Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 14 June – 20 June 2017

Bogoslof | Fox Islands (USA) : AVO reported that elevated surface temperatures and a small steam emission at Bogoslof were identified in satellite images during 13-14 June. Weakly elevated surface temperatures were detected on 16 June, and a 13-km-long steam plume was visible on 18 June. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 10-12 and 14-15 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Pavlof | United States : AVO reported that seismicity at Pavlof had declined since the small increase on 7 June, and no unusual activity was observed in seismic or infrasound data through 20 June. Minor steam emissions occasionally rose from the summit crater. Satellite images showed an approximately 55 km-long steam plume drifting W on 14 June, and a thermal anomaly during 15-16 and 20 June. The Aviation colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that on 15 June a diffuse plume of mainly water vapor rose 50 m above Rincón de la Vieja’s crater rim. A small hydrothermal explosion from the crater with the highly acidic lake was detected around noon on 18 June. In a report posted the next day OVSICORI-UNA noted that seismicity was characterized by low-frequency events, volcano-tectonic events, and tremor with intensifying amplitude; the seismic patterns were similar to those that preceded the phreatomagmatic events on 23 May and 11 June, though the recent seismicity was not as energetic.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 10-13 June explosions at Sheveluch produced ash plumes that rose as high as 8 km (26,200 ft) a.s.l. and drifted 1,500 km SE and NW. At 0425 on 15 June powerful explosions generated ash plumes that rose as high as 12 km (39,400 ft) a.s.l. The Aviation colour Code was raised to Red (the highest level on a four-colour scale), and then back down to Orange at the end of the day. Ash plumes drifted 1,000 km NE and SW during 15-16 June. Ash fell in Klyuchi (50 km SW), Maiskoe, Kozyrevsk (115 km SW), and Atlasovo (160 km SW).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 7 June – 13 June 2017

Aira | Kyushu (Japan) : JMA reported four events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 5-12 June, one of which was explosive. Material was ejected 800 m away the crater rim. Ash plumes rose as high as 3.2 km on 6 June and 1.9 km on 10 June. A very small event occurred at Minamidake summit crater on 5 June. The Alert Level remained at 3 (on a 5-level scale).

Asamayama | Honshu (Japan) : JMA stated that activity at Asama had been progressively increasing. During 2-5 June a plume rose less than 400 m above the active crater. Weak incandescence from the summit crater was recorded at night with a webcam. Sulfur dioxide flux was a little higher than 900 tons per day when measured on 2 June. The Alert Level remained at 2 (on a scale of 1-5).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 7-8 and 14 June ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 65 km SW, W, and NW.

Cleveland | Chuginadak Island (USA) : AVO reported that on 6 June small low-frequency earthquakes at Cleveland were recorded by the seismic network. Elevated surface temperatures identified in satellite images during 6-7 June were consistent with lava effusion at the summit crater. No volcanic activity was detected in seismic, infrasound, or cloudy satellite images during 8-13 June, though AVO noted that lava effusion may have been occurring. A thermal anomaly was identified in satellite images during 12-13 June. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 7-14 June 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. Ash plumes drifted as far as 140 km E on 7 June.

Ebeko | Paramushir Island (Russia) : Based on observations by residents of Severo-Kurilsk (Paramushir Island) about 7 km E of Ebeko, KVERT reported that explosive activity continued at the volcano during 2-9 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 8-9 June explosions at Fuego generated ash plumes that rose as high as 1.1 km above the crater rim and drifted 15 km W, NW, and N. Rumbling was noted, and block avalanches descended multiple ravines. Lahars traveled down several ravines on the SE, S, and SW flanks, especially down the Pantaleón (W) ravine. On 10 June at 1150 a lahar descended the Ceniza (SSW) drainage, carrying blocks 1 m in diameter. The lahar was 15-18 m wide and as deep as 3 m. During 10-11 June explosions produced ash plumes that rose 750-1,050 m and drifted 12-15 km W, NW, and N. Shock waves from some of the explosions were detected. Two hot lahars descended the flanks on 13 June. The first one traveled down the Pantaleón river and was 35 m wide and 2.5-3 m deep, and carried trees and blocks 2-3 m in diameter. The second lahar descended the Ceniza and was 25 m wide and 3 m deep, and carried blocks up to 2 m in diameter.

Ibu | Halmahera (Indonesia) : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 9-12 and 14 June ash plumes from Ibu rose 1.5-1.8 km (4,800-6,000 ft) a.s.l. and drifted N, W, and SSW.

Kilauea | Hawaiian Islands (USA) : During 7-13 June 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 (which had many small spattering sites along the margin) 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. Field observations on 31 May revealed that the lava delta had grown to an area of approximately 0.01 square kilometers. A solidified lava ramp extended from the tube exit high on the sea cliff down to the delta, whose leading edge was about 100 m from the tube exit on the sea cliff.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 2-9 June explosions at Klyuchevskoy generated ash plumes that rose to 5 km (16,400 ft) a.s.l. and drifted about 325 km NE, SE, and SW. A weak thermal anomaly was identified in satellite images on 4 and 8 June. 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 on 7 June ash plumes from Langila rose 2.1 km (7,000 ft) a.s.l. and drifted over 45 km NW. On 14 June ash plumes rose 1.8 km (6,000 ft) a.s.l. and drifted WNW.

Poas | Costa Rica :OVSICORI-UNA reported that during 7-13 June seismicity at Poás was characterized by low-amplitude tremor, discrete volcano-tectonic events, low-frequency events, and some periods of small long-period events with low amplitude. During 7-8 June the webcam recorded strong emissions of water vapor, magmatic gases, and particulates. A sulfur odor was reported in Alajuela, San Ramon, and Barva, and incandescence in the area of the crater was recorded at night. OVSICORI-UNA noted that during 8-9 June a plume of water vapor, magmatic gases, and particulates rose from two vents; the lake had evaporated and exposed the vents. A minor sulfur odor was reported on the campus of the Universidad Nacional in Heredia. Events at 1610 and 1750 on 11 June generated plumes that rose 300 and 600 m above the crater, respectively. Plumes from the vents rose 1 km during 12-13 June. A sulfur odor was noted in Quesada, Santa Ana, San José de Alajuela, and San Juanillo Naranjo.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya slightly decreased from the previous week; there was an average of 31 explosions recorded per day during 5-11 June. The number and magnitude of long-period and hybrid events were moderate and low, respectively. Levels of long-period events were moderate and hybrid events were low. Gas-and-ash plumes rose as high as 2.8 km above the crater rim and drifted more than 30 km E and SE. The MIROVA system detected four thermal anomalies, spread over the SE, N, and NW flanks. Sulfur dioxide flux was as high as 3,392 tons per day on 6 June.

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 12-14 June ash plumes from Sinabung rose 3.4-5.5 km (11,000-18,000 ft) a.s.l. and drifted W and S.

Turrialba | Costa Rica : OVSICORI-UNA reported that tremor amplitude at Turrialba fluctuated from low to medium levels during 7-13 June. Periods of small volcano-tectonic events and many small-amplitude long-period events were also recorded. Plumes of gas and water vapor rose as high as 1 km above the vent and drifted mainly NW, W, and SW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 7 June – 13 June 2017

Bogoslof | Fox Islands (USA) : colourAVO reported that a new lava dome at Bogoslof breached the surface of the ocean on or around 6 June, and was the first observation of lava at the surface since the start of the eruption that began in mid-December 2016. The dome was an estimated 110 m in diameter on 7 June, and then grew to 160 m in diameter by 9 June.

An explosive eruption began at 0318 on 10 June with a series of short infrasound signals which then, starting at about 0416, transitioned into several minutes-long continuous seismic and infrasound tremor signals. The events generated an ash-rich cloud that rose to an estimated altitude of 10.4 km (34,000 ft) a.s.l. and drifted NW. The Aviation colour Code (ACC) was raised to Red and the Volcano Alert Level (VAL) was raised to Warning. The eruption ended at 0528. Satellite data indicated that at least part of the volcanic cloud was more ash-rich than most in the current eruption period. On 11 June AVO noted no detectable activity in seismic or infrasound data after the event the day before. The ACC was lowered to Orange and the VAL was lowered to Watch. Satellite image acquired on 10 June and a photograph from an observer aboard a jet aircraft on 11 June suggested that the lava dome was no longer above the surface of the water, and was destroyed during the 10 June event.

A series of explosive events, each lasting 10-30 minutes, began at 1747 on 12 June and ended around 2035. Ash plumes rose 7.6 km (25,000 ft) a.s.l. and drifted SE. The ACC was raised to Red and the VAL was raised to Warning. At 0817 on 13 June a six-minute-long explosion was detected in seismic and infrasound data. A plume was not observed, likely because it was too small or below detection limits. The ACC was lowered to Orange and the VAL was lowered to Watch.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 3-8 June. Explosions on 8 June generated ash plumes that rose 2-3 km (6,600-9,800 km) a.s.l. and drifted 70 km E, SE, and SW. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Pavlof | United States : On 7 June AVO reported that during the past several days an increase in low-frequency earthquake activity was detected at Pavlof. This kind of activity can sometime precede eruptive episodes. In addition, several short-duration tremor bursts were observed, and a pilot reported a possible ash cloud to 1.2 km (4,000 ft) a.s.l. Infrasound data from instruments on the volcano and from a more distant network in Sand Point showed no evidence of significant explosive activity. AVO noted that since activity prior to eruptions of Pavlof had always been very subtle, they increased the Aviation colour Code to Yellow and the Alert Level to Advisory based on these observations. During 8-9 June gas emissions from the summit were observed in web camera images and by local observers in Cold Bay (60 km SW). AVO noted that vapor emissions (with or without minor amounts of volcanic ash) are common and may occur from the summit vent at any time.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that a small, minute-long, phreatic eruption in Rincón de la Vieja’s crater lake began at 0542 on 11 June. Poor visibility prevented visual confirmation of plume details, though the Washington VAAC reported that a thermal anomaly was present in satellite images. A small seismic signal that lasted less than one minute was recorded at 2106 on 12 June. The signal possibly represented an emission, though it was not confirmed.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 3, 5, and 7-8 June powerful explosions at Sheveluch generated ash plumes that rose as high as 8 km (26,200 ft) a.s.l. and drifted 1,554 km SW, S, and SE. Pyroclastic flows traveled 10 km. Ashfall was reported in Klyuchi Village (50 km SW) on 8 June. A thermal anomaly was identified daily in satellite images. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 31 May – 6 June 2017

Aira | Kyushu (Japan) : JMA reported 15 events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 22-29 May, two of which were explosive. Material was ejected as high as 800 m above the crater rim. Ash plumes rose as high as 3.4 km on 31 May and 3 km on 2 June. Very small events occurred at Minamidake summit crater during 4-5 June. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 3 and 5 May ash plumes from Bagana rose to altitudes of 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted W and SE.

Bogoslof | Fox Islands (USA) : AVO reported that a short-duration (less than 10 minute) explosion at Bogoslof began at 1842 on 31 May based on seismic and infrasound data. A volcanic cloud identified in satellite images rose 7.3 km (24,000 ft) a.s.l., drifted WNW, and dissipated over the Bering Sea. The explosion was preceded by a several hour-long swarm of very small earthquakes. Seismicity decreased in the hours prior to the explosion and remained below the detection threshold. A sulfur dioxide plume from an explosion on 28 May was visible in satellite data drifting over the Hudson Bay region of Canada on 2 June. A short-duration explosive event at 0750 on 5 June produced a small volcanic cloud observed by a pilot. Low-amplitude tremor was detected in seismic data beginning at about 1229 on 5 June but then decreased to background levels. A vessel in the area reported vigorous steaming and a white plume rising several thousand feet above sea level. A brief explosive event was detected at 0600 on 6 June. The event likely produced a low-level (less than 3 km or 10,000 ft a.s.l.) emission; a possible plume at 1.8 km (6,000 ft) a.s.l. was identified in a satellite image following the detection of the activity in seismic and infrasound data, but quickly dissipated. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that no significant volcanic activity at Cleveland was detected in seismic, infrasound, or cloudy satellite images during 31 May-5 June. The webcam recorded steam emissions during periods of clear weather. Small low-frequency events were recorded by the seismic station located on the flank of the volcano beginning at 0939 on 6 June. The events were consistent with lava-dome growth, but growth could not be visually confirmed. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Colima | Mexico : On 2 June the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 21 high-frequency events, 14 long-period events, 1.7 hours of tremor, 12 landslides, and zero explosions. During 25-26 May sulfur dioxide emissions were low at 35-51 tons per day, close to the detectable limits.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 31 May-6 June ash plumes from Dukono rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted NW, W, SW, and E.

Ebeko | Paramushir Island (Russia) : Based on observations by residents of Severo-Kurilsk (Paramushir Island) about 7 km E of Ebeko, KVERT reported that explosive activity continued at the volcano during 25 May-2 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported increased activity at Fuego on 1 June, characterized by an increase in the number of explosions (6-7 per hour) and ash plumes rising as high as 950 m above the crater and drifting W. Explosions generated shock waves that rattled structures in multiple areas including Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), El Porvenir, and Sangre de Cristo (8 km WSW). Incandescent material was ejected as high as 500 m above the crater rim, and caused avalanches of material on the flanks. On 2 June explosions produced ash plumes that rose 550-950 m and drifted 10-12 km W and SW. Shock waves were detected within a radius of 25 km. Incandescent material was ejected 300-500 m high, causing avalanches in the Ceniza (SSW), Taniluyá (SW), and Santa Teresa (W) drainages. During 3-4 June there were 2-4 explosions recorded per hour. Ash plumes rose 650-1,050 m high and drifted 8-10 km W and SW. Weak shock waves rattled nearby buildings. Avalanches from ejected incandescent material continued to descend the three drainages. On 4 June a hot lahar descended the Pantaleón (W) drainage, carrying blocks more than 2 m in diameter, branches, and tree trunks. The lahar was 30 m wide and had a strong sulfur odor. During 4-5 June incandescent material rose 150 m and a lava flow traveled 300 m down the Santa Teresa drainage. On 6 June INSIVUMEH noted that eruptive episode number five had ended, with remnant lava flows in the Santa Teresa (2 km long) and Ceniza (3 km long) drainage. Explosions generated ash plumes that rose 950 m and drifted 15 km W and NW.

Ibu | Halmahera (Indonesia) : PVMBG reported that eruptions at Ibu on 1 and 5 June generated ash plumes that rose 150-250 m above the crater and drifted N and SE, respectively.

Kilauea | Hawaiian Islands (USA) : During 31 May-6 June 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 (which had many small spattering sites along the margin) 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. Field observations on 31 May revealed that the lava delta had grown to an area of approximately 0.01 square kilometers. A solidified lava ramp extended from the tube exit high on the sea cliff down to the delta, whose leading edge was about 100 m from the tube exit on the sea cliff.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images during 27 and 30-31 May and 2 June. Explosions during 1-2 June generated ash plumes that rose to 6 km (19,700 ft) a.s.l. and drifted about 400 km SSE. Ash plumes drifted over Petropavlovsk-Kamchatsky and Elizovo. 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 on 1 June ash plumes from Langila rose 1.8 km (6,000 ft) a.s.l. and drifted N and NW.

Manam | Papua New Guinea : RVO reported that although weather clouds often obscured views of Manam during 1-7 June white emissions were periodically seen rising from Southern Crater and Main Crater. Seismicity was very low. The Alert Level remained at Stage 1.

Planchon-Peteroa | Central Chile-Argentina border : Based on Observatorio Volcanológico de los Andes del Sur (OVDAS) – SERNAGEOMIN observations, ONEMI reported on 17 May that the number and magnitude of earthqaukes at Planchón-Peteroa had gradually declined during the past months, reaching baseline levels. Minor to no surface activity was noted. OVDAS-SERNAGEOMIN lowered the Alert Level to Green (the lowest level on a three-colour scale), and ONEMI canceled the Yellow Alert for the communities of Molina (66 WNW), Curicó (68 km NW), Romeral (75 km NW), and Teno (68 km NW) that had been in place since 1 July 2016.

Poas | Costa Rica : OVSICORI-UNA reported that tremor amplitude at Poás fluctuated from low to medium levels during 30-31 May, often associated with the vigor of emissions of water vapor, magmatic gases, and material from vents. An event at 1200 on 2 June generated a plume consisting of water vapor, gases, and minor amounts of ash that rose 600 m above the crater. Another event recorded at 1353 could not be confirmed visually due to weather conditions. An event at 0858 on 6 June generated a plume that rose 1 km.

Popocatepetl | Mexico : Each day during 31 May-2 June CENAPRED reported 51-78 and steam and gas emissions from Popocatépetl; the daily count increased to 144-276 during 2-5 June. Explosions were detected during 31 May-1 June (1-2 per day) and during 2-5 June (13-22 per day) though cloudy conditions prevented visual confirmation of ash, gas, and steam plumes. Observers noted material being ejected 200 m from the crater on 3 June. Crater incandescence was visible on some nights. The Alert Level remained at Yellow, Phase Two.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that for the second week in a row explosive activity at Sabancaya slightly increased from the previous week; there was an average of 47 explosions recorded per day during 29 May-4 June. Seismicity was dominated by long-period events, and the number and magnitude of hybrid events were low. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted more than 40 km E and SE. The MIROVA system detected five thermal anomalies, spread over the SE, N, and NW flanks. Sulfur dioxide flux was as high as 1,703 tons per day on 3 June.

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 31 May-5 June ash plumes from Sinabung rose 3.4-5.5 km (11,000-18,000 ft) a.s.l. and drifted in multiple directions.

Turrialba | Costa Rica : OVSICORI-UNA reported that volcano-tectonic amplitude at Turrialba fluctuated from low to moderate levels during 30-31 May. Plumes of water vapor, magmatic gases, and material rose no higher than 300 m above the crater rim, sporadically contained ash, and drifted NW. On 3 June at 1930 an event produced an ash plume that rose 300 m and drifted SW. The report noted that during the previous week ash emissions had been sporadic and not generated by explosions.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 31 May – 6 June 2017

Bulusan | Luzon (Philippines) : PHIVOLCS reported that a minor phreatic eruption at Bulusan occurred at 1029 on 5 June and was recorded by the seismic network for 12 minutes. The eruption could not be visually observed due to dense weather clouds covering the summit. Minor ashfall, a sulfuric odor, and rumbling sound were reported in barangays Monbon and Cogon in Irosin, while sulfuric odor was noted in barangay Bolos, Irosin. The Alert Level remained at 1, indicating abnormal conditions and a 4-km-radius Permanent Danger Zone (PDZ).

Copahue | Central Chile-Argentina border : OVDAS-SERNAGEOMIN reported that webcams recorded an increase in ash emissions at Copahue on 4 June. There were no significant changes in the magnitude or number of earthquakes recorded by the seismic network. The report noted that due to inclement weather making visual observations difficult, the observatory did not know if the ash emission began in the early hours of 4 June, or the day before. The Alert Level was raised to Yellow (the second lowest on a four-colour scale); SERNAGEOMIN recommended no entry into a restricted area within 1 km of the crater.

Karymsky | Eastern Kamchatka (Russia) : Based on Tokyo VAAC data, KVERT reported that an explosive eruption at Karymsky began at 0040 on 4 June. An ash plume rose 3 km (9,800 ft) a.s.l. and drifted over 40 km NE. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale). Less than four hours later ash plumes rose 2 km (6,600 ft) a.s.l. and drifted 85 km ENE. The VAAC reported that a possible ash plumes rose 4 km 13,000 ft) a.s.l. during 5-6 June and drifted E.

Marapi | Indonesia : PVMBG reported four explosions at Marapi on 4 June, each lasting less than one minute. The explosions occurred at 1001, 1011, 1256, and 1550, and produced dense ash-and-steam plumes that rose 300 m, at least 700 m, 200 m, and 250 m above the crater, respectively. The plumes drifted E. Ejected bombs were deposited around the crater. Seismicity increased after the explosions. Minor ashfall was reported in the Pariangan District (8 km SSE), Tanah Datar Regency. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were advised not to enter an area within 3 km of the summit.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 26-27 and 31 May powerful explosions at Sheveluch generated ash plumes that rose 8 km (26,200 ft) a.s.l. and drifted 550 km ESE and about 650 km WSW. A thermal anomaly was identified in satellite images during 26 May-2 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 24 May – 30 May 2017

Aira | Kyushu (Japan) : JMA reported 22 events at Showa Crater (at Aira Caldera’s Sakurajima volcano) during 22-29 May, seven of which were explosive. The explosions ejected material as high as 800 m above the crater rim, and as far away as 500 m. Ash plumes rose as high as 3.3 km on 23 May and 3.4 km on 29 May. Crater incandescence was detected on 25 May. A very small event occurred at Minamidake summit crater on 26 May. The Alert Level remained at 3 (on a 5-level scale).

Bezymianny | Central Kamchatka (Russia) : On 26 May KVERT reported that after an explosive eruption at Bezymianny on 9 March, and the effusion of several lava flows onto the dome flanks, the volcano became quiet. Gas-and-steam emissions continued, along with a thermal anomaly identified in satellite images. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : An eruption at Bogoslof began at 1416 on 28 May prompting AVO to raise the Aviation colour Code (ACC) to Red and the Volcano Alert Level (VAL) to Warning. Pilot and satellite observations indicated than ash plumes rose at least 10.7 km (35,000 ft) a.s.l. and possibly as high as 13.7 km (45,000 ft) a.s.l. An observer on Unalaska Island reported seeing a large white-gray mushroom cloud form over Bogoslof, with ashfall to the W. The event lasted 50 minutes. On 29 May the ash cloud continued to drift NE. No detectable activity was observed in data from seismic or infrasound stations located on nearby Islands, and no new activity has been observed in satellite data. The ACC was lowered to Orange and the VAL was lowered to Watch.

Cleveland | Chuginadak Island (USA) : AVO reported that no significant volcanic activity at Cleveland was detected in seismic, infrasound, or mostly cloudy satellite images during 24-30 May. The webcam periodically recorded steam emissions. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Colima | Mexico : On 26 May the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 36 high-frequency events, 20 long-period events, 2.6 hours of tremor, 12 landslides, and three low-intensity explosions. On 23 May sulfur dioxide emissions were below detectable limits (8.6 tons/day). A short-lived, low-amplitude episode of tremor was detected on 24 May.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery and wind model data the Darwin VAAC reported that during 24-30 May ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NW, W, and SW. Plumes drifted over 230 km W on 27 May.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 23-24 May explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 2 km (6,600 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 24-30 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. A portion of the N Overlook crater wall collapsed into the lake, causing lake agitation and depositing tephra at the Hawaiian Volcano Observatory and Jaggar Museum. 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 a growing delta. Narrow cracks on the delta parallel to the coast were noted. Surface lava flows were active above and on the upper slopes of the pali.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that during 24-27 May ash plumes from Langila rose 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted 75-85 km W and NW.

Manam | Papua New Guinea : RVO reported that Strombolian activity at Manam’s Southern Crater during 13-14 and 18 May generated lava flows that descended the SW valley. Lava flows traveled to 180-220 m elevation during 13-14 May but were significantly small on 18 May. Activity was low on other days during 13-26 May; ash plumes rose from the crater during 15-18 May. Conditions were quiet at Main Crater. RVO recommended that the Alert Level be lowered to Stage 1.

Nevado del Ruiz | Colombia : Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 23-29 May seismicity at Nevado del Ruiz continued to indicate unrest. Five episodes of drumbeat seismicity (low-energy long-period events) were recorded between 1343 and 1930 on 29 May, likely signifying growing lava domes. Significant amounts of water vapor and gas continued to be emitted. Gas, steam, and ash plumes rose 880 m above the crater rim on 27 May and drifted NW and SW. A thermal anomaly was identified on 28 May. The Alert Level remained at III (Yellow; the second lowest level on a four-colour scale).

Pacaya | Guatemala : INSIVUMEH reported nighttime crater incandescence and small Strombolian explosions at Pacaya’s Mackenney cone during 27-28 May.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 22-28 May explosive activity at Sabancaya slightly increased from the previous week, with an average of 41 explosions detected per day. Seismcity was dominated by long-period events, and the number and magnitude of hybrid events were low. Gas-and-ash plumes rose as high as 2.8 km above the crater rim and drifted more than 30 km E and SE. The MIROVA system detected two thermal anomalies.

Santa Maria | Guatemala : INSIVUMEH reported that during 24-25 May avalanches of material from Santa María’s Santiaguito lava-dome complex traveled short distances down the flanks. During 27-30 May weak explosions generated ash plumes that rose 600-700 m and drifted W and SW. Ashfall was reported in Monte Claro (S).

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 24-29 May ash plumes from Sinabung rose 3.7-5.8 km (12,000-19,000 ft) a.s.l. and drifted in multiple directions.

Turrialba | Costa Rica : OVSICORI-UNA reported that tremor amplitude at Turrialba fluctuated from low to high levels during 23-30 May, often corresponding to emission characteristics. Periods of volcano-tectonic and long-period events were also recorded. During 24-26 May several passive and sporadic ash emissions rose no higher than 500 m above the vent and drifted NW and SW. Frequent and small explosions during 26-27 May generated ash plumes that rose higher than 500 m above the vent, and ejected material higher than 200 m and no farther than 100 m towards Central Crater. Small explosions during 27-29 May produced ash plumes that rose 300-500 m.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 24 May – 30 May 2017

Poas | Costa Rica : OVSICORI-UNA reported that tremor amplitude at Poás fluctuated between low and high levels during 23-30 May, often corresponding to the vigor of emissions of water vapor, magmatic gases, and material from fumarolic vents. During 25-26 May ashfall was reported in some communities around the volcano. Low magnitude volcano-tectonic earthquakes and small phreatic eruptions were recorded sporadically during 27-30 May.

Rincon de la Vieja | Costa Rica : OVSICORI-UNA reported that a small hydrothermal explosion occurred at 1020 on 23 May in Rincón de la Vieja’s crater lake, producing a small lahar that traveled down the N flank of the crater.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 23-25 May powerful explosions at Sheveluch generated ash plumes that rose 8 km (26,200 ft) a.s.l. and drifted 715 km in different directions. At 0830 on 25 May explosions generated ash plumes that rose 9-10 km (29,500-32,800 ft) a.s.l. and drifted 16 km NE. The Aviation colour Code (ACC) was raised to Red (the highest colour on a four-colour scale). Around 30 minutes later the ash plume was identified in satellite images drifting 45 km ENE. Strong steam-and-gas emissions rose from the lava dome. The ACC was lowered to Orange. Within the next hour the ash plume drifted 82 km E.

Volcanos

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

Aira | Kyushu (Japan) : JMA reported that 10 events at Showa Crater (at Aira Caldera’s Sakurajima volcano) were detected during 15-18 May. One of the events, an explosion at 2302 on 17 May, generated a large ash plume that rose 3 km above the crater rim and ejected material 500-800 m from the crater. That same day at 1526 an explosion at Minamidake summit crater produced an ash plume that rose 1.1 km above the crater. At 0058 on 19 May a plume rose 1.4 km above Showa Crater’s rim. Very small events occasionally occurred at Minamidake summit crater during 19-22 May. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 20-22 May ash plumes from Bagana rose 2.4 km (8,000 ft) a.s.l. and drifted W.

Bezymianny | Central Kamchatka (Russia) : KVERT reported gas-and-steam activity at Bezymianny during 12-19 May, and a thermal anomaly identified in satellite images daily. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Bogoslof | Fox Islands (USA) : AVO reported that the eruption at Bogoslof which began at 2232 on 16 May lasted about 73 minutes. Trace amounts of ash fell in the community of Nikolski on Umnak Island. Later that day the Aviation colour Code (ACC) was lowered to Orange and the Volcano Alert Level (VAL) was lowered to Watch; no further ash emissions were detected and seismicity was low. Satellite data showed that the event altered the N coastline of the island. The crater lake was breached with a 550-m-wide gap along the N shore, and the NE shore had been extended 300 m from new tephra deposits.

Cleveland | Chuginadak Island (USA) : AVO reported that a short-lived explosion at Cleveland was detected in both seismic and infrasound data at 1938 on 16 May; the seismic signal lasted about 11 minutes. An ash cloud observed in satellite images rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted SW for about five hours. The explosions completely destroyed the lava dome that was emplaced in the summit crater during April-May. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Colima | Mexico : On 19 May the Centro Universitario de Estudios e Investigaciones de Vulcanologia – Universidad de Colima reported that during the previous week seismic data revealed 25 high-frequency events, 15 long-period events, 2.2 hours of tremor, 12 landslides, and three low-intensity explosions. During 15-16 May sulfur dioxide emissions were below detectable limits (8.6 t/d).

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 18-23 May ash plumes from Dukono rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : KVERT reported that on 15 May explosions at Ebeko were observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E. Ash plumes rose as high as 2 km (6,600 ft) a.s.l. 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 19-20 and 23 May ash plumes from Ibu rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted NE, E, and S.

Kambalny | Southern Kamchatka (Russia) : On 19 May KVERT reported that the eruption at Kambalny likely had ended, with only gas-and-steam activity observed during the previous month. The explosive phase began on 24 March and ended on 10 April. The Aviation colour Code was lowered to Green.

Kilauea | Hawaiian Islands (USA) : During 17-23 May HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater; the lake rose as high as 15 m below the crater rim and was visible from Hawaii Volcanoes National Park’s Jaggar overlook. 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 a growing delta. Surface lava flows were active above and on the upper slopes of the pali.

Klyuchevskoy | Central Kamchatka (Russia) : Based on video and satellite data, KVERT reported that explosions at Klyuchevskoy on 17 May generated ash plumes that rose to 6 km (19,700 ft) a.s.l. and drifted about 180 km N and NE. A weak thermal anomaly was identified daily. 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 on 19 May an ash plume from Langila rose 4.6 km (15,000 ft) a.s.l. and drifted almost 170 km WSW and dissipated. During 19-20 May ash plumes drifted N and NNW at 1.8 km (6,000 ft) a.s.l. On 23 May ash plumes rose 2.1 and 3 km (7,000 and 10,000 ft) a.s.l. and drifted NW and SW, respectively.

Piton de la Fournaise : OVPF reported that a seismic crisis at Piton de la Fournaise began at 1340 on 17 May and was accompanied by rapid deformation that suggested rising magma; volcanic tremor was recorded at 2010. The seismic and deformation activity was located in the NE part of l’Enclos Fouqué caldera. During an overflight at 1100 on 18 May scientists observed no surface activity at the base of the Nez Coupé de Sainte Rose rampart (on the N side of the volcano) nor outside of l’Enclos Fouqué caldera, and suggested that fractures opened but did not emit lava. Seismicity increased at 0400 on 18 May. The number of shallow (2 km depth) volcano-tectonic earthquakes progressively decreased over the next three days: 40 shallow and 22 deep on 18 May, 18 shallow and 22 deep on 19 May, 7 shallow and 9 deep on 20 May, 8 shallow and 1 deep on 21 May. Carbon dioxide concentrations in soils measured at remote stations were high. During a field visit on 22 May scientists mapped the deformation associated with the 17 May event and measured displacements that did not exceed 35 cm. On 23 May OVPF reported that the 17-18 May activity resulted in two new zones of fumaroles that followed the trends seen in seismic and deformation data.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that during 15-21 May explosive activity at Sabancaya was similar to the previous week, with an average of 39 explosions detected per day. The number and magnitude of long-period and hybrid events was low. 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. The MIROVA system detected six thermal anomalies.

San Miguel | El Salvador : On 19 May SNET reported that during the previous 24 hours RSAM values at San Miguel continued to decrease, fluctuating between 69 and 80 units (typical background levels average 50 units). Sulfur dioxide flux was also lower, though changing winds may have affected readings.

Sinabung | Indonesia : Based on PVMBG observations, webcam and satellite images, and wind data, the Darwin VAAC reported that during 17-20 and 24 May ash plumes from Sinabung rose 4.3-8.8 km (14,000-29,000 ft) a.s.l. and drifted in multiple directions. BNPB reported a high-intensity eruption at the volcano on 20 May. An ash plume rose 4 km and drifted SE. There were 2,038 families (7,214 people) displaced to eight shelters, and an additional 2,863 people living in refugee camps. The Alert Level remained at 4 (on a scale of 1-4), with an exclusion zone of 7 km from the volcano on the SSE sector, and 6 km in the ESE sector, and 4 km in the NNE sector.

Turrialba | Costa Rica : OVSICORI-UNA reported that low-to-moderate amplitude tremor was recorded at Turrialba during 17-23 May. Small numbers of volcano-tectonic and long-period events were recorded during 18-19 May, and low-frequency and volcano-tectonic events were detected during 21-22 May. Ash emission were observed during 17-23 May, rising as high as 1 km above the vent. Ashfall was reported in El Tapojo and Juan Viñas (15 km SSE) during 17-18 May, and in Capellades (along with a strong sulfur odor) during 19-20 May.

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.