26 November 26 , 2017. EN. Agung , Ruapehu , Sierra Negra , Popocatepetl .
November 26 , 2017.
Agung , Indonesia :
AMLAPURA, BALIPOST.com – The Gunung Agung continues to erupt. Since the first phreatic eruption of Saturday (25/11) at 17:30, with a height of 1500 meters above the top of the crater, the eruption is still ongoing.
This Sunday (26/11) at 05.05 the eruption occurred with a dark gray column height, high pressure, reaching 2,000 meters, then at 05,45 the height reached 3,000 meters. The PVMBG continually reports the eruption developments at the BNPB Post and the community.
On Sunday 26/11 at 06:20, the height of the eruption reached 3,000 to 4,000 meters above the summit, facing southeast, at a speed of 18 km per hour. The analysis of the volcanic ash propagation of the Himawari satellite shows that the ash dispersal is moving east and south-east to Lombok.
The PVMBG issued a flight warning (VONA, Volcano Observation Notice for aviation) carried from Orange to Rouge.
Gunung Agung’s alert status is still level 3 alert with activity restrictions within 6-7.5 km radius of the crater People who are still in the dangerous radius immediately evacuate in an orderly manner.
According to BNPB chief of data, information and public relations center, Sutopo Purwo Nugroho, Sunday (26/11) in a statement, despite this successive eruption, no increase in volcanic activity is noted. The number of shallow volcanic earthquakes is up to 5.4 deep volcanic earthquakes, and a continuous tremor (microtremor) is recorded with an amplitude of 1 to 2 millimeters (dominant at 1 millimeter). No seismic peaks.
Ash falls have been reported in several places, including Duda Timur village, Pempetan village, Sideman village, Tirta Abang village, Sebudi village and Amerta Bhuana village in Klungkung. They also occurred in some villages of Gianyar.
Evacuations are autonomous and orderly. The number of refugees is still being evaluated. The BPBD in collaboration with SKPD, Basarnas, TNI, Polri, PMI, and volunteers distributed masks to the public.
BPBD NTB Province has requested that BPBDs West Lombok, BPBD Mataram and BPBD North Lombok immediately report the impact of ash rains in these areas.
VSI post of 25/11
The eruption of Mount Agung occurred at 17:30 WITA. Gray columns were observed up to 1500 meters above the summit of Mount Agung. Ash emission is weakly emitted to the west. The communities remain calm and follow the recommendation of the PVMBG on the level III status (Siaga) not to engage in an activity within a radius of 6 km plus a sectoral extension of 7.5 km to the North-North-East , South-East and South-South-West. The risks of the estimated danger zones are dynamic and continuously assessed and may change at any time based on the most recent observational data from G. Agung.
VOLCANO OBSERVATORY NOTICE FOR AVIATION – VONA.
Issued: November 26 , 2017
Volcano: Agung (264020)
Current Aviation Colour Code: RED
Previous Aviation Colour Code: orange
Source: Agung Volcano Observatory
Notice Number: 2017AGU18
S 08 deg 20 min 31 sec E 115 deg 30 min 29 sec
Area: Bali, Indonesia
Summit Elevation: 10054 FT (3142 M)
Volcanic Activity Summary:
Eruption with volcanic ash cloud at 21h45 UTC (05h45 LT). Eruption and ash emission is continuing.
Volcanic Cloud Height:
Best estimate of ash-cloud top is around 19654 FT (6142 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer.
Other Volcanic Cloud Information:
Ash coud moving to east-southeast
Seismic activity is characterized by low frequency earthquakes.
International airlines including Jetstar and Qantas have cancelled flights to and from Bali after the second eruption of Mt Agung in a week, even though Indonesia’s disaster management authorities say it’s safe to fly to the island.
The latest eruption is significantly stronger than last Tuesday’s eruption, with a cloud of steam and pulverised rock driven at least 1,500 metres above the volcano’s 3,000-metre peak.
There have been no new evacuations in Bali and a 6 kilometre exclusion zone around the volcano has not been extended.
Ngurah Rai airport in Denpasar remained open on Saturday night but within two hours of the eruption, Jetstar cancelled or diverted four flights heading to Bali as well as five flights due to depart from the island.
Qantas, Virgin and Dutch airline KLM soon followed Jetstar’s lead in cancelling flights.
The pulverised rock contained in volcanic ash can cause significant damage to aircraft engines but airlines have different criteria about how close to ash clouds their planes can operate.
Indonesia’s Garuda and Air Asia were continuing to use Ngurah Rai airport.
A spokesman for Indonesia’s National Disaster Management Agency said the ash cloud was not affecting Denpasar’s flight paths and stated that it was still safe to fly in and out of the airport.
Source : VSI / Magma , abc.net.au.
Ruapehu , New Zealand :
High volcanic gas emission and Crater Lake (Te Wai Ā-Moe) temperature at Mt Ruapehu , Published: Sat Nov 25 2017 10:00 AM .
Volcanic Alert Bulletin RUA – 2017/01
2017-11-25 10:00:00 +1300 +1300; Ruapehu Volcano
Volcanic Alert Level remains at 1
Aviation Colour Code remains at Green
An increase in volcanic gas emissions and sustained high lake temperature suggest a slightly higher level of activity at Mt Ruapehu. The Volcanic Alert Level remains at 1.
The recent fine weather has allowed GeoNet to make airborne gas measurements over Mt Ruapehu. These recorded high levels of CO2, SO2 and H2S emission from the Crater Lake (Te Wai Ā-Moe). The CO2 emission rate on 23rd November was 2290 tonnes/day, one of the largest values recorded in recent years. The current lake temperature is 37° C, which is near the top of its usual range and has been sustained over the past 2 months.
The data are consistent with open vent degassing of Ruapehu. Higher than usual temperatures and high gas fluxes like we have now are common in the open vent situation and have been observed in the past outside eruptive periods. Volcanic seismic tremor remains at moderate levels. The fine weather has also allowed the taking of water samples from Ruapehu Crater Lake and the analysis of these samples is underway.
GNS Science continues to closely monitor Mt Ruapehu and our other active volcanoes through the GeoNet project. The Volcanic Alert Level of Ruapehu remains at 1 and the Aviation Colour Code at Green.
Source : Geonet.
Sierra Negra , Galápagos , Ecuador :
The Sierra Negra volcano, located on Isabela Island, is one of the most active volcanic centers of the Galapagos. Recently, the monitoring network of the Institute of Geophysics of the National Polytechnic School has detected significant increases in the number of earthquakes and the deformation of this volcano. Since October 20 this year, at least five of them have been recorded with magnitudes greater than 3.0, with epicentres under or around the boiler, some of which were felt by people in the room. ‘in law. On the other hand, a survey of the caldera of the volcano of the order of 70 cm per year continues to be recorded, which surpasses the rise that it had before the eruption of 2005. This level of deformation is one the highest recorded globally in volcanic areas, making a new eruption period likely.
RECENT SEISMIC ACTIVITY:
The seismic stations of the IGEPN have shown in the last months of 2017 an increase in the number of local earthquakes in Sierra Negra ( figure 1 ) . This increase becomes clearer since July 2017. Most earthquakes are of the Volcano – Tectonic type (VT) with some Long-Period (LP) events and Hybrid (HB) earthquakes. The epicenters of these earthquakes are located below and around the Sierra Negra caldera (Figure 2).
Figure 1. Epicentral location of events since August 2017. The earthquakes registered since October are plotted in red. The VCH1 and PVIL stations are indicated by a square. The information is taken from the Seiscomp3 processing system of IGEPN.
Figure 2. Epicentral location of events since August 2017. The earthquakes registered since October are plotted in red. The VCH1 and PVIL stations are indicated by a square. The information is taken from the Seiscomp3 processing system of IGEPN.
The most important earthquake (magnitude 3.8) was recorded on October 20 at 00h07 GMT or 18h07 on October 19 (local time) . This is the largest magnitude earthquake recorded during 2017 in the Galapagos Islands. Its hypocentre was located 16 km under the Chico volcano on the edge of the Sierra Negra caldera . This earthquake is classified as an LP-deep earthquake (DLP by its acronym in English – Deep Long Period) for its focal depth and its spectra with predominance of energy between 0.3 and 3.0 Hz and the notable absence of high frequencies (> 5 Hz ) that correspond to fracture earthquakes . It should be mentioned that at 15 km depth there is the lower limit of the continental crust (Moho), according to the results indicated by Tepp et al. (2013).
Seismic signals of the vertical components of stations VCH1 and PVIL and their respective spectra in the log-log scale.
A second important event occurred on October 22, at 13h05 GMT. It is an earthquake with impulsive arrivals in seismic stations and mixed polarities (VCH1 is negative and PVIL is positive). At the closest station located in Chico Volcano there is a peak frequency of 3 Hz and an absence of significant amplitudes less than 1 Hz. This suggests that this earthquake is a hybrid type…/…
The fact that these earthquakes have impulsive starts and a variety of polarities and that have spectra with the most energy at frequencies below 3 Hz, suggests that they start with a fracture process followed by a vibration of fluids in a crack in the interior of the volcano, reason why they are considered like Hybrid type earthquakes. At greater distances, low frequency waves are mainly observed.
The earthquakes of October 20 and 22, November 2 and 3 and some earthquakes last week were reported as felt by some people in the entrance area to the National Park on the flanks of the Sierra Negra volcano.
Maps of deformation of the surface of the land in the Galápagos were elaborated with the radar satellite interferometry method (InSAR) by researchers from the School of Atmospheric and Marine Sciences of the University of Miami (RSMAS), which show a rapid inflation of the floor of the caldera of the Sierra Negra volcano. In the last year, the lifting rate was 70 cm / year . This deformation represents an order of magnitude greater than that of the Mauna Loa volcano (70 mm / year), which is the largest deformation reported in Hawaii in the 2013-2017 period. It is also important to note that this deformation has already overcome the deformation that preceded the eruption of Sierra Negra in 2005 .
Deformation map of the boiler detected by InSAR in the Galapagos Islands. There is a very important deformation in the interior of the Sierra Negra caldera and a moderate deformation in the SE flank of the Cerro Azul volcano in the period January – November 2017. Courtesy of Dr. Falk Amelung (RSMAS).
According to the eruptive history of the Sierra Negra volcano with an interval between eruptions of 11.4 years and its last eruption in 2005, a reactivation of this volcano is considered very probable.
The number of earthquakes shows a sustained increase in 2017, especially since July of this year. The located earthquakes are located low in the surroundings of the caldera of the volcano.
In October and November, earthquakes with magnitudes greater than those registered in the previous months were recorded. The largest magnitude earthquake, 3.8, occurred on October 20.
The observed elevation of the floor of the boiler shows a very high rate and has reached a level higher than that shown before the eruption of 2005. Generally when there are accelerations of the deformation rates it is considered that an eruption would be approaching.
Source : IGEPN
Popocatépetl , Mexico :
Overflight of Popocatépetl Volcano , 25 November 2017
The volcanic alert level of Popocatepetl is located at Amarillo Phase 2.
Popocatépetl volcano is continuously monitored 24 hours a day. Any change in activity will be reported in a timely manner.
Today, with the participation of the staff of the National Center for Disaster Reduction (CENAPRED) and the support of the federal police, was conducted an overflight of the Popocatepetl volcano to assess the conditions inside the crater.
Based on the observations made during this overview, it was determined that the explosive activity recorded a few days ago was increasing the dimensions of the inner crater, reaching a diameter of 370 meters and a depth of 110 meters. It is possible that in the coming days or weeks, if the arrival of new materials to the surface continues, as has happened in previous weeks, little by little, the inner crater will be filled, at least partially, by a new dome of lava. Therefore, CENAPRED asks not to approach the volcano and in particular of the crater, because of the danger of falling projectiles and in case of rain, to remain far from the bottom of the ravines, because of the risk of landslides and flows mud.
Source : Cenapred.