Volcanic Activity Worldwide: Monday May 23, 2016

Ash emission from Nevado del Ruiz yesterday

Stromboli (Eolian Islands, Italy): The activity at the volcano has picked up recently and is now again at (fluctuating) moderate levels similar to what it has been during much of the past 10-15 years – extremely rewarding for those who climb it in the evening.
Apparently, the magma column inside the conduits has again risen and both the eastern, central and western vent are active and produce intermittent strombolian activity of various intensity.

A friend of ours described her visit on Saturday as follows:

Etna (Sicily, Italy): (22 May) Yet another paroxysm could be under way from the summit craters: after a calm day, strong strombolian eruptions have started a few hours ago from the NE crater. Along with the volcanic tremor signal which is rising again, the activity has been gradually increasing.
This might be the beginning of another paroxysm (if strombolian activity from the NE vent is a precursor of more violent activity of the Voragine or even the NE crater – the near future will tell…)
You can follow the activity live at various webcams.
…23 May:
Contrary to what it might have looked like, the volcano’s activity from last night did not continue to increase, but quieted down for now.
Strombolian activity from the Northeast crater seems to have ceased during the second half of the night or early this morning. However, the volcano remains very restless: sporadic ash emissions occurred from the New SE crater and tremor remains slightly elevated, but shows no clear trend right now.

Bagana (Bougainville Island, Papua New Guinea): Mild eruptive activity continues at the volcano. Darwin VAAC reported an ash plume that rose to 7,000 ft (2.1 km) altitude and drifted west yesterday.

Bromo (East Java, Indonesia): Ash emissions from the volcano were reported earlier today by Darwin VAAC. Based on satellite observations, a plume of light ash is drifting 50 km to the NE at approx. 10,000 ft (3 km) altitude.

Dukono (Halmahera): No significant changes have occurred at the volcano. It emits near-constant ash plumes, which are regularly seen on satellite imagery.

Santiaguito (Guatemala): Very elevated activity continues at the active Caliente lava dome. Yesterday, another two strong explosions occurred at 08:30 and around 13:00 local time.
Both explosions produced tall ash plumes that rose 3-4 km above the dome, reaching altitudes of 15,000-20,000 ft (4.5 – 6 km) as well as triggering several pyroclastic flows that descended several kilometers on the flanks of the dome.

Interestingly, the first explosion at 08:30 was described by CONRED as silent; apparently it did not produce any noise audible in surrounding villages, much unlike almost all previous eruptions.
The frequent explosions are beginning serious problems related to ash falls. Determined by the prevailing winds, ash plumes from the explosions again drifted W and SW, causing ash fall in the same areas that have been subject to fallout during much of the previous weeks already: Nuevo Palmar, San Marcos Palajunon, Coatepaque and others.

Fuego (Guatemala): The 10th paroxysmal eruption in 2016 is in progress at the volcano: starting yesterday, explosions have become stronger and more frequent. As the magma output rate increased strongly, the explosions have turned into pulsating lava fountains and a lava flow began to travel down the Las Lajas ravine on the SE flank, currently reaching about 1200-1500 m length.
INSIVUMEH reports moderate to strong explosions, glowing avalanches in all directions and noisy rumblings similar to a locomotive train.

The FG3 seismic station records strong tremor and rockfall signals. An ash plume is rising to approx. 5000 m elevation and drifting SW and W, where ash fall is occurring in areas such as the volcano observatory in Panimache, Morelia, and El Porvenir villages.

Turrialba (Costa Rica): The eruptive activity of the volcano has remained steady with near-constant ash emissions with occasional increases. According to RSN, the level of seismic activity, dominated by volcanic tremor, gradually increased during Saturday and remained fluctuating yesterday, with an overall stable trend.
Bad weather prevented detailed observations during the past 48 hours, but light ash fall is expected in areas downwind (currently west and northwest).

Nevado del Ruiz (Colombia): The volcano remains restless and produces intermittent ash explosions of varying size. An emission of ash yesterday forced the regional La Nubia airport to close down for a few hours and the volcano observatory reported a new pulse likely occurring a short time ago.
While many emissions cannot be directly observed due to cloud cover, they have been rather frequent recently. Similar explosions were also observed on 17, 18, and 20 May when fine ash fall occurred in Manizales town 30 km northwest of the volcano.

According to SGC (Colombian Geological Survey), the volcano’s seismic activity remains elevated at fluctuating levels, but has been showing a slight decrease overall during the past weeks. It continues to be dominated by internal fluid movements which reflect the interaction of water and magmatic gasses at shallow depth that occasional results in explosions and more often in a strong degassing plume reaching up to 1500-2000 m height.
A particular kind of seismic activity – so-called drum-beat signals – were also observed on 13 May. These are short regular pulses of tremor believed to result from regular sudden, stick-slip movements of viscous magma inside a conduit.

Bristol Island (United Kingdom, South Sandwich Is): The latest eruption likely continues. On recent satellite images, a strong heat source caused by lava is still visible at the summit vent of the remote volcano.

Currently erupting:

Ambrym (Vanuatu): active lava lakes in several craters (updated 13 May 2016)
Aso (central Kyushu, Japan): degassing, sporadic steam / ash explosions (updated 8 Mar 2016)
Bagana (Bougainville Island, Papua New Guinea): intermittent mild ash emissions (updated 23 May 2016)
Batu Tara (Sunda Islands, Indonesia): strombolian explosions, ash plumes up to 500 m, extrusion of a small lava dome with rockfalls (updated 28 Nov 2015)
Bristol Island (United Kingdom, South Sandwich Is): new eruption since late April 2016 (updated 23 May 2016)
Chikurachki (Paramushir Island): new eruption since end of March 2016 (updated 31 Mar 2016)
Colima (Western Mexico): intermittent mild to moderate explosions (updated 20 May 2016)
Copahue (Chile/Argentina): seismic unrest, occasional ash venting (updated 22 Mar 2016)
Dukono (Halmahera): mild strombolian activity, continuous intense ash emissions (updated 23 May 2016)
Erebus (Antarctica): active lava lake in summit crater (updated 8 Dec 2014)
Erta Ale (Danakil depression, Ethiopia): overflowing lava lake (updated 2 Mar 2016)
Etna (Sicily, Italy): weak, dilute ash emissions from NE crater (updated 19 Apr 2014)
Fuego (Guatemala): lava flows on S and W flanks, lava fountaining from summit vent (updated 23 May 2016)
Ibu (Halmahera, Indonesia): stromolian and phreatomagmatic explosions (updated 29 Oct 2015)
Karymsky (Kamchatka): occasional small explosions, thermal anomaly (updated 5 May 2016)
Kerinci (Sumatra): intermittent ash emissions (updated 1 May 2016)
Kilauea (Hawai’i): new lava flow from vents on NE flank of Pu’u ‘O’o (updated 28 Apr 2015)
Kliuchevskoi (Kamchatka): mild strombolian activity in summit crater (updated 27 Apr 2016)
Langila (New Britain, Papua New Guinea): ash emissions (updated 13 May 2016)
Masaya (Nicaragua): active lava lake ini summit crater (updated 6 May 2016)
Momotombo (Nicaragua): intermittent vulcanian explosions (updated 29 Mar 2016)
Nevado del Ruiz (Colombia): intermittent mild to moderate ash emissions (updated 23 May 2016)
Nyiragongo (DRCongo): new vent on crater floor (updated 8 Mar 2016)
Ol Doinyo Lengai (Tanzania): effusion of natrocarbonatite lava inside the crater (updated 8 Jul 2013)
Pacaya (Guatemala): intense spattering from intra-crater cone (updated 29 Mar 2016)
Popocatépetl (Central Mexico): degassing, sporadic explosions, slowly growing lava dome (updated 20 Apr 2016)
Rabaul (Tavurvur) (New Britain, Papua New Guinea): lava fountains, ash emissions from Tavurvur cone (updated 12 Sep 2014)
Reventador (Ecuador): lava flow on SW flank (updated 24 Feb 2016)
Sakurajima (Kyushu, Japan): sporadic vulcanian explosions from Minamidake and Showa crater (updated 20 May 2016)
Sangay (Ecuador): mild strombolian activity in summit crater (updated 20 May 2016)
Santiaguito (Guatemala): intermittent strong explosions from growing Caliente dome (updated 23 May 2016)
Semeru (East Java, Indonesia): growing lava dome, lava flow, strombolian activity (updated 14 Feb 2016)
Shiveluch (Kamchatka): growing lava dome (updated 9 May 2016)
Sinabung (Sumatra, Indonesia): continuing pyroclastic flows (updated 22 May 2016)
Stromboli (Eolian Islands, Italy): weak, intermittent strombolian explosions (updated 23 May 2016)
Suwanose-jima (Ryukyu Islands): strombolian explosions in Ontake crater (updated 20 Apr 2016)
Tungurahua (Ecuador): large and frequent explosions, ash columns rising several km (updated 9 Mar 2016)
Turrialba (Costa Rica): near-continuous ash emissions, explosions with ash plumes up to 3-4 km height (updated 23 May 2016)
Ubinas (Peru): sporadic vulcanian explosions (updated 16 Jan 2016)
Villarrica (Central Chile): lava lake in summit crater, spattering, strombolian explosions (updated 4 Apr 2016)
Yasur (Tanna Island, Vanuatu): ash emissions, weak strombolian explosions (updated 13 Nov 2015)
Zhupanovsky (Kamchatka, Russia): steaming / degassing (updated 31 Mar 2016)