquake to be recorded during this crisis is a M4.3 (27 September 2017 13:12 Central Indonesia Time/CIT UTC+8). It was felt in the local area with an intensity of MMI III-IV (Modified Mercalli Intensity). Most of the largest recorded earthquakes have a magnitude between M2.0-M3.0. The number of felt earthquakes at the Mt. Agung Volcano Observatory in Rendang village (AVO Rendang) (around 12.5 km to the South-Southwest of the volcano) reached a maximum on September 27, 2017 with 14 events. After that, the number of earthquakes felt at the AVO Rendang has decreased.
Earthquakes are located under Mt. Agung with a range in depths up to 20km below the summit.
Real Time Seismic Amplitude (RSAM) in the last 12 days has not increased but remains at a high level.
Earthquake activity is still dominated by high frequency events. This indicates that seismic activity at the volcano still represents the brittle failure of rock inside the volcano in response to magmatic intrusion.
Changes in seismic velocity indicate that pressurization under the volcano continues as the intruded volume of magma into the system increases and as magma moves towards the surface.
Gas emissions from the crater, as observed from AVO Rendang (South sector) and AVO Batulompeh (North sector), appear as thin to thick white clouds that reach a height of 50-200 m above the crater rim.
Satellite Remote Sensing:
Satellites have detected steam emissions and thermal areas within the summit crater. During the crisis period, these areas have expanded along the north-east edge and including an area of emissions in the center of the crater.
Water expulsion in the crater near the solfatara field has been observed by satellite. Water expulsion is thought to reflect a disturbance to the hydrologic system in response to intruded magma at depth.
Tiltmeter observations showed a sudden deflation on October 1, 2017, but following days until today showed continued inflation.
Differential optical absorption spectroscopy (DOAS) gas measurements made at a distance of 12 km from the summit did not detect any SO2. This lack of detection can not necessarily be interpreted as a lack of SO2 or magmatic activity. SO2 concentrations may be below the detection threshold of the instruments, or emitted SO2 content may be reduced due to scrubbing (removal of SO2 gas as a result of interaction with water).
White smoke coming from the crater is potentially accompanied by the release of magmatic gases (CO2, SO2, etc.). If the concentration is high, these gases can smell, sting, and endanger the safety of those who inhale it. However, the current hazard from gas exposure is likely to be limited to the area around the crater. These gases will be easily blown and scattered by the wind so that the concentration will decrease significantly distance.
MultiGas measurements at Mt. Batur do not indicate the supply of new magma under Batur. As of today, all indications suggest that all recent activity is related to Mt. Agung.
The evaluation of observational data indicates that volcanic activity at Mt. Agung remains at a high level. It is still more likely than not that an eruption will result from current activity. Probabilities of eruption, however, can change with time and are dependent on changes in observational data.
If an eruption were to occur, it is likely that the first eruption would be small. Larger eruptions could follow initial, smaller eruptions. The size of impending eruptions, however, can not be forecasted precisely.
The exact date and time of a possible eruption can not be predicted. CVGHM will, however, issue warnings as early as possible if activity at Mt. Agung changes or if the probability of eruption increases.
Residents and tourists who remain outside of the hazard zone may continue their normal activities.The current hazard zone extends as a 9km radius from the summit and up to 12 km from summit towards the N-NE and SE-S-SW sectors.
Tourists activities are still considered safe in Bali. Residents and tourists, however, may not enter the Hazard Zones. CVGHM continues to work with BNPB (National Agency for Disaster Management) as well as local governments to improve eruption early warning systems.
Tourists and residents in Bali are encouraged to comply with recommendations set by the Government of Indonesia.
Source : CVGHM/Magma/VSI
Photo : Karl Kaddouri
Bárðarbunga , Iceland :
Earthquakes detected in both Grímsey and Bárðarbunga .
6 OCTOBER 2017. Several earthquakes were measured at Grímsey island north of Iceland last night as well as at Bárðarbunga but according to the Iceland Met Office there is no sign of volcanic unrest.
Two earthquakes at a magnitude of over 3 were measured at Bárðarbunga in the last 24 hours. The earlier one occurred yesterday morning just before 10 am and measured 3.7. The second occurred last night around 2 am and measured 3.4.
Yesterday afternoon an earthquake of 3.9 was detected at Grímsey followed by two more earthquakes last night at 3.5 and 3 consequently.
Source : ICELAND MONITOR
Fuego , Guatemala :
INCREASE IN THE ACTIVITY OF THE FUEGO VOLCANO .
The Volcanic Observatory of Volcano Fuego reports that over the past few hours there has been an increase in explosive activity, consisting of constant volcanic explosions, which are loaded with ash and which reach a height of about 5,000 m (16,404 feet). They spread over more than 20 kilometers to the west, southwest and south. The incandescent source reaches a height of 300 meters above the crater, generating falls of volcanic materials of different sizes (ballistics) to more than 600 meters and moderate to strong avalanches on the crater outline, with trajectories up to 1.5 km mainly in the ravines Ceniza and Seca.
The explosions are accompanied by moderate to strong rumblings which give rise to moderate to strong shock waves, causing vibrations in the roofs of houses in communities close to the volcano.
According to the observations of the seismic activity, the energy of the explosions is maintained, with the possibility that in the next hours new lava flows will be generated and a new eruptive phase will develop.
Source : Insivumeh.
Photo : Motophil
Mauna Loa , Hawaï :
19°28’30 » N 155°36’29 » W,
Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Mauna Loa Volcano is not erupting. Rates of deformation and seismicity have not changed significantly in the past week and persist at above-long-term-background levels.
Thirty-six microearthquakes were located beneath the upper elevations of Mauna Loa this week. Of these, most are shallow and beneath the summit caldera and upper southwest rift, at depths ranging between 0 and 5km (0 to 3mi). Seven microearthquakes were scattered beneath the upper western and northern flanks of the volcano.
Global Positioning System (GPS) and satellite radar (InSAR) measurements continue to show ground surface displacements consistent with inflation of a magma reservoir beneath the summit caldera and upper Southwest Rift Zone.
No significant changes in volcanic gas emissions or summit fumarole temperature were measured.
Source : HVO