Roundup of Global Volcanic Activity – New Activity for the week of 17 January – 23 January 2018

Kadovar | Papua New Guinea : RVO reported that the eruption at Kadovar continued during 18-19 and 21-22 January. Main Crater produced ash plumes that rose as high as 800 m above the summit and drifted tens of kilometers E, SE, S, and SW. Vulcanian activity was continuous, though no discrete explosions were detected. Steam plumes from the SE Coastal Vent rose 800 m above the island, and a lava dome which strongly and continuously glowed at night slowly extruded from the vent. Strong sulfur dioxide emissions were detected.

Kusatsu-Shiranesan | Honshu (Japan) : JMA reported that at 0959 on 23 January an eruption began at Kusatsu-Shiranesan coincident with the onset of volcanic tremor; there were no indications of an impending eruption. The Alert Level was raised to 3 (on a scale of 1-5). Skiers at the popular ski resort Kusatsu Kokusai took video showing a plume of tephra and ejected bombs rising from a vent on the Motoshiranesan edifice, about 2 km SSE of Yagama Crater on Shiranesan (where all previous historical activity has been). The eruption also caused what appeared to be an avalanche. Photos and video posted in news articles showed tephra drifting E and blanketing the nearby hillside; JMA noted ashfall in Nakanojo-machi, in the Gunma Prefecture. Tephra hit a gondola, shattering glass and injuring four skiers. Material crashed through the roof of a lodge, where about 100 people had already been evacuated. Ground Self-Defense Force troops were engaging in ski training at the time of the event; one member died and seven others were injured. Emergency responders gathered at the Sanroku Station to assist. On 24 January JMA noted that volcanic earthquakes were numerous but decreasing in number, and two 2-3-minute-long periods of volcanic tremor were detected at 1015 and 1049.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 16-17 January Mayon’s seismic network recorded 143 lava collapse events associated with rockfalls along the front and margins of advancing lava and pyroclastic flows in the Miisi (S), Matanag (SE), and Buyuan (SE) drainages. These events generated ash plumes that drifted SW. During 17-20 January effusion of lava at the summit and collapse events continued. Two pyroclastic flows traveled around 3 km down the Miisi drainage. Rockfall events were generated by the collapsing lava front and margins of the advancing 3-km-long lava flow in the Miisi drainage, and from the summit into the Matanag, Buyuan, and Bonga (SE) drainages. Ash plumes continued to drift SW. Sulfur dioxide gas emissions were 1,478 tonnes/day on 18 January and 1,131 tonnes/day on 19 January. During 20-21 January there were 14 rockfall events and 10 pyroclastic flows recorded by the seismic network.

During 21-22 January there were 64 rockfall events and one pyroclastic flow recorded. Strombolian activity generated lava fountains 500 and 200 m high at 1045 on 21 January and at 0225 on 22 January, respectively. Ash plumes rose 1.3 km high and drifted SW, causing ashfall in Oas and Guinobatan (12 km SW). Lava flowed more voluminously, adding to the advancing Miisi lava flow (over 3 km long) and feeding two new lava flows on the Bonga and upper Buyuan drainages.

At 1243 on 22 January an eight-minute-long phreatomagmatic event generated a dense, 5-km-high ash plume that drifted W. Ashfall was reported in the municipalities of Guinobatan, Camalig (11 km SSW), Oas, Polangui (20 km WNW), and Iriga City (34 km NW). The event also generated pyroclastic flows that traveled as far as 4 km down multiple drainages including Miisi, Bonga, Buyuan, Basud, San Andres, Buang, Anoling. PHIVOLCS raised the Alert Level to 4 (on a 0-5 scale) and extend the Danger Zone to an 8-km radius. A minor event at 1725 produced a 500-m-high ash plume. Between 2137 on 22 January and 0525 on 23 January there were five episodes of intense and sporadic lava fountaining, each lasting 3-30 minutes. The lava fountains rose 500-700 m high, and generated ash plumes that rose 2.5-3 km above the crater. The events fed lava flows on the Miisi and Bonga drainages, sprayed near-vent lava spatter, and fed incandescent rockfalls around the summit area. The Buyuan lava flow was 200 m long. According to news articles posted on 23 January about 40,000 people have been evacuated, and airports in the cities of Legazpi City (13 km SSE) and Naga (66 km NW), and on the nearby island of Masbate (100 km S) were closed.

Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported continuing explosive activity during 1-15 January associated with a low rate of lava-dome growth in the active crater. Gas plumes from the explosions rose less than 1 km above the crater rim, and sporadic incandescence associated with some explosions was recorded at night. The lava-dome growth rate was low at 1,360 m3/day, determined by photos taken during overflights on 9 and 12 January. The total volume of the lava dome was an estimated 37,000 m3. The Alert Level remained at Yellow, the middle level on a three-colour scale, and the public was reminded not to approach the craters within a 4-km radius.

San Miguel | El Salvador : SNET reported that during 14-17 January there were four gas-and-ash emissions from San Miguel that rose no higher than 300 m above the crater rim. The report noted that prior to each emission seismicity decreased and then suddenly increased.



Roundup of Global Volcanic Activity – Ongoing Activity for the week of 11 January-17 January 2017 – Cont.

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 13 January an ash puff recorded by a webcam rose from Nevados de Chillán and quickly dissipated. On 15 January a narrow ash plume observed in satellite images, by a pilot, and recorded by a webcam drifted W and dissipated.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 6-13 January lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, webcam views, and satellite images, the Darwin VAAC reported that during 11-17 January ash plumes from Sinabung rose to altitudes of 4-7.3 km (13,000-24,000 ft) a.s.l. and drifted N, NNE, E, SE, and S.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 17 January an ash plume from Suwanosejima rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted S.


Roundup of Global Volcanic Activity – New Activity

Bogoslof (United States, Aleutian Islands): Another (the 6th) large explosion seems to be occurring this morning at the volcano. The Alaska Volcano Observatory reported detecting a strong seismic signal (captured on neighboring islands) and a swarm of lightnings typical for large eruption ash plumes near the volcano and extending north (as the ash plume drifts in this direction). Weather cloud tops at 30,000 ft prevent visual and other satellite conformation (so far) of the likely ash plume which could have reached similar altitudes. The eruption started presumably at 22:30 local time (07:30 UTC Dec 29) and is continuing at the time of writing.

Ongoing Activity for the week of 21 December-27 December 2016

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 22 and 25-27 December ash plumes from Bagana rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted 45-85 km S, SW, and WSW.

Copahue | Central Chile-Argentina border : Based on satellite and webcam images, the Buenos Aires VAAC reported that during 21-23 December gas-and-ash plumes from Copahue rose to altitudes of 3.6-3.9 km (12,000-13,000 ft) a.s.l. and drifted SE and ESE.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 21-26 December ash plumes from Dukono rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted as far as 185 km NE, ENE, E, and SE.

Fuego | Guatemala : In a special bulletin from 21 December, INSIVUMEH reported the beginning of the 16th Strombolian episode in 2016 at Fuego. Ash plumes rose 1.5 km above the crater and drifted 18 km S, SW, W, and NW, and ashfall was reported in nearby areas including Morelia (9 km SW), Santa Sofía (12 km SW), Panimaché I and II (8 km SW), and Sangre de Cristo (8 km WSW). Lava fountains rose 200-300 m above the crater and fed three lava flows: the first traveled 2.5 km W down the Santa Teresa drainage, the second traveled 2 km SW down the Taniluyá Canyon, and the last traveled 1.8 km SE down the Las Lajas drainage. Shock waves from explosions rattled structures within a 12-km radius. During 24-27 December weak explosions generated ash plumes that rose 450-750 m and drifted 5-10 km W and SW.


Roundup of Global Volcanic Activity – Ongoing Activity for the week of 14 December-20 December 2016

Bogoslof (United States, Aleutian Islands): Another explosive eruption occurred at the volcano a few hours ago (at around 09:30 AKST local time), the Alaska Volcano Observatory reported. The alert level of Bogoslof was raised back to red. “A Coast Guard ship in the vicinity reported ash emission as well as ejection of lava and fragmental material. The eruption cloud did not penetrate the regional cloud tops at 30,000 ft and winds are to the north-northeast. According to the Coast Guard, ash emission subsided at about 10:37 AKST (19:37 UTC). On the basis of this information, the Aviation Colour Code is raised to RED and the Alert Level to WARNING.” (AVO)

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that during 17-18 December ash plumes from Suwanosejima rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted SE and SW.

Sinabung | Indonesia : Based on PVMBG observations, webcam views, and satellite images, the Darwin VAAC reported that on 15, 17, and 19 December ash plumes from Sinabung rose 3-5.8 km (10,000-19,000 ft) a.s.l. and drifted E and S.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 10-16 December lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Sabancaya | Peru : IGP’s OVS reported that during 12-18 December seismicity at Sabancaya continued to be dominated by long-period earthquakes; hybrid earthquakes decreased from 14 events per day to 6. Gas-and-ash plumes rose as high as 3.5 km above the crater and drifted more than 35 km NW, E, SE, and S.

Based on webcam and satellite views, the Buenos Aires VAAC reported that during 14-20 December gas-and-water-vapor emissions and sporadic ash puffs rose 6.4-8.2 km (21,000-27,000 ft) a.s.l. (2.3 km above the crater) and drifted SW, WSW, W, and NW.

Nevados de Chillan | Chile : According to ONEMI on 16 December, OVDAS-SERNAGEOMIN reported that in recent days there had been sporadic explosions at craters formed at Nevados de Chillán in 2016. The Alert Level remained at Yellow, the middle level on a three-colour scale, and the public was reminded not to approach the craters within a 3-km radius.

Kilauea | Hawaiian Islands (USA) :During 14-20 December HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent; the lake level rose as high as 13 m below the Halema’uma’u floor. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean near Kamokuna at the easternmost lava delta. An active branch of 61G remained active E of Pu’u ‘O’o and advanced slowly E at a rate of only a few tens of meters per day.


Roundup of Global Volcanic Activity

Pacaya (Guatemala): The volcano’s activity has been comparably calm recently, characterized by strong degassing from the intra-crater cone that formed during the latest period (2015-16) of strombolian activity and has become impressively large, filling a good part of the crater now. On a recent video, no ejections of lava fragments are visible, but rather near-continuous, pulsating emissions of steam and ash. These probably reflect an activity weaker than, but essentially similar to what we observed in Dec last year: spattering-type degassing (“bubbling”) from the magma column inside the cone, generating near-continuous small strombolian explosions. The only real difference would be that this time the effusion rate is too low and activity too deep to eject incandescent lava spatter.

Turrialba (Costa Rica): The volcano continues to be restless with intermittent mild eruptive phases. After 5 days of no visible activity, it restarted to emit low-energy plumes of gas, steam and ash yesterday. According to OVSICORI-UNA, the new phase of eruptive activity began at 7 am local time and was accompanied by a weak tremor signal, which increased from 11:30 am to fluctuating medium to high levels. The observed ash emissions have been weak and produced a plume that did not exceed 500 m. Easterly winds have been carrying the ashes into nearby areas west and northwest of the volcano

Cayambe (Ecuador): The volcano has become restless. Scientists from Ecuador’s Institute of Geophysics (IGEPN) recorded an increased number of earthquakes under the volcano a new report shows. The increased seismicity could be (but not must be) a precursor of renewed activity in the medium-term future (weeks, months?). An increase of earthquakes began on 5 June this year when a seismic swarm of earthquakes started which totalled more than 2300 events by the end of the month. The quakes occurred concentrated in an area NE of the volcano and were volcano-tectonic in origin, likely caused by a magma intrusion at depth causing pressurization and fracturing of rocks. After the June swarm, the volcano returned to calm again first. New earthquakes started to appear in increased numbers from September and have been continuing. Different from in June, the quakes have been concentrated under the summit area of the volcano and been showing an upward trend in depth. In addition, there have been increased reports of strong sulfur smell from climbers who visited the volcano, suggesting that there has been an increase in SO2 emission.


Roundup of Global Volcanic Activity

Sinabung (Sumatra, Indonesia): No significant changes have occurred in the ongoing effusive-explosive eruption of the volcano. The slow lava dome growth continues to feed a prominent lava lobe on the upper ESE flank that sheds glowing avalanches. Occasional larger collapses of this lava lobe produce more violent pyroclastic flows. In addition, the volcano continues to produce explosions, caused by trapped, pressurized gasses contained in the magma from the upper conduit or the dome itself. These vertical explosions have been occurring at rates of one per day on average recently. This morning, an ash plume rose to 15,000 ft (4.5 km) altitude, i.e. approx. 2 km above the summit.

Bromo (East Java, Indonesia): Mild to moderate ash emissions continue, generating a plume that rises up to 500-1000 m and drifts mostly northwest before dissipating.

Kilauea (Hawai’i): The latest mapping of the active lava flow in the coastal plain shows that the leading tip was about 870 m from the coast yesterday. Most of the activity in recent days has been the overriding and widening of the lava flow field, with only little net advance of the farthest lava front towards ocean. However, if the feeding of fresh lava through the main tube into the lava field in the coastal plain continues, and eventually establishes itself over increasing distance, it is more and more likely that the lava eventually reaches the sea. This is likely to occur in the near or medium-term future (days to weeks).

Santiaguito (Guatemala): A strong explosion (another in the ongoing series) occurred at the Caliente lava dome yesterday at 13:30 local time. According to INSIVUMEH, it generated an ash column that rose to approx. 5 km altitude, i.e. about 2500 m above the dome.

Piton de la Fournaise (La Réunion): The volcano is showing signs of unrest that could be (but not necessarily) precursors of a new eruption. Since the beginning of the month, shallow (0-2 km depth) volcanic earthquakes of rock-fracturing type under the Dolomieu crater (the main vent of the volcano) have been more frequent, probably caused by a new magma intrusion. The volcano observatory’s (OVPF) latest statement mentions that 111 “collapses” have occurred recently on the Dolomieu crater, the Enclos and on the lava flow of Aug-Oct 2015. In addition, it seems that new deformation has started during the past days, which would fit into the picture that the volcano is likely preparing itself for a new eruption, although the trend was still unclear and needs to be confirmed.


Roundup of Global Volcanic Activity

Kuchinoerabu-jima (Ryukyu Islands): The Japan Meteorological Agency (JMA), the official government body in charge of monitoring volcanoes, lowered the alert level for the island, after no more significant activity has occurred at the volcano since 19 June 2015 (i.e. almost one year). Current level was lowered from the second highest on the scale (4: “prepare for evacuation”) to now 3 (“Do not approach the volcano”).

Santiaguito (Guatemala): Heavy rainfalls in recent days generated strong lahars (mud flows) through the Nima I River bed, remobilizing some of the recently erupted loose volcanic debris. The turbulent hot flows reached 30 m width and carried blocks up to 50 to 70 cm in diameter, tree trunks and large branches.


Roundup of Global Volcanic Activity

Alaid (Northern Kuriles): A new eruption is occurring at the volcano, satellite images show. A pronounced steam plume with possible ash content can be seen drifting west from the volcano, at estimated 13,000 ft (4 km) altitude. In addition, NASA’s MODIS and VIIRS sensors have been detecting an intense heat source from the volcano’s summit lately. Tokyo VAAC raised the aviation color code to orange.

Manam (Papua New Guinea): New activity has been reported from the volcano this morning. A pilot reported an ash plume at approx. 10,000 ft (3 km) altitude extending 50 km to the SE. A plume, along with a thermal signal, can also be seen on the latest satellite image.

Bromo (East Java, Indonesia): The latest eruptive cycle of the volcano might have ended. No more eruptions (explosions, ash emissions) have been observed during the past 2 weeks and seismic activity has returned to normal levels as well.

Masaya (Nicaragua): The activity of the lava lake in the Santiago crater has been increasing in the past week. In a recent bulletin, INETER mentions that the previously two ponds in two adjacent vents have now joined, probably as a result of erosion by the violently degassing and convective lava.

Tungurahua (Ecuador): The volcano is in a phase of mild to moderate strombolian activity. Incandescent bombs are ejected to the upper slopes of the volcano, generating avalanches. Ash plumes rise up to a few km above the crater and drift mostly in westerly directions. Apparently, the large vent-clearing explosion on 27 Feb has opened the conduit to allow a sustained slow rise of magma and more gradual release of gas pressure in small discrete explosions (= strombolian activity).

Nevados de Chillán (Central Chile): A small eruption occurred at the volcano again yesterday, the first activity since the mild explosive activity on 7 February. Starting around noon, the volcano began to emit a steam plume of variable intensity, sometimes mixed with ash. The activity took place at one of the new craters that had formed in early February. According to SERNAGEOMIN, seismicity and other monitored parameters had shown little fluctuations during most of February, but then started to increase at the end of the month, possibly related to a slowly ascending body of magma. Yesterday’s new activity is likely the result of this and could be a precursor of more activity in the near to medium future.


Roundup of Global Volcanic Activity

Etna (Sicily, Italy): On November 1st a quite energetic seismo-volcanic event occurred most probably from the Bocca Nuova crater. Since that time there has been a change in the seismic tremor. During last weekend cloud cover prevented direct observations but today it was possible to observe very weak ash emissions most probably due to the activity inside the Voragine crater.


Roundup of Global Volcanic Activity

Aso (Kyushu): Activity has been low during the past days, with only intense steaming and dilute ash emissions from the Nakadake crater. Incandescence continues to be visible from the main vent, suggesting magma remains close to the surface.

Sangeang Api (Indonesia): A thermal hot spot of moderate intensity from the volcano’s summit continues to be visible on satellite data, suggesting some weak activity continues there. A steam plume can be seen rising from the volcano’s summit where a small lava dome might be growing.

Ubinas (Peru): A series of small explosions occurred today, producing ash plumes that rose up to approx. 700 m above the crater and drifted northeast.

Piton de la Fournaise (La Réunion): A new eruption started at the volcano this evening. Following a brief seismic crisis that triggered an eruption alarm, an eruptive fissure opened south of Dolomieu crater at 18:50 local time. It is producing impressive lava fountains and a branching lava flow.


Roundup of Global Volcanic Activity

Karymsky (Kamchatka): An ash plume from an explosion produced an ash plume that rose to 14,000 ft (4.2 km) altitude and drifted north this morning. The volcano continues to produce intermittent strombolian- to vulcanian-type explosive eruptions.

Chirinkotan (Northern Kuriles): Ash emissions were recorded on satellite imagery on 26 July, producing a plume that rose to 15,000 ft (4.5 km) altitude and drifted NW. During yesterday and today, the plume dissipated and no new emissions were detected (VAAC Tokyo).

Akan (Hokkaido): A swarm of shallow volcanic earthquakes under the Ponmachineshiri crater of Mt Meakan volcano has been occurring since yesterday. This event triggered the Japanese Meteorological Agency (JMA) to raise the volcanic alert status to 2 (eruption alert, on a scale of 1-5) today. The swarm follows a gradual increase in seismicity under the volcano noted since April this year. JMA thinks the most likely outcome is a very small (phreatic) eruption in the near future and recommends not to approach the crater within 500 m.

Raung (East Java): The eruption, now over 4 weeks old, continues with no significant changes. Strong lava effusion inside the summit caldera is accompanied by near-constant ash emissions rising 1-2 km and drifting up to 100-200 km in mostly westerly directions.

Dukono (Halmahera): Strong ash emissions continue at the volcano. VAAC Darwin reported an ash plume extending 25 km north of the volcano yesterday.


Roundup of Global Volcanic Activity

Nishino-shima (Volcano Islands, Japan): The eruption on the island continues with apparently relatively steady lava effusion that feeds active flows reaching and enlarging the SE corner of the island, which has now 2.7 square kilometer of surface. Mild strombolian activity and strong degassing occurs at the main vent, where a nice cinder cone has grown. The lava mostly flows through tubes, where it is hidden, to reach the active lava delta on the SE tip of the island. A smaller part seems also to feed/inflate inland surface lava flows in an area NE of the cone.

Sinabung (Sumatra, Indonesia): A series of larger pyroclastic flows occurred yesterday, reaching lengths of up to 4.5 km and producing ash plumes that rose up to approx. 4 km. Most likely, the now relatively large dome is currently again a phase of increased destabilization and more of such dangerous pyroclastic flows (hot block and ash flows) can be expected.

Sakurajima (Kyushu, Japan): The volcano remains highly active, producing regularly 5-10 or even more vulanian-type explosions on a daily basis. A few hours ago, JMA recorded the 650th this year alone.

Zhupanovsky (Kamchatka, Russia): A small ash emission from the volcano was reported on Saturday. Based on satellite imagery, an ash plume rose to 24,000 ft (7.2 km) altitude and drifted north (Tokyo VAAC).

Asama (Honshu): Weak activity continues from the volcano’s summit crater. Small ash emissions, intense degassing as well as weak incandescence from the volcano’s crater have been observed during the past days.


Roundup of Global Volcanic Activity

Kuchinoerabu-jima (Ryukyu Islands): Two people have been reported injured, presumably burnt by pyroclastic surge, and were flown to a hospital in Yakushima island. So far, it is not clear whether the eruption is a large-scale phreatic (steam-explosion driven) event or caused by new magma. Ash analysis should bring light into this soon.

A powerful vulcanian explosion occurred this morning at 11:02 am local time at the volcano. The eruption – a both vertical and partially lateral massive explosion, occurred with apparently little warning from the Shintake vent and produced large pyroclastic flows by column collapse. A tall mushroom ash plume quickly rose to approx. 12 km altitude (36,000 ft). JMA raised the alert level to the highest (5 out of 5) and authorities ordered immediate evacuation of the 130 inhabitants. Preliminary reports say that no fatalities or significant damage occurred, although this seems almost too good to be true, judging from the view of a massive pyroclastic flow that swept down to the coast near the port of the small island.

Sakurajima (Kyushu, Japan): After having been comparably calm the past days, the volcano started a series of strong explosions this morning. Ash plumes rose to reported 14,20,000 ft altitude. The eruptions were followed by long phases of mild to moderate, continuous jets of ash.

Wolf (Galápagos Islands, Ecuador): During the evening of 27 May (local time), the lava flow entered the sea on the southeast shore of the northern part of Isabela island.


Roundup of Global Volcanic Activity

Calbuco (Southern Chile and Argentina): A major explosive eruption started at the volcano yesterday afternoon (20:45 GMT). VAAC Buenos Aires reported an ash plume to 30,000 ft (10 km) altitude. The eruption started at 18:05 local time and came with little warning signs apparently. Residents in a radius of 20 km around the volcano are being evacuated. As the ash plume quickly drifted northeast towards Argentinia’s Bariloche region, the Bariloche airport was closed. Aviation colour code was raised to red as a warning to aircraft to avoid the area.


Roundup of Global Volcanic Activity

Aso (Kyushu): Mild strombolian activity with low-level ash emissions continue from the Nakadake crater.

Sakurajima (Kyushu, Japan): The volcano has been very active recently. Vulcanian-type explosions have been frequent (2-8 per day) and often relatively large.

On 15 April, at least 8 explosions occurred, the largest of which produced ash plumes that rose to 15,000 ft (4.5 km altitude), i.e. 3.5 km above the volcano’s summit.

Nevado del Ruiz (Colombia): Activity at the volcano has increased during the past week. Accompanied by elevated seismic activity, ash emissions have been occurring since 14 April. The strongest phase of activity was on 19 April, when ash plumes rose to estimated 900 meters above the summit.

The Ingeominas volcano observatory in Manizales reported a change in seismicity detected since 12 April, when an increase in volcanic-tectonic (rock-fracturing) signals was detected, signs of pressurization and possible magma intrusion at depth.