Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 17 May – 23 May 2017

Manam | Papua New Guinea : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 18-20 May ash plumes from Manam rose 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted W and WNW.

Nishinoshima | Japan : The Japan Coast Guard reported that during an overflight of Nishinoshima during 1300-1345 on 2 May observers noted frequent (every 40-60 seconds) Strombolian explosions at a new pyroclastic cone in the crater. Ash plumes rose 500 m. Two lava flows originating from the N part of the cone traveled 180 m SW and 170 m W, and entered the ocean. The island continued to grow and was estimated to be 2 km E to W and about 1.9 km N to S, with an area of 2.75 square kilometers (it was 2.68 square kilometers on 15 September 2016).

Poas | Costa Rica : OVSICORI-UNA reported that tremor levels at Poás were at low-to-moderate levels during 17-21 May and at higher levels during 22-23 May. Low-amplitude long-period earthquakes were recorded on 19 May, and some low-frequency and volcano-tectonic events were detected during 21-22 May. Plumes consisted mainly of gas and water vapor, but sometimes included solid material, and rose no more than 1 km above the vent.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 13-14 May a series of explosions at Sheveluch generated ash plumes that rose 4.5-5 km (14,800-16,400 ft) a.s.l. and drifted SW and SE. Powerful explosions on 16 May generated ash plumes that rose as high as 11 km (36,100 ft) a.s.l. and drifted about 150 km ENE. Pyroclastic flows descended the S flank. Two explosions were detected on 18 May. Ash plumes during 16-19 May drifted 400 km ENE. The Aviation colour Code (ACC) remained at Orange during 13-19 May, except for a few hours on 16 May when the strong explosions prompted KVERT to raise the ACC to Red.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 10 May – 16 May 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 10-14 May ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SW, W, NW, and E.

Bezymianny | Central Kamchatka (Russia) : KVERT reported gas-and-steam activity at Bezymianny during 5-12 May, and a thermal anomaly identified in satellite images during 5 and 8-9 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that an increase in seismic and infrasound activity from Bogoslof was detected from stations on nearby islands starting at 2232 on 16 May, suggesting the beginning of an explosive eruption. The Aviation colour Code (ACC) was raised to Orange and the Volcano Alert Level (VAL) was raised to Watch. A pilot reported an ash plume rising as high as 10.4 km (34,000 ft) a.s.l., and the Worldwide Lightning Location Network detected lightning associated with the cloud. The ACC was raised to Red and the VAL was raised to Warning. The eruption lasted about 73 minutes.

Cleveland | Chuginadak Island (USA) : AVO reported that no significant volcanic activity at Cleveland was detected in seismic, infrasound, or satellite data during 10-16 May. The webcam recorded some gas plumes during 13-14 May. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Colima | Mexico : On 12 May the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 26 high-frequency events, 21 long-period events, 2.5 hours of tremor, 12 landslides, and three low-intensity explosions.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 10-16 May ash plumes from Dukono rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted in multiple directions as far as 150 km.

Ebeko | Paramushir Island (Russia) : KVERT reported that an ash plume from Ebeko was identified in satellite images drifting about 50 km NE on 7 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu | Halmahera (Indonesia) : Based on analyses of satellite imagery and information from PVMBG, the Darwin VAAC reported that during 10-11 May ash plumes from Ibu rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E and SW. An ash plume on 16 May rose to 1.5 km (5,000 ft) a.s.l.

Karangetang | Siau Island (Indonesia) : Based on analyses of satellite imagery, wind data, and ground-based visual observations, the Darwin VAAC reported that on 10 May a gas-and-steam plume, possibly containing ash, rose from Karangetang to an altitude of 3.6 km (12,000 ft) a.s.l. and drifted over 35 km SE.

Kilauea | Hawaiian Islands (USA) : HVO reported that the lava delta at Kamokuna (the ocean entry area at Kilauea), which had been growing since late March, collapsed on 3 May. Two large cracks parallel to the coast were visible on 27 April, suggesting instability. Between 0935 and 0940 on 3 May a large steam plume appeared in the middle of the lava delta in the area of large cracks. Weak fountaining or spattering likely occurred initially, because new tephra deposits were visible in the steaming area; that activity ended by 0940. Images acquired over the next 25 minutes showed a progressively weaker steam plume, and a subsiding delta. Photos of the ocean entry taken on 7 May showed multiple streams of lava flowing into the ocean. During 10-16 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Surface lava flows were active above and near the pali.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that ash plumes from Klyuchevskoy were identified in satellite images drifting 270 km SE and NW during 5-6 and 10-11 May, respectively. A weak thermal anomaly was noted on 5 and 10 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) :Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 10-14 May ash plumes from Langila drifted N, NW, and S at altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 9-15 May seismicity at Nevado del Ruiz continued to indicate unrest; the number and magnitude of events were higher compared to the previous week. Significant amounts of water vapor and gas continued to be emitted. Gas, steam, and ash plumes rose 1.7 km above the crater rim on 12 May and drifted NW and SW. According to the Washington VAAC the Bogota MWO reported an ash emission on 13 May. The Alert Level remained at III (Yellow; the second lowest level on a four-colour scale).

Reventador | Ecuador : During 10-16 May IG reported a high level of seismic activity at Reventador including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Steam, gas, and ash plumes rose as high as 700 m above the crater rim during 10-12 May. Crater glow was noted during 11-12 May.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 8-14 May explosive activity at Sabancaya slightly decreased from the previous week, with an average of 38 explosions detected per day. The number of long-period events continued to increase, while hybrid events were sporadic. Gas-and-ash plumes rose as high as 4.2 km above the crater rim and drifted more than 40 km NE, E, and SE.

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 10-16 May ash plumes from Sinabung rose to altitudes of 3-4.9 km (10,000-16,000 ft) a.s.l. and drifted E and NE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 10 May plumes from Suwanosejima rose to an altitudes of 2.7 km (9,000 ft) a.s.l. and drifted E.

Turrialba | Costa Rica : OVSICORI-UNA reported an explosion at Turrialba on 10 May, followed by weak and passive ash emissions during 10-11 May. Several long-period earthquakes were recorded, and inflation continued. Gas measurements indicated a sulfur dioxide flux of 1,000 tons/day, and a high carbon dioxide/sulfur dioxide ratio. An event at 0900 on 12 May generated a plume, though poor visibility prevented a height estimate. An event at 0730 on 14 May generated a plume that rose 500 m above the crater rim and drifted N. Low-amplitude tremor was detected during 15-16 May, and a discontinuous ash plume rose no more than 500 m and drifted N and NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 10 May – 16 May 2017

Aira | Kyushu (Japan) : According to JMA, fieldwork at Aira Caldera’s Sakurajima volcano revealed that the sulfur dioxide flux rose from 300 tons on 28 April to 1,700 tons on 8 May; the last time sulfur dioxide flux was above 1,000 tons was 23 June 2015. At 1312 on 12 May an explosion at Showa Crater generated a plume that rose 700 m above the crater rim, into a weather cloud. Four events were detected during 13-15 May; one of the events, an explosion at Showa Crater on 14 May, produced a plume that rose 2.3 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Fuego | Guatemala : INSIVUMEH reported that during 9-16 May explosions at Fuego generated ash plumes that rose as high as 950 m above the crater rim and drifted 7-12 km W, SW, S, and E. Ashfall was reported in San Pedro Yepocapa (8 km N), Morelia (9 km SW), Santa Sofía (12 km SW), and Panimache I and II (8 km SW) during 9-12 May. On 14 May a hot lahar descended the Río Ceniza (SSW) and Santa Teresa (W) drainages, carrying blocks 2 m in diameter, branches, and tree trunks. Sounds from colliding blocks were audible more than 1 km away, and steam plumes rose from the lahar. During 14-16 May avalanches descended the Ceniza and Las Lajas (SE) drainages, and gas emissions rose from pyroclastic-flow deposits in the ravines.

Manam | Papua New Guinea : RVO reported that during 11-14 May Manam’s Main Crater was quiet, emitting only dense white vapor. On 12 May Southern Crater emitted dark gray ash plumes, and on 13 May only whitish-blue vapor emissions were observed. During 0100-0400 on 14 May roaring and explosions were heard in Bogia Station; incandescent lava fragments were ejected from the crater. Seismicity was low (RSAM averaged 50 units) and dominated by low-frequency events during 11-12 May. RSAM increased on 13 May, peaking at 450 units at 2330, and then dropped to 110 units at 0500 on 14 May. RSAM increased to 250 by 0800 and remained at that level through 14 May. The Alert Level remained at Stage 2.

Masaya | Nicaragua : The Washington VAAC reported that on 13 May a west-drifting ash emission from Masaya was identified in satellite images and observed by a pilot.

Poas | Costa Rica : OVSICORI-UNA noted ash emissions at Poás on 10 May. Gas emissions were measured by an instrument mounted on a drone, revealing a gas plume rich in sulfur dioxide and low in carbon dioxide. During 10-11 May tremor amplitude was variable but low, and several volcano-tectonic events were detected. During 11-13 May tremor was constant, and volcano-tectonic and long-period events were detected; the seismicity possibly indicated small eruptions. Deformation was high, with vertical inflation of 3 cm since February.

Sheveluch | Central Kamchatka (Russia) : KVERT reported continuing lava-dome extrusion at Sheveluch’s N flank during 5-11 May. A daily thermal anomaly over the dome was identified in satellite images, and ash plumes drifted 90 km NNE and NW on 8 and 10 May. Strong explosions on 12 May generated ash plumes identified in satellite images that rose 9-10 km (29,500-32,800 ft) a.s.l., spread 70 km wide, and drifted 115 km NW. The Aviation Color Code was raised to Red. A few hours later satellite images showed a thermal anomaly and no ash emissions; the Aviation Color Code was lowered to Orange. Explosions on 16 May generated ash plumes that rose 8-9 km (26,200-29,500 ft) a.s.l., prompting KVERT to again raise the Aviation Color Code to Red. Pyroclastic flows descended the flanks and produced ash plumes that rose 3.5-4 km (11,500-13,100 ft) a.s.l. and drifted NE. Within a few hours satellite images showed a thermal anomaly and no ash emissions; the Aviation Color Code was lowered to Orange. An ash cloud with the dimensions of 51 x 43 km was still visible in satellite images, moving E.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 3 May – 9 May 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 7-9 May ash plumes from Bagana rose to altitudes of 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted over 110 km SE, SSE, and S.

Bezymianny | Central Kamchatka (Russia) : KVERT reported gas-and-steam activity at Bezymianny during 28 April-5 May, and a daily thermal anomaly identified in satellite images. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 3-6 May ash plumes from Dukono rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted W, E, 90 km ESE, and 185 km NE.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 28 April-5 May satellite images of Ebeko showed quiet conditions or weather cloud cover. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale). Based on satellite observations, the Tokyo VAAC reported that during 8-9 May plumes rose to altitudes of 2.4-2.7 km (8,000-9,000 ft) a.s.l. and drifted S and NE. The cause of the plumes was unclear, and weather clouds hindered observations.

Kambalny | Southern Kamchatka (Russia) : On 5 May KVERT reported that conditions at Kambalny were quiet the previous week. The Aviation colour Code was lowered to Yellow.

Kanlaon | Philippines : On 5 May PHIVOLCS reported that since the last phreatic eruption at Kanlaon, which occurred on 15 June 2016, there has been a general decline in activity: seismicity was at baseline levels, no significant deformation had been detected since August 2016, sulfur dioxide emissions were low, and no steaming had been observed since 29 September 2016. The Alert Level was lowered to 0 (on a scale of 0-5), though the public was warned to not enter the 4-km-radius Permanent Danger Zone (PDZ).

Kilauea | Hawaiian Islands (USA) : During 3-9 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna adding to the growing delta. Surface lava flows were active above the pali.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly was identified in satellite images over Klyuchevskoy during 30 April-1 May, and an ash plume drifted about 52 km E on 1 May. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 3 May a webcam recorded a puff rising from Nevados de Chillán and dissipating rapidly.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 1-7 May explosive activity at Sabancaya increased, with an average of 41 explosions detected per day. The number of long-period and hybrid events also increased. Ash plumes rose as high as 3.5 km above the crater rim and drifted more than 40 km NE and E. Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported that during 3-9 May sporadic gas-and-ash puffs rose to altitudes of 7-8.2 km (23,000-27,000 ft) a.s.l. and drifted SE, E, and NE.

San Miguel | El Salvador : SNET reported that during 28 April-5 May RSAM values at San Miguel had decreased and fluctuated between 50 and 173 units (typical background levels average 50 units). Sulfur dioxide flux was also lower, though changing winds may have affected readings.

Santa Maria | Guatemala : INSIVUMEH reported that 10-12 explosions at Santa María’s Santiaguito lava-dome complex were detected by the seismic network during 4-5 May. Beginning at 2145 on 6 May a strong lahar, 30 m wide and 2.5 m deep, descended the Cabello de Ángel drainage, a tributary of the Nimá I river drainage on Santa María’s S flank, carrying branches, tree trunks, and blocks up to 2 m in diameter.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 28 April-5 May lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. A thermal anomaly at the dome was identified daily in satellite images. Ash plumes drifted more than 730 km SE, SW, and NW during 27 April-3 May; explosions on 30 April generated ash plumes that rose to an altitude of 9.1 km (30,000 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 3-9 May ash plumes from Sinabung rose to altitudes of 3-5.5 km (10,000-18,000 ft) a.s.l. and drifted in multiple directions.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 8 May plumes from Suwanosejima rose to altitudes of 1-2.1 km (3,000-7,000 ft) a.s.l. and drifted N and SW.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 1700 on 5 May generated a weak ash plume that rose 500 m above the crater and drifted SW. Two short-amplitude events occurred at 1702 and 1820 though there was no confirmation if they had corresponded to eruptions. During 5-7 May volcano-tectonic and long-period earthquakes were detected, as well as variable-amplitude tremor. At 1250 on 6 May an event produced a plume that rose 300 m and drifted W. Between 1250 and 1730 a passive ash emission rose no higher than 1 km. Another passive ash emission rose about 500 m at 1000 on 7 May and drifted WNW. At 0902 on 9 May an event generated an ash plume that rose 500 m and drifted NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 3 May – 9 May 2017

Aira | Kyushu (Japan) : JMA reported that nine events at Showa Crater (at Aira Caldera’s Sakurajima volcano) were detected during 1-8 May. One of the events was explosive, generating an ash plume that rose 4 km above the crater rim and ejecting material 300-500 m from the crater. Ashfall was reported in the cities of Kagoshima (3 km NW), Hioki (25 km WNW), and Ichikikushikino (40 km NW). Nighttime crater incandescence was noted on 2 and 5 May. An event at 1213 on 5 May at Minamidake summit crater produced a plume that rose 500 m above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Fuego | Guatemala : In a special report INSIVUMEH reported that a new phase of activity (the fourth of the year) at Fuego began on 5 May and was the strongest activity recorded since 2012. Strong explosions, sometimes producing shock waves, generated dense ash plumes that rose 1.3 km above the crater and drifted more than 50 km S, SW, and W. Ashfall was reported in many areas downwind, including San Pedro Yepocapa (8 km N), Morelia (9 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), finca Palo Verde, Santa Lucia Cotzumalguapa (23 km SW), Siquinala, San Andrés Osuna, Chuchu, and La Reunión. Lava flows traveled 2 km down the Santa Teresa (W) drainage and 3 km down the Las Lajas drainage. Pyroclastic flows descended the Trinidad (S), Las Lajas (SE), Ceniza (S), and Santa Teresa drainages. Residents of Sangre de Cristo (8 km WSW) were evacuated. Explosions were not reported that next day and the lava flows may have stopped advancing. According to a news article, about 300 people had been evacuated from Panimache (8 km SW). During 7-8 May lower-energy explosions generated ash plumes that rose as high as 750 m above the crater and drifted 8-20 km W and SW. Gases were observed rising from pyroclastic flow deposits in the ravines.

Manam | Papua New Guinea : RVO reported that another phase of Strombolian activity at Manam’s Southern Crater began around 1700 on 4 May when RSAM values increased to 100-150. A sharp increase in values was detected at 0330 on 5 May, though the highest RSAM value (1,400) occurred between 0500 and 0600. RSAM dropped rapidly to 200 by around 0700, and then by 1400 RSAM values were around 50. Strombolian activity on 5 May was characterized by loud roaring and rumbling, ejected incandescent material, and ash and scoria fall; some phases of very strong activity occurred during 0530-0600. A lava flow traveled down the SW valley and stopped at 600 m elevation. Minor amounts of ash fell in all parts of the island including Warisi (E), Dugulaba (S), and Boda and Baliab (NW). Though weather clouds prevented visual observations of Manam during 6-8 May, activity in general was very low; noises and crater incandescence were absent, and seismicity was lower than it had been for many weeks (RSAM

Poas | Costa Rica : OVSICORI-UNA reported that an eruption at Poás was detected at 1724 on 6 May though poor visibility prevented visual confirmation of the event. During 6-7 May volcano-tectonic and long-period earthquakes were detected, as well as moderate-amplitude tremor.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 26 April-2 May 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 26-28 April ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted N and NE.

Bezymianny | Central Kamchatka (Russia) : KVERT reported gas-and-steam activity at Bezymianny during 21-28 April, and a daily thermal anomaly identified in satellite images. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Cleveland | Chuginadak Island (USA) : AVO reported that satellite images of Cleveland acquired during 28 April-2 May showed that the lava dome in the summit crater had widened and grown taller. AVO further noted that dome extrusion had occurred with little to no detectable seismicity. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Colima | Mexico : On 28 April the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 34 high-frequency events, 26 long-period events, 2.5 hours of tremor, 8 landslides, and one low-intensity explosion. During fieldwork on the N part of the volcano, scientists found deposits of ballistics within 1.9 km of the crater. A higher density of deposits was found to the NNE, and deposits from pyroclastic flows were noted as far as 1.5 and 1.7 km N of the crater.

Dukono | Halmahera (Indonesia) | 1.693°N, 127.894°E | Elevation 1229 m

Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 26 April-2 May ash plumes from Dukono rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted W and 280 km E.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 23-26 April several explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 2.1 km (6,900 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 25 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that at 1820 on 26 April lava began effusing from a vent on the S side of Etna’s New Southeast Crater (NSEC), traveling to the base of the cone. Around 2220 Strombolian activity ejected material from the vent and the lava flow headed towards the Valle del Bove. A lava flow on the N side of the cone began at 0220 on 27 April and traveled NE towards the Valle del Leone. Ash emissions were visible at 0320. Strombolian activity began to diminish around 1230 and eventually ceased. The lava flows advanced until around 1600; phreato-magmatic explosions occurred in areas where the NE flow interacted with snow.

Fuego | Guatemala | 14.473°N, 90.88°W | Elevation 3763 m

INSIVUMEH reported that beginning at 1700 on 24 April a hot lahar descended Fuego’s Río Ceniza (SSW) drainage, carrying blocks 2 m in diameter, branches, and tree trunks. The lahar was heard up to 1 km away. During 29 April-2 May explosions generated ash plumes that rose as high as 1.1 km above the crater rim and drifted as far as15 km W and SW. Some of the explosions produced shock waves felt within a 10-km radius. Ash fell in Sangre de Cristo (8 km WSW) and possibly other areas. Incandescent material was ejected as high as 200 m above the crater rim.

Kick ’em Jenny | North of Grenada : The University of the West Indies (UWI) Seismic Research Centre (SRC) reported that seismic activity at Kick ’em Jenny increased on 29 April. A high-amplitude signal lasting 25 seconds was recorded by stations on Grenada and Montserrat. This signal followed an increase in the number of background events associated with the volcano. The report reminded the public of the 5-km maritime exclusion zone.

Kilauea | Hawaiian Islands (USA) : During 26 April-2 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. A growing lava delta is building where the lava enters the water; a small collapse of the delta on 27 April was indicated by the presence of a large dark plume. Surface lava flows were active above the pali.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly was identified in satellite images over Klyuchevskoy daily during 21-28 April. Ash plumes drifted about 125 km SW during 22-23 and 25 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 25 April-2 May seismicity at Nevado del Ruiz continued to indicate unrest; the number and magnitude of events were higher compared to the previous week. Significant amounts of water vapor and gas continued to be emitted. Gas, steam, and ash plumes rose 1.2 km above the crater rim on 26 April and drifted NW and SW. A low-energy thermal anomaly was identified on 28 April. The Alert Level remained at III (Yellow; the second lowest level on a four-colour scale).

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 29 April a webcam recorded a puff rising from Nevados de Chillán and dissipating rapidly

Popocatepetl | Mexico : Each day during 25 April-2 May CENAPRED reported 26-109 steam and gas emissions from Popocatépetl, sometimes containing ash, and crater incandescence at night or in the early morning. Around seven explosions were detected almost each day, with as many as 15 counted during 26-27 April (from mid-morning to mid-morning). Explosions generated plumes that consisted of water vapor and gas, with low ash content, and during 26-27 April they ejected tephra as far as 100 m NE of the crater. The Alert Level remained at Yellow, Phase Two.

Reventador | Ecuador : During 25 April-2 May IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Steam, gas, and ash plumes rose around 500 m above the crater rim and drifted W and SW on most days. On 25 April incandescent blocks were observed rolling 800 m down the SW and SE flanks. Crater glow was noted through 28 April. Weather clouds prevented visual observations during 29 April-1 May.

Rinjani | Lombok Island (Indonesia) : PVMBG reported an increase of volcanic tremor at Rinjani on 28 April, with a pattern similar to the one recorded just prior to the 27 September 2016 eruption. The Alert Level remained at 2 (on a scale of 1-4); the public was warned not to approach the crater within a 1.5-km radius.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 24-30 April seismicity at Sabancaya slightly declined compared to the previous week, with an average of 33 explosions recorded per day. Ash plumes rose as high as 3.2 km above the crater rim and drifted more than 40 km SE. Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs during 25 April-2 May. Strong ash plumes rose to an altitude of 7.9 km (26,000 ft) a.s.l. (or 2.4 km above the crater rim) and drifted SE on 26 and 28 April.

San Miguel | El Salvador : SNET reported that during 27-28 April RSAM values at San Miguel fluctuated between 106 and 176 units (typical background levels average 50 units). At 1532 on 27 April a strong gas plume rose 1.2 km above the crater rim.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 21-28 April lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. A thermal anomaly over the dome was identified in satellite images daily. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 26-30 April and 2 May ash plumes from Sinabung rose to altitudes of 3.3-4.6 km (11,000-15,000 ft) a.s.l. and drifted in multiple directions.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 26 April-2 May 2017

Aira | Kyushu (Japan) : JMA reported that there were less than 10 small events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 26-27 April, the first eruptions at that crater since 26 July 2016. During 28 April-1 May there were 16 events, of which two were explosive, ejecting tephra up to 800 m from the crater. One of the explosive events, at 1101 on 28 April, generated an ash plume that rose 3.2 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Ibu | Halmahera (Indonesia) : Based on PVMBG observations and satellite images the Darwin VAAC reported that during 26-27 and 29-30 April ash plumes from Ibu rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E, NE, and N.

Kambalny | Southern Kamchatka (Russia) : KVERT reported that moderate levels of activity at Kambalny continued during 21-28 April. The Aviation colour Code remained at Orange.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 26 April and 2 May ash plumes from Langila drifted E and NE at an altitude of 2.1 km (7,000 ft) a.s.l.

Manam | Papua New Guinea : RVO reported that periods of Strombolian activity at Manam’s Southern Crater were observed during 24-30 April, and roaring and rumbling was heard. Explosions were also heard and sometimes followed by detectable shock waves. Most incandescent tephra fell back into the crater but some were deposited in the SW and SE valleys. Strombolian activity declined for a period on 25 April, and only dense gray ash plumes were seen rising from the crater. Activity was lower during 26-27 April. Strombolian explosions returned on 28 April; some of the explosions were strong and rattled nearby houses. One strong explosion and banging was heard at the Bogia Government Station. A period of moderate to moderately-high Strombolian activity was detected during 0200-0330 on 30 April. A small pyroclastic flow traveled down the SW valley, stopping around 200 m a.s.l. Scoria (up to 40 mm in diameter) and ash fell on the E side of the island in Abaria and Boakure.

Poas | Costa Rica : OVSICORI-UNA reported that during 30 April-1 May seismicity at Poás was characterized by volcano-tectonic events, long-period events, and low-amplitude tremor. A larger event was recorded at 0621 on 1 May, though there was no other confirmation of an eruption.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 19 April – 25 April 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 16-17 April ash plumes from Bagana rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, SE, and S. Plumes drifted 55-85 km during 19 and 23-24 April.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 14-21 April lava continued to advance down the NW flank of Bezymianny’s lava dome. A thermal anomaly was identified in satellite images during 14-17 April. The Aviation colour Code remained at Orange.

Bogoslof | Fox Islands (USA) : On 19 April AVO noted that no new volcanic activity at Bogoslof had been detected in satellite, seismic, or infrasound data since a short-lived increase in seismicity on 15 April; AVO lowered the Aviation colour Code to Yellow and the Volcano Alert Level to Advisory.

Cleveland | Chuginadak Island (USA) : AVO reported that recent satellite images of Cleveland revealed that a lava dome has been extruded in the summit crater, with growth likely beginning after the last explosion on 31 March. The Aviation colour Code was raised to Orange and the Volcano Alert Level was raised to Watch.

Slightly elevated surface temperatures were identified in satellite images over the past couple of weeks. The new dome was first visible in images on 15 April, with the presence of a small (less than 10 m diameter) mound deep in the crater. By 23 April this mound had grown to 45 m in diameter. Dome growth had occurred with no detectable seismicity.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 19-25 April ash plumes from Dukono rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted NE, E, and SE.

Ebeko | Paramushir Island (Russia) : KVERT reported that on 14, 16, and 19 April several explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 3.2 km (10,500 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 18 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 19-25 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. A growing lava delta is building where the lava enters the water. Surface lava flows were active above the pali.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly was detected over Klyuchevskoy during 14-17 and 23 April. A steam-and-gas plume that rose to 5 km (16,400 ft) a.s.l. and drifted 125 km SW on 23 April contained some ash, prompting KVERT to raise the Aviation colour Code to Orange. On 24 April satellite images showed an ash plume drifting 72 km SW at an altitude of 7 km (23,000 ft) a.s.l. On 25 April KVERT noted that activity had significantly decreased and only steam-and-gas emissions were observed. The Aviation colour Code was lowered to Yellow. On 25 April ash was again present in a plume; KVERT raised the Aviation colour Code to Orange. The plume rose 3-4 km (9,800-13,100 ft) a.s.l. and drifted 60 km SW.

Sabancaya | Peru : Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs from Sabancaya during 18-25 April, sometimes rising as high as 8.2 km (25,000 ft) a.s.l.; clouds sometimes hindered observations of the volcano.

San Miguel | El Salvador : In a special report from 17 April, SNET reported an increase in seismicity and gas emissions from San Miguel in recent days. Earlier that day during 0620-0630 RSAM values spiked to 356, an increase over normal values around 50. During 18-21 and 23-24 April RSAM values fluctuated between 80 and over 300.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 15-21 April 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 thermal anomaly over the dome during 13-17 April, and an ash plume that drifted 95 km E on 15 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 20-22 and 24 April ash plumes from Sinabung rose to altitudes of 3.3-4.3 km (11,000-14,000 ft) a.s.l. and drifted SW and E.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 19 April – 25 April 2017

Ibu | Halmahera (Indonesia) : Based on PVMBG observations the Darwin VAAC reported that during 19-21 April ash plumes from Ibu rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted E and N.

Kambalny | Southern Kamchatka (Russia) : KVERT reported that moderate activity at Kambalny continued during 15-21 April. Observers in the South Kamchatka Sanctuary noted minor ashfall in the Kurilskoe Lake area on 19 April. The Aviation Colour Code remained at Orange.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 23-25 April ash plumes from Langila rose to an altitude of 2.1 km (7,000 ft) a.s.l., and drifted S and 55 km SE.

Manam | Papua New Guinea : RVO reported that activity at Manam decreased on 18 April and continued at low levels through 21 April. Roaring noises came from both Main and Southern craters. Both craters were incandescent, but only Southern Crater ejected incandescent tephra, which became intense during 0900-1100 on 20 April. Pale gray-to-brown plumes with a minor amounts of ash rose from both craters and drifted SE. RSAM values were about 75-150 units, but between about midnight and 0100 on 22 April they began to rise. RSAM values were 600 at 0500, and then they fluctuated between 400 and 1,400 units at least through 1400, the time of the report posting. According to a news article from 25 April the Alert Level was raised to Stage 3, and an official on the island noted that women and children have begun to be evacuated to Bogia on the mainland.

Nishinoshima | Japan : Satellite images of Nishinoshima acquired on 19 April and processed by NASA’s Earth Observatory showed an area of hot lava in the crater. According to a news article, observers aboard a plane passing the volcano on 21 April noted intense activity in the crater. Bombs were ejected as high as 100 m above the crater and incandescent rocks rolled down the flanks, reaching the sea. The report noted brown plumes rising from the crater and lava effusing from an area near the top of the vent.

Poas | Costa Rica : OVSICORI-UNA reported that on 20 April a dense water vapor plume rose from a vent in the newly-forming pyroclastic cone at the site of the old dome in the hot lake at Poás. Gas flux increased from 1,000 tons/day (t/d) on 13 April to 2,500 t/d on 20 April. During 20-22 April Strombolian activity ejected tephra that fell around the vent within a 300-m radius. Gas-and-ash plumes rose 200 m above the vent. The Red Cross of Grecia reported ashfall in Alajuela, Fraijanes, San Miguel, Carbonal, Cajón, San Francisco, San Roque, and San Juan Norte de Poás. Events at 1316 and 1603 on 22 April produced plumes of unknown height. Several more eruptive events were recorded that day; an event at 2212 was very intense, ejecting bombs large distances. An event at 1215 on 23 April generated a plume of unknown height.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 12 April – 18 April 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 16-17 April ash plumes from Bagana rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, SE, and S.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 7-14 April lava continued to advance down the NW flank of Bezymianny’s lava dome. A thermal anomaly was identified in satellite images daily. The Aviation colour Code remained at Orange.

Bogoslof | Fox Islands (USA) : Increased seismicity at Bogoslof was recorded by stations on nearby islands starting around 1501 on 15 April, prompting AVO to raise the Aviation colour Code to Orange and the Volcano Alert Level to Watch. The seismic activity subsided a few hours later; there was no evidence of renewed eruptive activity from infrasound, lightning, or satellite data during 15-18 April.

Colima | Mexico : On 14 April the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 48 high-frequency events, 30 long-period events, 3.3 hours of tremor, 10 landslides, and two explosions.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 12-18 April ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted S, SW, W, and N.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 7-14 April several explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 2.6 km (8,500 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 12 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna | Sicily (Italy) : INGV reported that the effusive eruption from a vent in the saddle between Etna’s Southeast Crater (SEC) – New Southeast Crater (NSEC) cone complex ended during 8-9 April. During 10-11 April lava effused from a vent located at the S base of the SEC. The lava flow traveled SE and flowed several hundred meters down the W wall of the Valle del Bove. In the evening of 13 April short-lived explosive activity occurred at a vent at the S flank of the SEC cone at about 3,200 m elevation. That vent and another at 3,150 m elevation produced lava flows for a few hours. Lava also effused from the vent at the S base of SEC, 3,010 m elevation, during 13-14 April, traveling SE and down the W wall of the Valle del Bove on top of the flows from 10-11 April.

Kilauea | Hawaiian Islands (USA) : During 12-18 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. A growing lava delta is building where the lava enters the water. Surface lava flows were active above the pali.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that at 1822 on 14 April a seismic event at Nevado del Ruiz was recorded, associated with a gas-and-ash emission recorded by the webcam that rose almost 1.2 km above the crater. The Alert Level remained at III (Yellow; the second lowest level on a four-colour scale).

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 17 April a webcam recorded the ejection of incandescent material from Nevados de Chillán, and a possible ash plume that rose to 3.7 km (12,000 ft) a.s.l.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 10-16 April seismicity at Sabancaya increased compared to the previous week, with an average of 37 explosions recorded per day. Ash plumes rose as high as 3 km above the crater rim (13 April) and drifted more than 40 km NW and SE. The Buenos Aires VAAC reported that on 17 April ash plumes rose to an altitude of 7.9 km (26,000 ft) a.s.l. and drifted SE. The next day ash emissions were recorded by the webcam. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 7-14 April 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, and an ash plume that drifted 82 km SW on 10 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 12-15 and 17 April ash plumes from Sinabung rose to altitudes of 3-4.6 km (10,000-15,000 ft) a.s.l. and drifted W, SW, and E.

Turrialba | Costa Rica : OVSICORI-UNA reported a passive ash emission from Turrialba on 16 April. An event at 0751 on 17 April generated a plume with minor ash content that rose 500 m above the crater and drifted SW. A diffuse plume consisting of gas and sometimes ash rose 1 km above the crater and drifted W on 18 April.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 12 April – 18 April 2017

Aira | Kyushu (Japan) : JMA reported that a very small eruption at Minamidake summit crater (at Aira Caldera’s Sakurajima volcano) occurred on 16 April. The Alert Level remained at 3 (on a 5-level scale).

Ibu | Halmahera (Indonesia) : Based on ground and satellite observations, PVMBG and the Darwin VAAC reported that during 12-13 and 17 April ash plumes from Ibu rose 1.5-1.8 km (4,900-5,900 ft) a.s.l. and drifted S and SW.

Kambalny | Southern Kamchatka (Russia) : KVERT reported that observers in the South Kamchatka Sanctuary noted an ash plume from Kambalny rising to an altitude of 7 km (23,000 ft) a.s.l. on 9 April. Ash plumes identified in satellite images drifted 50 km NE on 9 April and about 170 km SE the next day. The Aviation colour Code remained at Orange.

Manam | Papua New Guinea : RVO reported that incandescence from both Manam’s Southern Crater and Main Crater fluctuated in intensity during 1-15 April, and incandescent material was occasionally ejected from the craters. RSAM values averaged around 100. On 15 April RSAM values fluctuated, with a peak of 450 at 0600 and other peaks throughout the day, though with RSAM values not as high. RVO interpreted the high RSAM values as changes in seismicity from discrete low-frequency earthquakes, to sub-continuous volcanic tremor, and then to continuous volcanic tremor.

During 0300-0800 on 16 April RSAM values were high (peaking at 400); there were no reports of associated anomalous eruptive activity, though RVO noted communication problems. Based on RSAM data, a small-to-medium eruption began between 1400 and 1600 on 16 April. Seismicity was initially erratic, and peaked at about 0030 and 0100 on 17 April. A Dugulava village resident (S side of island) briefly viewed the eruption and reported that incandescent material was ejected from the crater and fell into the N and SW valleys. Rumbling and roaring was also heard. Activity decreased around 0600 and remained low until the next day. Strong Strombolian activity at Southern Crater was observed at about 1300 on 18 April, and roaring and rumbling was heard. Dense and dark ash clouds rose a few hundred meters above the crater rim and drifted NW. Two small pyroclastic flows descended the SE and SW valleys, terminating at about 1 km a.s.l. At about 1500 Strombolian activity subsided, coinciding with a very loud explosion. Activity fluctuated though was low until 2100, and then afterwards light-gray ash plumes rose above the crater. White-to-gray ash plumes rose above Main Crater during 17-18 April, and small ejections of material occurred about every five minutes.

Poas | Costa Rica : OVSICORI-UNA reported that a strong 40-minute phreatic eruption from an area in between the lava dome and the hot lake at Poás was recorded on 12 April starting at 1830. An eruption column consisting of water, altered rocks, sediments, and gases was produced; the height of the column could not be determined due to poor visibility. Ash fell around the crater and to the NW in Bajos del Toro. A water-level increase of 2 m in the Desague River, with headwaters at the S part of the crater, was noted. According to news articles the National Emergency Committee (CNE) evacuated residents living near the Desague River. The Poás Volcano National Park closed the next day.

At 1546 on 13 April an eight-minute-long eruption produced a plume that rose 500 m above the crater rim. The event rendered a webcam on the N rim inoperable. Events at 0758 (strong) and 1055 on 14 April generated plumes of an unknown height. A 10-minute-long event which began at 0810 on 15 April again produced a plume of unknown height. Frequent (2-3 events per hour) small short-lived phreatic eruptions were recorded by seismographs during 15-16 April. A plume that rose 500 m followed an eruption at 0946 on 16 April. Later that day, at 1350, an event generated a plume that rose 1 km. A news article reported that boulders as large as 2 m in diameter fell in an area 30 m away from a tourist trail, breaking a water pipe. Rocks also damaged fences and concrete floors in viewing areas. Small, frequent, and short-lived phreatic eruptions continued to be recorded through 18 April. A video posted by a news outlet showed an explosion ejecting incandescent material.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 5 April – 11 April 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 6-9 April ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NE, E, S, and W.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 1-6 April lava continued to advance down the NW flank of Bezymianny’s lava dome. A thermal anomaly was identified in satellite images daily. The Aviation Colour Code remained at Orange.

Bogoslof | Fox Islands (USA) : On 5 April AVO reported that the Aviation Colour Code for Bogoslof was lowered to Yellow and the Volcano Alert Level was lowered to Advisory based on the absence of detected activity at the volcano for the past three weeks; the last large explosion occurred on 8 March. No significant volcanic activity was detected in seismic, infrasound, or satellite data during 6-11 April.

Chirinkotan | Kuril Islands (Russia) : Based on Tokyo VAAC data, SVERT reported that on 7 April an ash plume from Chirinkotan rose to an altitude of 5 km (16,400 ft) a.s.l. and drifted NE. The Aviation Colour Code remained at Yellow (on a four-Colour scale).

Cleveland | Chuginadak Island (USA) : AVO reported that no significant volcanic activity at Cleveland was detected in seismic, infrasound, or satellite data since an explosion occurred on 24 March. The Aviation Colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory on 5 April.

Colima | Mexico : On 7 April the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week the seismic data revealed 38 high-frequency events, 23 long-period events, 2.4 hours of tremor, 18 landslides, and two low-intensity explosions. The sulfur dioxide flux was as high as 640 tons/day.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 5-11 April ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted NE, SE, and S.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 4-6 April several explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 4 km (13,100 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 6 April. The Aviation Colour Code remained at Orange (the second highest level on a four-Colour scale).

Etna | Sicily (Italy) : INGV reported that the eruptive episode that began on 15 March from a vent in the saddle between Etna’s Southeast Crater (SEC) – New Southeast Crater (NSEC) cone complex was characterized by Strombolian activity and ash emissions. Lava had traveled down into the Valle del Bove from the W rim; by the afternoon of 18 March almost continuous collapses of parts of the lava flow produced several avalanches of incandescent material which reached the base of the wall. Explosive activity had greatly declined earlier that morning. The collapsing stopped by early the next evening, 19 March, and the lava reached the base of the valley. That lava flow stopped advancing on 20 March though a few lava flows closer to the vent remained active the next few days. On 21 March a new lava flow expanded SSW, but then stopped in the last days of March at an elevation of 2,300 m. A few more lava flows had followed a similar path in early April and then also stopped at the same elevation. Around 28 March a new pit crater had formed on the S part of the pyroclastic cone which had formed around the SEC-NSEC saddle vent. Strong glow form the pit crater was observed at night.

Fuego | Guatemala : INSIVUMEH reported that during 6-11 April explosions at Fuego generated ash plumes that rose as high as 850 m above the crater rim and drifted as far as11 km W, SW, and S. Ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW). Rumbling from the explosions was sometimes heard. During 10-11 April incandescent material was ejected 100-150 m above the crater, generating minor avalanches in the area of the cone.

Kilauea | Hawaiian Islands (USA) : During 5-11 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water. A growing lava delta was an estimated 25 m out from the base of the sea cliff by 10 April. Surface lava flows were active above the pali and on the coastal plain.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 1-4 April explosions at Klyuchevskoy generated ash plumes that rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. Satellite images showed a thermal anomaly over the volcano during 1-2 and 4 April, and ash plumes that drifted 400 km in multiple directions. No explosions were recorded after 4 April; the Aviation Colour Code was lowered to Yellow on 10 April.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 4-11 April seismicity at Nevado del Ruiz continued to indicate unrest. Signals indicating fracturing rock slightly increased in both size and number as compared to the previous week. During 10-11 April a period of short-duration and very low energy drumbeat signals were recorded, indicating rising magma. Water vapor and gas continued to be emitted. Gas, steam, and ash plumes rose 1.5 km above the crater rim on 10 April and drifted NW. Thermal anomalies were identified on 4, 6, and 7 April. The Alert Level remained at III (Yellow; the second lowest level on a four-Colour scale).

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 6 and 8 April a webcam recorded ash emissions rising from Nevados de Chillán and dissipating quickly. On 6 April the emissions rose as high as 4 km (13,000 ft) a.s.l. Minor ash emissions were observed on 10 April.

Pacaya | Guatemala : INSIVUMEH reported that incandescence from Pacaya’s Mackenney cone was visible at night and at dawn during 6-11 April. Weak explosions accompanied by rumbling was sometimes noted.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 3-9 April seismicity at Sabancaya declined compared to the previous week, with an average of 27 explosions recorded per day. Ash plumes rose as high as 3.2 km above the crater rim (on 8 April) and drifted more than 40 km NW and NE. Ashfall was reported in Pinchollo (20 km N), Maca, and Chivay. The Buenos Aires VAAC reported that diffuse ash plumes drifted 100 km E on 9 April. Intermittent ash emissions during 10-11 April rose as high as 7 km (23,000 ft) a.s.l. and drifted SE. The Alert Level remained at Orange (the second highest level on a four-Colour scale).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 1-6 April 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, and ash plumes that drifted 20 km SE on 3 April. The Aviation Colour Code remained at Orange (the second highest level on a four-Colour scale).

Sinabung | Indonesia : Based on PVMBG observations and wind data, the Darwin VAAC reported that during 7 and 9-11 April ash plumes from Sinabung rose to altitudes of 3.4-8.2 km (11,000-27,000 ft) a.s.l. and drifted E, SE, and WNW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 5 April – 11 April 2017

Aira | Kyushu (Japan) : JMA reported that an explosion from the Minamidake summit crater (at Aira Caldera’s Sakurajima volcano) at 1004 on 4 April generated an ash plume that rose 1.2 km above the crater rim. During field work later that day, scientists observed ashfall in Sakurajima Koike-cho in Kagoshima (3 km NW). The Alert Level remained at 3 (on a 5-level scale).

Banda Api | Indonesia : PVMBG reported that seismicity at Banda Api had been increasing since the beginning of March, though during 1-4 April seismic patterns were similar to those recorded before an eruption in 1988. The Alert Level was raised to 2 (on a scale of 1-4); visitors and residents were warned not to approach Banda Api within a 1-km radius of the summit area.

Cerro Azul | Isla Isabela (Ecuador) : IG reported that deformation data showed continued inflation after 20 March, indicating that the volume of the magma intrusion below Cerro Azul’s SSE flank had increased. Seismicity decreased after 25 March possibly signifying a halt in the intrusion.

Dempo | Indonesia : Observers at the PVMBG Dempo observation post reported that during January and February no plumes rose from Dempo’s crater, and during 1 March-4 April diffuse white plumes rose no higher than 50 m above the crater. Seismicity increased from 21 March to 4 April. The Alert Level was raised to 2 (on a scale from 1-4) on 5 April. Visitors and residents were advised not to approach the craters within 3 km.

Ibu | Halmahera (Indonesia) : Based on ground observations, PVMBG reported that during 7-8 April ash plumes from Ibu rose to an altitude of 1.7 km (5,500 ft) a.s.l. and drifted N. During 10-11 April ash plumes rose to altitudes of 1.5-1.6 km (4,900-5,200 ft) a.s.l. and drifted S.

Kambalny | Southern Kamchatka (Russia) : Based on satellite data, KVERT reported that Kambalny was quiet on 1 April. Explosions on 2 April generated ash plumes that rose to an altitude of 7 km (23,000 ft) a.s.l., and then minor ash emissions occurred at least through 6 April. Ash plumes drifted 200 km E and SE during 2-4 April, and a thermal anomaly was identified in satellite images during 3-4 April. The Aviation Colour Code remained at Orange.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 29 March-4 April 2017

Ambrym | Vanuatu : The Wellington VAAC reported that a low-level ash emission from Ambrym was identified in satellite images on 3 April.

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 29 March an ash plume from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SW. On 31 March a NOTAM (notice to airmen) and pilot report suggested that an ash plume rose to an altitude of 2.1 km though ash was not identified in mostly clear satellite images. An ash plume observed on 2 April rose to an altitude of 2.1 km and drifted almost 40 km E.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that during 24-31 March lava continued to advance down the NW flank of Bezymianny’s lava dome. A thermal anomaly was identified daily in satellite images. The Aviation Colour Code remained at Orange.

Bogoslof | Fox Islands (USA) : AVO reported that no significant volcanic activity at Bogoslof was detected in seismic or infrasound data during 29 March-4 April, and satellite views were often obscured by clouds or showed nothing noteworthy. Weakly elevated surface temperatures were identified in satellite images during 28-29 March. The Aviation Colour Code remained at Orange and the Volcano Alert Level remained at Warning.

Chirinkotan | Kuril Islands (Russia) : Based on Tokyo VAAC satellite data, SVERT reported that on 31 March an ash plume from Chirinkotan rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted 165 km NE. The Aviation Colour Code was raised to Yellow (on a four-colour scale) on 2 April.

Cleveland | Chuginadak Island (USA) : AVO reported that no significant volcanic activity at Cleveland was detected in seismic or infrasound data during 29 March-4 April, and satellite views were often obscured by clouds. The Aviation Colour Code remained at Orange and the Volcano Alert Level remained at Warning.

Colima | Mexico : On 31 March the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week the seismic data revealed 45 high-frequency events, 33 long-period events, 2.5 hours of tremor, 11 landslides, and two low-intensity explosions. The sulphur dioxide flux was 360 tons/day, an increase compared to the week before.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 29 March-4 April ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 24-31 March several explosions per day at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose to altitudes of 1.5-3.4 km (4,900-11,200 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 26 March. The Aviation Colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that activity at Fuego increased on 1 April, with the beginning of a new effusive eruption, the third one in 2017. Explosions occurring an average of 10 per hour generated shock waves that vibrated local structures. An ash plume rose an estimated 1.3 km and drifted 10 km W, SW, and S; weather clouds hindered observations. Later that day lava fountains rose 100-300 m high and fed lava flows that traveled 400 m down the Trinidad (S) and Las Lajas (SE) drainages. The effusive phase lasted about 16 hours, ending on 2 April, with lava flows stopping as far as 3 km, and expanding into the Santa Teresa (W) drainage. Ash plumes drifted as far as 80 km W, causing ashfall in areas downwind including Atitlan Lake, Chicacao, Mazatenango, Retalhuleu, and El Palmar. On 4 April explosions generated ash plumes that rose 750 km and drifted S, and avalanches pf material descended the Ceniza drainage.

Kilauea | Hawaiian Islands (USA) : During 29 March-4 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water. National Park Service officials estimated that the lava delta was about 40 m wide and 100 m long. Surface lava flows were active above the pali, and small, short-lived breakouts occurred on the coastal plain.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 27-30 March explosions at Klyuchevskoy generated ash plumes that rose to an altitude of 7 km (23,000 ft) a.s.l. Satellite images showed a thermal anomaly over the volcano during the previous week, and ash plumes that drifted 300 km in multiple directions. The Aviation Colour Code remained

Lokon-Empung | Sulawesi (Indonesia) : PVMBG reported that on 25 March six climbers between the ages of 15 and 20 climbed to Lokon-Empung’s Tompaluan Crater, into the restricted area, where one of the climbers fell into the crater and died. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were reminded not to approach the crater within a radius of 1.5 km.

Reventador | Ecuador : During 28 March-4 April IG reported a high level of seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador. Although cloud cover often prevented visual observations, activity was noted almost daily. During 28 March-3 April steam, gas, and ash plumes rose as high as 1.3 km above the crater rim and drifted SW and NE. Incandescence from the crater was sometimes visible during the night. Incandescent blocks rolled 1 km down the flanks on 1 April, and 1.6 km down the SW flank on 3 April. A small lava flow was observed traveling 1.6 km down the SW flank on 3 April.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 27 March-2 April there were an average of 41 explosions recorded per day. The number and magnitude of hybrid events decreased while long-period events increased. Ash plumes rose as high as 4.8 km above the crater rim and drifted more than 40 km NW, N, and SW. Ashfall was reported in Pinchollo (20 km N) and Cabanaconde (22 km NW). Overall activity increased compared to the precious week. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 24-31 March 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, and ash plumes that drifted 20 km SW on 24 and 26 March. The Aviation Colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on PVMBG observations, satellite data, and wind data, the Darwin VAAC reported that on 29 March an ash plume from Sinabung rose to altitudes of 4.6 km (15,000 ft) a.s.l. and drifted ESE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 1 April an explosion at Suwanosejima generated a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted E

Turrialba | Costa Rica : OVSICORI-UNA reported that ash-and-gas plumes from Turrialba rose 500 m above the crater during 31 March-1 April. Ashfall was reported at the Juan Santamaría airport, 48 km W. Ash plumes rose 500 m at 1700 on 2 April, and 200 m at 0601 on 4 April.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 29 March-4 April 2017

Aira | Kyushu (Japan) : JMA reported very small eruptions at Minamidake summit crater (at Aira Caldera’s Sakurajima volcano) during 28-29 March. Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 4 April an ash plume rose to an altitude of 8 km (26,200 ft) a.s.l. and drifted W. The Alert Level remained at 3 (on a 5-level scale).

Ibu | Halmahera (Indonesia) : PVMBG reported that an eruption at Ibu at 0058 on 29 March generated an ash plume that rose to an altitude of 1.8 km (5,800 ft) a.s.l. and drifted N. Another event at 0757 on 3 April produced an ash plume that rose to an altitude of 1.7 km (5,500 ft) a.s.l. and drifted S. Seismicity on both days was characterized by events indicating explosions and avalanches.

Kambalny | Southern Kamchatka (Russia) : KVERT reported that the eruption that began at Kambalny at 2110 on 24 March continued through 31 March. Observers reported that explosions generated ash plumes that rose 5-6 km (16,400-19,700 ft) a.s.l. Satellite images showed ash plumes drifting 2,000 km W, SW, S, and SE during 24-30 March. The Aviation Colour Code remained at Orange.

Nevados de Chillan | Chile : The Buenos Aires VAAC reported that on 3 April a webcam recorded a strong ash puff from Nevados de Chillán rising to an altitude of 4.9 km (16,000 ft) a.s.l. and drifting E.