Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 8 February-14 February 2017 – cont.

Sabancaya | Peru : Based on webcam views, satellite images, and seismic data the Buenos Aires VAAC reported that during 8-10 and 12-14 February sporadic gas-and-ash puffs rose from Sabancaya as high as an altitude of 9.1 km (30,000 ft) a.s.l.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 3-10 February lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed an ash plume that drifted 112 km NW on 4 February and a thermal anomaly over the dome during 5 and 7-9 February. The Aviation Colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, satellite and webcam images, and wind data, the Darwin VAAC reported that during 8-13 February ash plumes from Sinabung rose to altitudes of 3.4-6.7 km (11,000-22,000 ft) a.s.l. and drifted W, SW, and SE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 9 February an explosion generated an ash plume from Suwanosejima that rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted SE.

Turrialba | Costa Rica : OVSICORI-UNA reported that at 1610 on 8 February an ash plume rose 300 m above Turrialba’s active vent and drifted N. An event at 1531 on 10 February also produced an ash plume but inclement weather prevented estimates of the plume height. During 11-12 February variable amplitude tremor was detected, and at night hot blocks ejected from the vent landed in Cráter Central. Several events on 13 February (at 0255, 0305, 0415, and 1459) produced ash plumes that rose as high as 1 km and drifted N, NW, and W. Several small ejections of incandescent material fell around the active crater during the early morning. On 14 February continuous emissions of gas and steam with low ash content were visible. A strong sulphur odor was reported in San Pablo de Oreamuno (25 km SW).

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 8 February-14 February 2017

Bogoslof | Fox Islands (USA) : AVO reported that during 8-12 and 14 February cloud cover prevented satellite views of Bogoslof; no other data indicated eruptive activity. At 0724 on 13 February seismicity significantly increased, prompting AVO to raise the Aviation Colour Code (ACC) to Red and the Volcano Alert Level (VAL) to Warning. Satellite images acquired through 0930 showed no ash emissions above the 3 km (10,000 ft) a.s.l. cloud deck, and no lightning was detected. AVO concluded that, despite the intensity of seismic activity, a significant ash emission was not produced during this event; the ACC was lowered to Orange and the VAL was lowered to Watch.

Colima | Mexico : The Universidad de Colima reported that a large explosion at Colima was recorded at 1732 on 3 February, generating an ash plume that rose 6 km above the crater rim and drifted SSW. A small pyroclastic flow traveled down the E flank. The report stated that the internal crater is about 250 m in diameter and 50-60 m deep; previous lava domes had been destroyed in late September and mid-November 2016. On 9 February the sulphur dioxide gas flux was low (19 tons/day). Based on webcam and satellite images, the Washington VAAC reported that on 11 February an ash plume rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted W. On 14 February an ash plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted NE.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 8-14 February ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted S, SE, and E

Ebeko | Paramushir Island (Russia) : On 10 February KVERT reported that activity at Ebeko had declined, though gas-and-steam emissions continued. The Aviation Colour Code was lowered to Yellow (the second lowest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 8-14 February HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. All surface flows were active within 2.4 km of Pu’u ‘O’o. 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 portion of the sea cliff just W of the ocean entry collapsed on 11 February.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 8 February-14 February 2017

Cleveland | Chuginadak Island (USA) : AVO reported that weakly elevated surface temperatures in Cleveland’s summit crater were identified in satellite images during 7-9 February. Minor steaming was noted on 8 February. AVO noted that these observations were consistent with the presence of a lava dome that began extruding in the summit crater in late January. The Aviation Colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Pacaya | Guatemala : On 9 February INSIVUMEH reported that moderate explosions at Pacaya’s Mackenney cone had been detected during the previous few days. Incandescent material was ejected 30-50 m high and filled a large part of the crater; lava spilled over the crater rim and traveled 300 m down the NW flank. Incandescent material was ejected as high as 30 m during 11-12 February. Small Strombolian explosions were visible on 13 February. The lava flow continued to advance the next day.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that during 8-14 February volcanic tremor at Piton de la Fournaise was high, with levels reaching those observed at the onset of the eruption on 31 January. The eruptive vent was perched on top of a cone that was 30-35 m high and 190 m wide (at the base). The lava level inside of the cone was low, or about half of cone’s height, and incandescent material was ejected from the vent. Lava was mainly transported through a lava tube, though a few branches at end of tube were active.

Takawangha | Andreanof Islands (USA) : On 10 February AVO stated that the seismic swarm that began at Takawangha on 23 January had significantly declined the previous week and that seismicity was nearly at background levels. The Aviation Colour Code was lowered to Green and the Volcano Alert Level was lowered to Normal.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 1 February-7 February 2017 – cont.

Kilauea | Hawaiian Islands (USA) : During 1-7 February HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu’u ‘O’o.

HVO geologists noted an extensive crack running parallel to the sea cliff about 5-10 m behind the stream of lava entering the ocean at Kamokuna. The crack was 30 cm wide on 28 January and 70 cm wide four days later, on 1 February. In addition, the seaward block bounded by this crack was visibly moving up to 1 cm, and ground shaking could be felt up to several hundred meters away. On 2 February the crack was wider and steaming, and the stream of lava that had been pouring into the ocean from an opening in a lava tube about 20 m above the water was no longer visible (though lava continued to enter the ocean). At about 1255 almost the entire section of the sea cliff that was seaward of the hot crack collapsed. The collapsed block generated a wave that propagated outward from the coast. After the collapse, no lava was visible entering the ocean though a steam plume and spatter from explosions indicated that the entry remained active.

Sabancaya | Peru : Based on webcam and satellite views, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 2-6 February. Weather clouds sometimes prevented visual observations.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 27 January-3 February lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, satellite and webcam images, and wind data, the Darwin VAAC reported that during 2-7 February ash plumes from Sinabung rose to altitudes as high as 7.3 km (24,000 ft) a.s.l. and drifted NE, E, SE, and SW.

BNPB reported that each day during 2-7 February there were 8-12 ash-producing events with plumes rising as high as 2 km above the crater and drifting E. Pyroclastic flows traveled as far as 2 km S, SE, and E. BNPB noted that more areas had been designated disaster prone, therefore the number of people needed to be relocated also increased. 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 : On 1 February OVSICORI-UNA reported that since 27 January the seismic network at Turrialba recorded variable-amplitude, discontinuous tremor indicative of moving pressurized volcanic fluid. Passive emissions of ash were observed during 1-2 February, rising as high as 500 m above the crater. Ashfall was reported in Desamparados, Calle Blancos, and Tres Ríos, and a sulphur odour was noted in San Pablo Heredia. An eruption at 0900 on 4 February generated an ash plume that rose 300 m and drifted W. Almost continuous ash emissions rose at most 500 above the crater during 4-5 February and drifted WSW. Variable-amplitude tremor continued to be recorded.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 1 February-7 February 2017

Bogoslof | Fox Islands (USA) : AVO reported that no further emissions were detected at Bogoslof after an explosion at 0520 on 31 January; the Aviation Color Code (ACC) was lowered to Orange and the Volcano Alert Level (VAL) was lowered to Watch the next day. A burst of tremor lasting nine minutes was detected starting at 0457 on 3 February. A second burst, starting at 0533 and lasting 20 minutes, was also detected by infrasound instruments, indicating an explosion. No ash cloud was detected above the meteorological cloud deck in satellite data. An event that began at 1642 produced a small volcanic plume that drifted about 40 km N below an altitude of 7.6 km (25,000 ft) a.s.l. Seismic tremor significantly decreased later that evening. Weakly elevated surface temperatures were observed in two satellite images acquired on 5 February, possibly related to hot deposits from explosive activity the day before.

Colima | Mexico : The Washington VAAC reported that on 1 February an ash emission was recorded by the webcam rising from Colima. Weather clouds prevented satellite observations of the event. Based on webcam and satellite images, the Mexico City MWO, and model data, the VAAC noted that during 3-6 February ash plumes rose to altitudes of 5.2-7.6 km (17,000-25,000 ft) a.s.l. and drifted NW, W, SW, and S.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 1-2 and 5-7 February ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted at least 130 km SE and E.

Ebeko | Paramushir Island (Russia) : KVERT reported that moderate gas-and-steam emissions possibly containing small amounts of ash continued at Ebeko during 27 January-3 February. Minor ashfall was reported in Severo-Kurilsk (Paramushir Island) about 7 km E on 30 January. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Fuego | Guatemala : In a special report from 2 February, INSIVUMEH noted increased activity at Fuego characterized by explosions occurring every 5-15 minutes. Ash plumes rose as high as 750 m and drifted 15 km W, causing ashfall in areas downwind including Sangre de Cristo and San Pedro Yepocapa. During 2-7 February explosions generated ash plumes that rose 0.4-1.1 km above the crater and drifted at most 12 km NW, W, SW, and S. Incandescent material was ejected 150 m high, and avalanches traveled down the Taniluyá (SW) and Ceniza (SSW) drainages. Ashfall was reported in areas downwind including Sangre de Cristo (8 km WSW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Rochela, and Panimaché I and II (8 km SW). Shock waves from explosions rattled nearby structures.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 1 February-7 February 2017

Chirinkotan | Kuril Islands (Russia) : On 6 February SVERT noted that the Aviation Colour Code for Chirinkotan had been lowered to Green (lowest level on a four-colour scale).

Cleveland | Chuginadak Island (USA) : On 3 February AVO reported that recent satellite data indicated that a new lava dome had been extruded, and partially filled Cleveland’s summit crater. The new dome is about 70 m in diameter, similar in size to previous lava domes that have developed on the crater floor. Since explosive activity has sometimes followed lava-dome extrusion, AVO increased the Aviation Color Code to Orange and the Volcano Alert Level to Watch. Weakly elevated surface temperatures were identified in several satellite images during 6-7 February, consistent with the presence of a lava dome that began forming in late January.

Takawangha | Andreanof Islands (USA) : On 3 February AVO stated that the seismic swarm that began at Takawangha on 23 January continued but at a decreased rate and intensity. The rate of earthquakes peaked at 190 events on 24 January, and since then had steadily declined; 2-8 events per day were recorded from late January to 3 February. Most of the events were located 7-8 km ESE, at shallow depths. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Piton de la Fournaise | Reunion Island (France) : OVPF reported that seismicity and inflation at Piton de la Fournaise significantly increased on 2 January. Based on seismic data, an eruption began at 1940 on 31 January. Visual observations on 1 February confirmed that the active vent was located about 1 km SE of Château Fort and about 2.5 km ENE of Piton de Bert. Lava fountains rose 20-50 m above the 10-m-high vent, and ‘a’a lava flows branched and traveled 750 m. Two other cracks had opened at the beginning of the eruption but were no longer active. Tremor levels decreased in the early hours of the eruption; RSAM values then fluctuated at mid-range, and lava-fountain heights were variable (between 20-50 m). On 2 February two lava fountains at the vent were visible, and lava flows had traveled an additional 500 m E. The vent was 128 m long and about 35 m high at the highest part. The next day RSAM levels were more stable, at a value which was half of what it was at the beginning of the eruption. On 4 February OVPF noted that significant fluctuations of volcanic tremor were detected for more than 24 hours, with intensity levels reaching those observed at the onset of the eruption. Higher levels of seismicity continued through 7 February. Poor weather conditions prevented visual observations during 4-7 February.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 25 January-31 January 2017 – Cont.

Nevado del Ruiz | Colombia : Based on analysis of satellite images, the Washington VAAC reported that on 31 January an ash plume from Nevado del Ruiz rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted W.

Popocatepetl | Mexico : Each day during 25-31 January CENAPRED reported 2-55 steam and gas emissions from Popocatépetl and crater incandescence at night. The Alert Level remained at Yellow, Phase Two.

Sabancaya | Peru : Based on webcam and satellite views, and seismic data, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 25-31 January. Weather clouds sometimes prevented visual observations. A field team from IGP’s Observatorio Vulcanológico del Sur (OVS) visited Sabancaya on 26 January and observed ash plumes from explosions rising about 2 km above the crater rim.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 20-27 January lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, Indonesian Met Office observations, satellite images, and wind data, the Darwin VAAC reported that during 27-30 January ash plumes from Sinabung rose 3.3-4.6 km (11,000-15,000 ft) a.s.l. and drifted SW and SSE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 26 January an ash plume from Suwanosejima rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE.

Turrialba | Costa Rica : Based on webcam views, the Washington VAAC reported ongoing ash emissions at Turrialba on 27 January.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 25 January-31 January 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 25 January an ash plume from Bagana rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.

Bogoslof | Fox Islands (USA) : AVO reported that no further emissions were detected at Bogoslof after an explosion at 0453 on 24 January; the Aviation Color Code (ACC) was lowered to Orange and the Volcano Alert Level (VAL) was lowered to Watch the next day. An hour-long seismic increase began at 0134 on 25 January though no evidence of eruptive activity was evident. Based on lightning and seismic data an explosive event began at 0650 on 26 January, and another burst of seismicity was recorded at 0706. The ACC was raised to Red and the VAL was raised to Warning. An ice-rich cloud, first identified in satellite data at 0700, likely contained ash, and rose as high as 9.8 km (32,000 ft) a.s.l. and drifted SE at lower altitudes, and NE at altitudes above about 6.1 km (20,000 ft) a.s.l. The ACC was lowered to Orange and the VAL was lowered to Watch later that day. Lightning and seismic data again indicated an explosive event at 0824 on 27 January, prompting AVO to raise the Aviation Colour Code (ACC) to Red and the Volcano Alert Level (VAL) to Warning. An ice-rich cloud that likely contained ash rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted E; seismicity related to ash emissions remained elevated for 48 minutes. The ACC was lowered to Orange and the VAL was lowered to Watch later that day.

Several short bursts of seismic activity were detected at 0520 and 0608 on 30 January. An infrasound signal accompanied the first event indicating an explosion; an eruption cloud was identified in satellite data at 0530, rising to an altitude of 6.1 km (20,000 ft) a.s.l. later that day AVO noted that bursts of explosive activity continued and intensified; more than 10 short-duration explosions were detected in seismic, infrasound, and lightning data. The Aviation Colour Code (ACC) was raised to Red and the Volcano Alert Level (VAL) was raised to Warning. Ash plumes rose as high as 7.6 km (25,000 ft) a.s.l. and drifted 125 km SE. Trace amounts of ashfall and a sulphur odour were reported in Unalaska/Dutch Harbour (98 km E). By the next day the explosions had subsided or ended. Satellite images acquired on 31 January showed significant changes to the island. AVO stated that freshly erupted volcanic rock and ash had formed a barrier that separated the vent from the sea, suggesting that the change had resulted in the more ash-rich emissions occurring during 30-31 January.

Colima | Mexico : Based on webcam and satellite images, the Mexico City MWO, and model data, the Washington VAAC reported that during 25-29 January ash plumes from Colima rose to altitudes of 4.7-7 km (17,000-26,000 ft) a.s.l. and drifted NE. Ash plumes were identified in satellite images at least 370 and 650 km NE of Colima on 25 and 27 January, respectively.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, model data, and notices from PVMBG, the Darwin VAAC reported that during 25-26 and 29-31 January ash plumes from Dukono rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted NE, E, ESE, and SW.

Ebeko | Paramushir Island (Russia) : KVERT reported that moderate gas-and-steam emissions possibly containing small amounts of ash may have continued at Ebeko during 20-27 January. The Aviation Colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : Based on INSIVUMEH notices, CONRED reported that at 1345 on 25 January a Strombolian phase began at Fuego. Weak-to-moderate explosions generated ash plumes that rose 750 m above the crater rim and drifted 10 km W and SW. Lava fountains rose 200 m above the crater rim and fed lava flows that traveled 1 km SSW down the Ceniza drainage. Avalanches of material advanced more than 300 m down the Ceniza and Trinidad (S) drainages into vegetated areas. Ash fell on the SW and W flanks. The report also noted that a previous Strombolian phase had begun on 3 January.

INSIVUMEH reported that during 27-31 January explosions generated ash plumes that rose 500-900 m and drifted 5-10 km W, SW, S, and SE. Avalanches of material descended the Ceniza, Trinidad, and Santa Teresa (W) drainages.

Kilauea | Hawaiian Islands (USA) : During 25-31 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu’u ‘O’o.

HVO noted that thermal images showed a high-temperature area about 5-10 m from the edge of the sea cliff, with hot cracks running parallel to the cliff around the entry point, suggesting sea cliff instability. HVO scientists did not observe significant delta development from ground vantage points on 29 January. A stream of lava continued to pour into the ocean from an opening in a lava tube about 20 m above the water.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 25-27 January ash plumes from Langila rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. and drifted NW and N.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 25 January-31 January 2017

Chirinkotan | Kuril Islands (Russia) : Based on satellite images, SVERT reported that on 26 and 29 January ash plumes from Chirinkotan rose to an altitude of 3.5 km (11,500 ft) a.s.l. and drifted at most 105 km E and S. The Aviation Colour Code remained at Yellow (on a four-colour scale).

Erta Ale | Ethiopia : According to Volcano Discovery, visitors noted changes at Erta Ale’s lava lake during 16-20 January characterized by waves in the lava lake, intense spattering, fountaining, and rim overflows (mainly on 17 January) which traveled as far as 1 km. During the evening of 20 January explosions of very large gas bubbles ejected spatter 30 m high. Crater rim collapses affected the N crater where a new oval-shaped pit crater (150 x 30 m and 20 m depth) formed during a 24-hour period. A large collapse also occurred in the S part of the crater. The activity was accompanied by ash emissions that rose as high as 800 m. The report noted that on 21 January new fissures opened SSE from the summit caldera, producing large amounts of lava.

Satellite images acquired and processed by Planet Labs showed the new lava flows and gas-and-steam emissions from several vents (about 1.5 km SE from the overflow area at the SE caldera rim) on 23 January, and more new lava flows on 27 January. Both images showed lava flows advancing WSW, about 2.5 km S, and about 3 km NE. According to NASA’s Earth Observatory, a satellite image acquired on 26 January showed two distinct infrared hotspots representing the SE lava flows. On 27 January Simon Carn stated that the eruption produced the largest SO2 emissions from Erta Ale ever measured from space.

Etna | Sicily (Italy) : INGV reported that on the morning of 15 December 2016 minor emissions of brownish ash rose from the vent in the saddle between the newer cone and the old cone of Etna’s Southeast Crater (SEC). That evening some of the emissions were more energetic, ejecting incandescent material out of the crater which landed on the steep S flank of the SEC cone. Analysis of samples of the ejected rock revealed no new material, only older material from the conduit walls. During the following five weeks weak ash emissions from the vent were observed, without being accompanied by incandescence.

During the early morning of 20 January the saddle vent was again active, with small black ash puffs and thermal anomalies identified by the surveillance camera. People on the SEC observed ejected incandescent material along with ash and blocks. Cloudy weather prevented visual observations for a few days; the evening of 23 January was cloud free and mild Strombolian activity was observed, accompanied by frequent emissions of small, black ash puffs. The activity gradually intensified through the night, with some explosions launching incandescent material as far as the base of the SEC cone. Fluctuating incandescence was also visible at the 7 August 2016 vent of the Voragine (VOR) crater. The frequency of explosions and ash emissions increased on 24 January but then slightly decreased the next morning.

Takawangha | Andreanof Islands (USA) : On 27 January AVO stated that the seismic swarm that began at Takawangha on 23 January had significantly decreased during the previous day. The rate of earthquakes peaked at 190 events on 24 January and had steadily decreased to 22 detected on 27 January. Most of the events were located 7-8 km ESE, at shallow depths. The swarm continued at a decreased rate and intensity through 31 January. The Aviation Colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Unnamed | Tonga Islands : Based on analysis of satellite images, GeoNet reported that a submarine eruption at an Unnamed volcano (GVP volcano number 243030) about 46 km NW of Tonga’s capital Nuku’alofa began on 23 January. Activity was also identified in images from 26, 28, 29, and 31 January, characterized by discoloured water, and a volcanic plume on 31 January.

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Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 18 January-24 January 2017 – Cont.

Pacaya | Guatemala : INSIVUMEH reported that at night during 21-22 January incandescence was reflected from emissions above Pacaya’s Mackenney cone. In a 24 January report, INSIVUMEH noted that gas-and-ash emissions had continued, with deposits filling in the crater on top of the cone. Nighttime incandescence continued to be observed.

Sabancaya | Peru : Based on webcam and satellite views, the Buenos Aires VAAC reported that sporadic gas-and-ash puffs rose from Sabancaya during 17-24 January. Meteorological cloud cover sometimes prevented observations.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 13-20 January lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome. The Aviation Colour Code remained at Orange.

Sinabung | Indonesia : Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 19-20, 22, and 24 January ash plumes from Sinabung rose 3.9-4.9 km (13,000-16,000 ft) a.s.l. and drifted NW, SW, and SE.

Turrialba | Costa Rica : Based on webcam and satellite views, the Washington VAAC reported that on 22 January an ash plume from Turrialba rose to an altitude of 4 km (13,000 ft) a.s.l. and drifted E.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 18 January-24 January 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery, the Darwin VAAC reported that on 19 January an ash plume from Bagana rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE. On 24 January ash plumes visible in satellite images and observed by a pilot rose to altitudes of 3-4.3 km (10,000-14,000 ft) a.s.l and drifted almost 140 km NE.

Colima | Mexico : The Unidad Estatal de Protección Civil de Colima reported that at 0027 on 18 January a moderate-to-large explosion at Colima ejected incandescent material as far as 2 km onto the W, SW, SE, and N flanks. Based on webcam and satellite images, the Mexico City MWO, and pilot observations, the Washington VAAC reported that during 18-24 January ash plumes from Colima rose to altitudes of 4.1-6.7 km (15,000-25,000 ft) a.s.l. and drifted in multiple directions. On 19 January explosions were recorded by the webcam and noted by the Jalisco Civil protection agency; ashfall was also reported in Comala and Cuauhtémoc by the agency. A strong thermal anomaly was identified in satellite images. Remnant ash clouds were centered about 350 km SE on 20 January and about 185 km S on 22 January. A large ash plume rose to an altitude of 10.7 km (35,000 ft) a.s.l. on 23 January and drifted NE.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, model data, and notices from PVMBG, the Darwin VAAC reported that during 18-24 January ash plumes from Dukono rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted S, SW, W, and NW.

Kilauea | Hawaiian Islands (USA) : During 18-24 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. All surface flows were active within 2.4 km of Pu’u ‘O’o.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 13-20 January gas-and-steam emissions from Klyuchevskoy sometimes contained minor amounts of ash. Satellite images showed a daily thermal anomaly over the volcano. On 22 January an ash plume rose to altitudes of 5-5.5 km (16,400-18,000 ft) a.s.l. and drifted 45 km E. The Aviation Colour Code was raised to Orange (the second highest level on a four-colour scale), but was again lowered to Yellow on 24 January.

Masaya | Nicaragua : Based on satellite images, the Washington VAAC reported that on 21 January a possible emission from Masaya with minor ash content drifted almost 25 km NW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 18 January-24 January 2017

Bogoslof | Fox Islands (USA) : AVO reported that an explosive event at Bogoslof began at about 1320 on 18 January, generating an ash plume that rose at least to an altitude of 9.4 km (31,000 ft) a.s.l. and drifted NE. The dark (ash-rich) plume was identified in satellite images and observed by a pilot, and produced lightning strikes and infrasound signals detected by sensors in Sand Point and Dillingham. Analysis of a satellite image suggested the presence of very hot material (lava) at the surface immediately surrounding the vent, which was the first such observation since the beginning of the eruption. AVO raised the Aviation Color Code (ACC) to Red and the Volcano Alert Level (VAL) to Warning. A second lower-altitude cloud was visible in satellite images around 1400, likely corresponding with an increase in seismic tremor that occurred from 1340-1355. The ACC was lowered to Orange and the VAL was lowered to Watch the next day.

Another explosion was detected at 1317 on 20 January, following an approximately 30-minute-long increase in seismic activity, based on seismic data and lightning detected from the World Wide Lightning Location Network. Pilots observed an ash plume rising to an altitude of 11 km (36,000 ft) a.s.l. and drifting SE. Satellite images indicated an ice-rich plume and lava present at the vent. The ACC was raised to Red and the VAL was raised to Warning, but were again lowered one level to Orange and Watch, respectively, the next day. Several lightning strikes north of Bogoslof indicated that an explosive event began at 1409 on 22 January. An ash plume identified in satellite images rose to an altitude of 9.1 km (30,000 ft) a.s.l. The ACC was raised to Red and the VAL was raised to Warning, and again lowered one level the next day. Following a period of increasing seismicity, an explosive event began at 0453 on 24 January, as indicated in seismic data and lightning detection, prompting AVO to raise the ACC to Red and the VAL to Warning. Seven minutes later an ice-rich plume which likely contained ash rose too altitudes of 7.6-10.7 km (25,000-35,000 ft) a.s.l. and drifted E.

Ebeko | Paramushir Island (Russia) : On 19 January KVERT reported that activity at Ebeko had decreased significantly, and only steam-and-gas emissions had been observed since 12 January. The Aviation Color Code was lowered to Green (the lowest level on a four-color scale). According to observers in Severo-Kurilsk (Paramushir Island) about 7 km E, ash plumes rose to an altitude of 2 km (6,600 ft) a.s.l. and drifted 3 km SW on 19 January. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale).

Takawangha | Andreanof Islands (USA) : AVO reported that an energetic earthquake swarm on Tanaga Island began on 23 January, with earthquakes located 6-7 km ESE of Takawangha volcano, and was possibly due to brittle failure in the surrounding rock caused by magma movement. AVO raised the Aviation Color Code to Yellow and Alert Level to Advisory.

Volcanos

Roundup of Global Volcanic Activity

Etna (Sicily, Italy): A long period of bad weather conditions prevented direct observation of Etna’s summit over the past weeks. Nonetheless during brief moments of visibility a faint glow from the Voragine could be observed, together with discontinuous ash emissions from the South East Crater. Since last night weak strombolian activity from the South East Crater has started and this has intensified during the day. Additionally, on the 19th of January there have been four seismic events at shallow depths on the Pernicana fault in the NE flank of the volcano.

Volcanos

Roundup of Global Volcanic Activity

Bogoslof (United States, Aleutian Islands): Yet another powerful explosion occurred at the volcano today at 13:17 AKST local time (22:17 GMT). It produced a plume that rose to 36,000 ft (12 km) altitude and drifted to the southeast over the southwest end of Unalaska Island. The eruption, among the strongest so far, followed an 30 minute period of increasing seismic activity. During the eruption, the Alaska Volcano Observatory (AVO) reported very hot material (likely lava) at the vent seen on satellite data, a single lightning strike and infrasound signals detected by sensors in Dillingham. The Aviation Colour Code of Bogoslof volcano remains at RED and the Alert Level remains at WARNING. (AVO)

Colima (Western Mexico): Vulcanian-type (sudden, but very strong) explosions continue to occur at the volcano. Following the powerful eruption early on Thu 19 Jan, another, an even stronger explosion – one of the most energetic in recent years – occurred in the evening of the same day at 22:16. It started with a violent cannon-shot like explosion that propelled incandescent bombs to heights well over 2000 meters and covered the whole cone and its lower flanks with impacts, igniting bush fires. Pyroclastic flows from collapsing material also descended the flanks and an ash plume rose to several kilometres height. Some of the explosions are large enough to send incandescent bombs all over the summit cone and produce small pyroclastic flows and eruption lightning.

Volcanos

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

Colima | Mexico : Based on webcam and satellite images, and the Mexico City MWO, the Washington VAAC reported that during 11-17 January ash plumes from Colima rose to altitudes of 4.1-6.4 km (15,000-24,000 ft) a.s.l. and drifted in multiple directions.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, model data, and notices from PVMBG, the Darwin VAAC reported that during 11-17 January ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted almost 300 km N, NE, E, and SE.

Kilauea | Hawaiian Islands (USA) : During 11-17 January HVO reported that the lava lake continued to rise and fall, circulate, and spatter in Kilauea’s Overlook vent. Webcams recorded incandescence from long-active sources within Pu’u ‘O’o Crater and from a vent high on the NE flank of the cone. The 61G lava flow, originating from a vent on Pu’u ‘O’o Crater’s E flank, continued to enter the ocean at Kamokuna. Active surface flows near Pu’u ‘O’o advanced ESE; one branch was 2.4 km from the vent on 12 January.

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 12-13 and 15 January ash plumes from Langila rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted ESE and SE.

Nevado del Ruiz | Colombia : Based on information from Servicio Geológico Colombiano (SGC), the Washington VAAC reported that on 13 January an ash emission rose from Nevado del Ruiz to an altitude of 7 km (23,000 ft) a.s.l. and drifted N. Weather clouds prevented satellite views of the emission, and the webcam recorded gas-and-steam emissions with possible ash content.