Smithsonian / USGS Weekly Volcanic Activity Report
Ibu (Indonesia) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

PVMBG reported that during 10-15 July white-to-gray plumes rose 200-800 m above Ibu?s crater rim. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Krakatau (Indonesia) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

PVMBG reported that an event at Anak Krakatau was recorded at 1722 on 15 July that generated an ash plume that rose 700 m and drifted N. An ash plume from a 44-second-long event recorded at 1651 on 16 July rose 500 m and drifted N; thumping and vibrations were noted at the PGA observation post. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 1 km of the crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Nevados de Chillan (Chile) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported continuing activity during 11-17 July associated with growth of the Gil-Cruz lava dome in Nevados de Chillán?s Nicanor Crater. Seismicity consisted of long-period events and tremor associated with explosions. The webcam recorded pulsating white gas emissions, nighttime incandescence, and intermittent ejection of ballistics from explosions. A local M3.7 earthquake recorded at 2055 on 13 July was associated with an explosion, and located 430 m below Nicanor Crater. Another earthquake associated with an explosion was recorded at 1530 on 14 July. The event was a local M3.9 and occurred at a depth of 1.4 km. Weather conditions inhibited visual observations of the crater, though a thermal camera measured increased thermal output with a max temperaturs of 300 degrees Celsius. A third earthquake, a M3.8 located at a depth of 1.8 km, was recorded at 0324 on 15 July. Incandescent material was ejected 340 m high. These three explosions partially destroyed the lava dome, ejecting material onto the N and NE flank. The Alert Level remained at Orange, the second highest level on a four-color scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the communities of Pinto, Coihueco, and San Fabián.

Sources: Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI) ,Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Oraefajokull (Iceland) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

After a series of meetings between the Icelandic Meteorological Office, the University of Iceland, and Iceland Geosurvey, the Iceland Department of Civil Protection and Emergency Management stated on 13 July that Öræfajökull has shown clear signs of unrest for at least the past year and a half. The report noted ongoing inflation and increased seismicity, despite a decrease in geothermal activity since December 2017. The volume change since the beginning of the unrest was about 10 million cubic meters, likely from an injection of new magma.

Source: National Commissioner of the Icelandic Police (NCIP) Department of Civil Protection and Emergency Management

Piton de la Fournaise (France) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

OVPF reported that inflation at Piton de la Fournaise began at the beginning of July. An abrupt seismic increase was detected at 2340 on 12 July, coupled with rapid deformation. Tremor beneath the N flank appeared at about 0330 on 13 July and gradually increased, and webcams recorded the emergence of lava at 0430. The eruption originated from four fissures which had a total length of 500 m, and were located upstream of Chapelle de Rosemont. Tremor intensity peaked at 0600. By 0800 all four fissures were ejecting lava as high as 20 m, and ?a?a flows had traveled over 200 m. The most upstream fissure was inactive by 1230. After a period of decreasing tremor and pulsating gas emissions the eruption ended at 2200. Strong seismicity continued to be recorded on 14 July, but then decreased over the next two days. The lava flows covered about 400 m of the trail leading to the summit.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

Sierra Negra (Ecuador) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

Based on satellite data and wind model data, the Washington VAAC reported that on 11 July gas-and-ash plumes from Sierra Negra rose 3.7 km (12,000 ft) a.s.l. and drifted almost 85 km W. Gas plumes on 13 July drifted N, NW, and SW. On 16 July gas plumes with minor amounts of ash rose 2.4 km (8,000 ft) a.s.l. and drifted SW. Incandescence was visible in webcam images.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Villarrica (Chile) - Report for 11 July-17 July 2018 - NEW
Wed, 18 Jul 2018 03:19:38 -0400

POVI reported that webcam images captured a powerful vapor plume rising from Villarrica at 1047 on 16 July. Tephra was deposited on the inner crater walls.

Source: Proyecto Observación Villarrica Internet (POVI)

Agung (Indonesia) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

PVMBG reported that an event at 1409 on 13 July generated an ash plume that rose 1.5 km above Agung?s crater rim and drifted W. An event was detected at 0452 on 15 July, though no ash was visible. An ash plume from an event at 0905 rose 1.5 km and drifted W and SE. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was unchanged at a 4-km radius.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Aira (Japan) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

JMA reported that there were nine events at Minamidake crater (at Aira Caldera?s Sakurajima volcano) during 9-17 July generating plumes that rose as high as 2.3 km above the crater rim. At 1538 on 16 July an explosion produced an ash plume that rose 4.6 km, and ejected material as far as 1.7 km E. Crater incandescence was visible at night during 16-17 July. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

Ambae (Vanuatu) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

Based on satellite data, webcam and pilot observations, and wind model data, the Wellington VAAC reported that during 16-17 July ash plumes from the vent at Ambae?s Lake Voui rose to altitudes of 2.3-9.1 km (8,000-30,000 ft) a.s.l. and drifted NE.

Source: Wellington Volcanic Ash Advisory Center (VAAC)

Cleveland (United States) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

AVO reported that unrest at Cleveland continued during 11-17 July, though nothing significant was detected in seismic or infrasound data. Weakly elevated surface temperatures were identified in satellite images on 11 July; meteorological cloud cover prevented views of the crater on the other days. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Dukono (Indonesia) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 11-12 and 14-17 July ash plumes from Dukono rose to altitudes of 1.8 km (6,000 ft) a.s.l. and drifted NW, NNE, NE, and E.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Ebeko (Russia) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 8-12 July that sent ash plumes as high as 4 km (13,100 ft) a.s.l. Satellite data showed ash plumes drifting 37 km W during 10-11 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Etna (Italy) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

INGV reported that during 9-15 July gas emissions continued to rise from Etna?s summit craters. Visibility of the fairly continuous, low-energy, Strombolian activity deep within the Northeast Crater (NEC) and Bocca Nuova was sometimes hindered by gas emissions. Ejected incandescent material fell back into the crater. Strong and prolonged roars (up to several tens of seconds) from NEC were sometimes accompanied by gray-brown and reddish ash emissions. Collapses of the crater?s inner walls widened the crater. Gas emissions from New Southeast Crater (NSEC) were weak and sometimes pulsating.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Karymsky (Russia) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

KVERT reported that during 8 and 10-12 July a thermal anomaly over Karymsky was identified in satellite images, as well as diffuse gas-and-steam plumes with some ash on 10 July. An explosion at 0550 on 17 July generated an ash plume that rose as high as 5 km (16,400 ft) a.s.l. and drifted 11 km WSW. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kilauea (United States) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

HVO reported that the eruption at Kilauea?s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 11-17 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline at multiple ocean entries. Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred almost daily, producing gas-and-ash-poor plumes. Sulfur dioxide emissions from the summit were very low. Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater. A few channel overflows occurred. The channelized ?a?a flow reached the ocean on 12 July, producing a large plume of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles), and covering the Kua O Ka La Charter School and Ahalanui Beach Park. Lava entered the ocean at several points along a broad 6-km-wide flow front, though the main entry area was at Ahalanui (750 m NE of Isaac Hale Park) by 17 July. On 13 July a new island, 6-9 m in diameter, formed a few meters offshore, possibly fed by a submarine tumulus. On 16 July explosions were noted at the main ocean entry, some were strong. Hawaii County Civil Defense Agency noted that an explosion early in the morning ejected tephra that injured 23 people on a nearby tour boat. That same day volcanologists using a RADAR gun measured an average flow velocity of 29 km/hr of lava exiting Fissure 8.

Sources: Hawaii County Civil Defense Agency ,US Geological Survey Hawaiian Volcano Observatory (HVO)

Mayon (Philippines) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

PHIVOLCS reported that at 1509 on 13 July a minor rockfall descended the Mi-isi drainage on Mayon?s S flank, generating a brownish ash cloud. The event was preceded by heavy rainfall on the upper flanks. Sulfur dioxide emissions were 2,398 tonnes/day. Precise leveling data obtained during 2-14 April indicated inflation relative to data collected in late March; electronic tilt data showed pronounced inflation on the mid-flank beginning on 25 June possibly due to a deep aseismic magma intrusion. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

Sabancaya (Peru) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 23 per day during 9-17 July. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 2.5 km above the crater rim and drifted 30 km S, SE, and E. The MIROVA system detected two thermal anomalies. The report noted that the public should not approach the crater within a 12-km radius.

Sources: Instituto Geofísico del Perú (IGP),Instituto Geológico Minero y Metalúrgico (INGEMMET)

Sheveluch (Russia) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 6-13 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Stromboli (Italy) - Report for 11 July-17 July 2018
Wed, 18 Jul 2018 03:19:38 -0400

INGV reported that activity at Stromboli during 9-15 July was characterized by ongoing Strombolian activity and degassing from multiple vents. Explosions mainly from two vents in Area N (north crater area) and three vents in Area C-S (South Central crater area) occurred at a rate of 14-19 per hour, except four per hour were recorded on 15 July. Low-intensity explosions from the N1 vent (NCA) ejected lapilli and bombs as high as 80 m. Explosions at the N2 vent (NCA) ejected tephra 120 m high. Vent C (Area C-S) produced gas emissions and sporadic spattering. Low-intensity explosions at S2 (Area C-S) ejected tephra less than 80 m high.

Source: Sezione di Catania - Osservatorio Etneo (INGV)


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