December 30 , 2016. EN. Bulusan , Bogoslof , Kilauea .

Home / Alaska / December 30 , 2016. EN. Bulusan , Bogoslof , Kilauea .

December 30 , 2016. EN. Bulusan , Bogoslof , Kilauea .

December 30 , 2016.

 

Bulusan , Philippines :

BULUSAN VOLCANO BULLETIN 30 December 2016 8:00 A.M.

Bulusan Volcano generated a phreatic eruption from its southeast vent yesterday, 29 December, at 2:40 PM. The event was recorded as an explosion-type earthquake that lasted approximately 16 minutes based on the seismic record. This event produced a grayish to dirty white ash plume 2 kilometers high that drifted towards the general west-southwest direction. Thin ash fell on the Barangays of Cogon, Tinampo, Bolos, Umagom, Gulang-gulang and Monbon of Irosin and Caladgao and Guruyan of Juban, Sorsogon Province. Sufuric smell was experienced in Brgys. Guruyan, Juban and Monbon and Tinampo, Irosin. In addition, Bulusan’s seismic network recorded a total of twenty-two (22) volcanic earthquakes during the past 24 hours. Sulfur dioxide (SO2) emission was measured at an average of 60 tonnes/day on December 24, 2016. Precise leveling data obtained on October 17-23, 2016 indicated inflationary changes of the edifice relative to August 2016. Inflation was also recorded by continuous GPS measurements as of December 2, 2016, indicating pressurization beneath the volcano edifice.

 

 

 bulusan

Alert Level 1 (abnormal) remains in effect over Bulusan Volcano. This indicates that hydrothermal processes are underway beneath the volcano that may lead to steam-driven or phreatic eruptions. Local government units and the public are reminded that entry into the 4-kilometer radius Permanent Danger Zone (PDZ) is strictly prohibited and that vigilance in the Extended Danger Zone (EDZ) must be exercised due to the increased possibilities of sudden and hazardous phreatic eruptions.

Source : Phivolcs .

Photo : Mon Lorilla

 

Bogoslof , Aleutians Islands , Alaska :

53°55’38 » N 168°2’4″ W,
Summit Elevation 492 ft (150 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Summary of current activity
Bogoslof volcano is in an active eruption sequence that began on December 16, though retrospective analysis suggests unrest may have started earlier in December. Eruptive activity has been dominated by a series of explosive events lasting from about 30 to 60 minutes each. These explosions have occurred on December 16, 19, 20, 21, 23, 26, and 28 (local time). The intensity of these explosions have varied. The largest events to date were on December 21 and 26, which produced water-rich and relatively ash-poor volcanic clouds that rose as high as 10.7 km (35,000 ft) above sea level and were tracked in satellite images as they were transported with the prevailing winds. Sulfur dioxide gas clouds from many of these events have been detected in satellite data, and the largest event on December 21 was tracked in satellite data for five days to a location over the central United States (Nebraska).

We have had very few direct observations of the activity at Bogoslof due to its remote location, cloud cover, and limited daylight hours. The event on December 20 was observed by pilots, who saw an ash plume rising out of the ocean. During the December 23 event, observers aboard a Coast Guard vessel reported ash emission, lightning, and the ejection of incandescent lava and fragmental material.

 

AVO Image

Map of Bogoslof Island showing changes in surface configuration as of Dec. 25, 2016. These changes are the result of the December 2016 eruptive activity. The map shows areas where new land area was generated by the emplacement of eruptive products, most likely volcanic ash, and areas of Bogoslof Island removed by the eruption. Worldview 3 satellite images obtained on March 19, 2015, and December 25, 2016 were used to make this map.

 

High-spatial-resolution satellite images show that the explosions have dramatically altered Bogoslof Island (http://www.avo.alaska.edu/images/image.php?id=103521). A new vent has developed at the northeast end of the island, immediately offshore. Explosions have formed a new cone of fragmental rock and ash, and portions of the old island have been destroyed. The location of the vent in shallow seawater has produced water-rich eruption clouds that are characterized by abundant lightning (due to ice formation in the cloud). The clouds are also relatively dispersed and ash poor due to enhanced removal of volcanic ash near the vent.

Monitoring Status
Bogoslof is not monitored by a local, on-island geophysical network, which limits our ability to forecast activity at this volcano. AVO is using seismic and infrasound (pressure) sensors from Okmok and Makushin volcanoes on neighboring Umnak and Unalaska Islands to monitor activity, as well as more distant infrasound sensors in Dillingham and Sand Point. Due to the distance from Bogoslof, these sensors can detect signals produced by large explosive events, but they are not sensitive enough to detect lower-level signals that could help forecast imminent eruptions. Since the pressure waves move at the speed of sound, there is a delay of tens of minutes between eruption onset and detection at distant infrasound sensors. In addition, storms are common in the Aleutians during this time of year, and seismic and infrasound signals are often masked by wind-generated noise.

 

 

bogoslof

Near-real-time satellite data are being used to detect explosive eruptions, to estimate volcanic cloud height and to track the dispersion of the resulting volcanic clouds. These data can also detect highly elevated surface temperatures from lava effusion or hot ash deposits, but none have been observed to date. Data from the World Wide Lightning Location Network (http://wwlln.net/) provide near-real-time automated alerts of lightning strikes near Bogoslof that have been shown to be indicative of explosive activity at the volcano.

AVO will continue to provide timely warnings of activity to the best of our ability and will issue Volcanic Activity Notices (VANs) and Volcanic Observatory Notices for Aviation (VONAs) as needed. Based on the current level of activity and potential for eruption, Bogoslof remains at Aviation Color Code ORANGE and Volcano Alert Level WATCH. Should we detect additional explosive events that pose a significant hazard, we will change the Aviation Color Code to RED and Volcano Alert Level to WARNING.

 

Source : AVO:

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

Activity Summary:
Kilauea Volcano continues to erupt in two locations. The episode 61g lava flow from Pu’u ‘O’o in the East Rift Zone is entering the ocean at Kamokuna. A younger branch of the flow is active near Pu’u ‘O’o and advancing slowly eastward. These lava flows pose no threat to nearby communities at this time. The lava lake at Kilauea’s summit continues to circulate, with intermittent periods of spattering, and is visible from the Jaggar Museum. Inflationary tilt continues this morning. Seismic activity continues at a low rate overall.

kilauea

L’étang de lave de Pu’u’Oo continue d’être actif, car sa surface bouillonnante et agitée a avalé des plaques de croûte refroidie.


Summit Observations:
The average daily sulfur dioxide emission rate at the summit was between 5,000 and 2,700 metric tons/day during the past week. Summit seismicity has varied with lava lake spattering and non-spattering intervals but activity remains low overall. Summit inflationary tilt began Tuesday evening, and is continuing this morning. The level of the summit lava lake this morning is about 16 m (52 feet) below that of the adjacent crater floor, a rise of about 8 m (26) in the past 24 hours.

kilauea

 The skylights high on Pu’u ‘O’o’s northeast flank still glowed with intensity, and gave us a view of the river of molten lava supplying flow 61G.


 
Pu’u ‘O’o Observations:
There were no obvious changes at Pu’u ‘O’o. Webcam views show persistent glow from sources within the crater and from a vent high on the northeast flank of the cone. The tiltmeter on the northwest flank of the cone recorded no significant change in tilt over the past day. The sulfur dioxide emission rate from all East Rift Zone vents was about 260 metric tons/day when last measured on December 27. Seismicity in the Pu’u ‘O’o area continues at low levels.

kilauea


Lava Flow Observations:
The episode 61g flow is still active and entering the ocean at Kamokuna, where activity has been concentrated on the east side of the delta. In addition, a younger branch of the episode 61g vent remains active east of Pu’u ‘O’o and is advancing slowly east at a rate of only a few tens of meters (yards) per day. A small breakout near Pu’u ‘O’o, active recently continued, visible on webcams overnight. The episode 61g flow poses no threat to nearby communities at this time.

Source : HVO

Photo : Bruce Omori , HVO.

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