Source: Volcano Discovery
Etna (Sicily, Italy): (19 May) The second paroxysm from the Voragine summit crater ended gradually during the course of today. Bad weather prevented detailed observations for most of the time.
At the moment, the lava flow from the new vent at the eastern base of the North-East crater is still visible, but effusion has either stopped or strongly decreased.
ETNA UPDATE, 19 MAY 2016, 11:00 UTC (INGV Catania’s official update)
During the afternoon of 18 May 2016, the lava fountaining activity from Etna’s Voragine crater passed into a modest Strombolian activity, which continued to feed the lava overflow toward west until the late evening (see first image at left, recorded by the thermal camera at Bronte, EBT).
Alaid (Northern Kuriles): Over the past week, activity of the volcano seems to have been declining. The satellite-based observation of heat output has been decreasing, suggesting that the eruption might be waning or ending.
According to the latest Smithsonian / USGS Weekly Volcanic Activity Report from 11-17 May 2016, the eruption of “Alaid continued during 6-13 May. Satellite images showed an intense daily thermal anomaly over the volcano and a lava flow on the SW flank. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).”
Chirpoi (Kurile Islands, Russia): A weak thermal anomaly over Snow, a volcano of Chirpoi, was detected in satellite images during 9-11 and 14 May. The Aviation Color Code remained at Yellow.
Sakurajima (Kyushu, Japan): In the past days, the volcano has been back to its typical activity of intermittent, but often strong vulcanian-type explosions at irregular intervals between several days or only few hours with almost no visible activity in between.
During 15-18 May, 9 explosions with ash plumes up to 15,000 ft altitude were recorded. No explosion has occurred during the past 48 hours, though.
JMA reported that an explosion at the Minamidake summit crater (at Aira Caldera’s Sakurajima volcano) generated an ash plume that rose 3.7 km above the crater rim.
Ruapehu (North Island): On 17 May GeoNet reported that the lake temperature of Ruapehu’s summit Crater Lake had decreased from a high of 46 degrees Celsius to 39 degrees, with some of the decrease attributed to rain and snowfall.
Moderate levels of volcanic tremor continued, and analysis of water samples collected the previous week showed no changes in the lake chemistry. During recent visits, scientists measured a larger output of volcanic gases. The Volcanic Alert Level remained at 2 (moderate to heightened unrest) and the Aviation Colour Code remained at Yellow.
(from: Smithsonian / USGS Weekly Volcanic Activity Report 11-17 May 2016)
Cleveland (Aleutian Islands, Alaska): After the small explosions at the volcano on 5 and 10 May, no further unusual activity has been noted on satellite and seismic data until 14 May.
The Alaska Volcano Observatory detected “energetic steaming and highly elevated surface temperatures in the summit crater” on 15 May. The Level of Concern Color Code remained at Orange and the Volcano Alert Level remained at Watch.” (AVO)
Colima (Western Mexico): The activity of the volcano has remained essentially unchanged over the past months and is currently relatively low.
Growth of a small lava dome continues in the summit crater (as indicated by some glow at night) and small to moderate explosions occur at rates of a few per day. Ash plumes have been reaching 1-4 km height above the crater during the recent week.
Santiaguito (Guatemala): The current phase of intense activity at the active Caliente lava dome continues. Two more explosions occurred yesterday, at 09:34 and 09:56 local time, producing ash plumes that rose 2-3 km to 15,000 ft (4.5 km) altitude.
Loud detonations accompanied the eruptions which also generated pyroclastic flows. Ash fall occurred in up to 25 km distance to the south and southwest, in particular in the farms of El Faro, Patzulin, Monte Bello, as well as in Loma Linda, San Marcos Palajunoj, Las Marias and other villages of the municipality of San Felipe in the department of Retalhuleu.
Fuego (Guatemala): (19 May) A relatively large pyroclastic flow (avalanche of hot debris and ash) descended from the volcano yesterday (18 May) morning at around 10:30 local time.
The unusual aspect is that it occurred during a phase of currently low activity with no active lava flow or intense explosive activity (as during the paroxysms). There seemed not to have been any precursor signs either.
The most likely cause should be a collapse of accumulated, unstable material from previous eruptions on the upper slopes, something that would not be too unusual to happen.
Turrialba (Costa Rica): The activity at the volcano has increased during the past days and ash emissions from the active crater with intermittent stronger explosions have been near-continuous since yesterday.
A more violent phase of explosive activity began this morning at 07:29 local time, producing an ash column that rose about 3000 m above the crater to approx. 20,000 ft (6 km) altitude.
The most energetic phase lasted about 6 minutes and produced pyroclastic flows from collapsing parts of the ash column that affected the central crater and eastern rims.
An ash plume drifted eastwards and caused moderate to light ash falls in up to 60-70 km distance. A strong smell of sulfur was reported by eyewitnesses from various towns including San Rafael and San Francisco (50 km ENE).
Nevado del Ruiz (Colombia): The Manizales volcano observatory reported that sporadic mild ash emissions continue to occur at the volcano, last on 17 and 18 May.
from the Smithsonian / USGS Weekly Volcanic Activity Report 11-17 May 2016:
“During 10-16 May seismicity at Nevado del Ruiz was characterized by long-period and very-long-period earthquakes, episodes of continuous tremor, and pulses of volcanic tremor associated with gas-and-ash emissions.
Thermal anomalies near Arenas Crater were identified in satellite images during 11-12 May. Significant amounts of water vapor and gas rose from the crater during the week. A gas, steam, and ash plume rose 1.7 km and drifted NW and W on 12 May.
Sangay (Ecuador): The mild eruption that had started in early March continues with no significant changes.
According to IGEPN, the number of tremor events and long-period earthquakes were slightly higher in March as compared to the number recorded in April and May, and the number of explosions was slightly higher in April and May.
Surficial activity was characterized by frequent ash emissions generated by explosive activity. Thermal anomalies on the flanks were also detected, mostly within 5 km of the summit crater, which possibly corresponded to short-range pyroclastic flows and lava flows. No abnormal sulfur dioxide emission were detected.
Cotopaxi (Ecuador): During an overflight of Cotopaxi on 10 May, scientists observed minor gas emissions rising 600 m above the crater and drifting N and NW. Glaciers remained cracked, though glacial melting observed in recent months had decreased considerably. The temperature of flank fumaroles had decreased slightly.
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)
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 4 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 13 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 19 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)
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): increased effusive / explosive activity from Caliente dome (updated 20 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 16 May 2016)
Stromboli (Eolian Islands, Italy): weak, intermittent strombolian explosions (updated 13 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 20 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)