Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 28 February - 6 March 2018

Aira | Kyushu (Japan) : 6.8 earthquake6.8 earthquakeed at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 26 February-5 March, two of which were explosive. An explosive event at 0031 on 27 February ejected tephra as far as 700 m and generated a plume that rose 1.3 km above the crater rim. 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 2 March an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted NE.

Cleveland | Chuginadak Island (USA) : AVO reported that elevated surface temperatures were identified in satellite images of Cleveland during 28 February-3 March. Local seismic and infrasound sensors recorded a small explosion at 0557 on 2 March prompting AVO to raise the Aviation colour Code to Orange and the Volcano Alert Level to Watch. A volcanic cloud rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted ENE. A satellite image acquired on 5 March showed no new lava effusion in the crater. The Aviation colour Code was lowered to Yellow and the Volcano Alert Level was lowered to Advisory.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 28 February, and 1-2 and 4 March, ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 23-25 and 27-28 February generated ash plumes that rose as high as 3.3 km (10,800 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that explosions at Fuego during 27-28 February and 3-5 March generated ash plumes that rose as high as 1.1 km and drifted 10-20 km W, SW, and S. Sometimes the explosions were accompanied by weak shock waves. Incandescent material was ejected as high as 300 m above the crater rim, and generated avalanches of material in the Seca (Santa Teresa, W), Cenizas (SSW), Las Lajas (SE), and Honda (E) ravines. Ash fell in areas downwind including in Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché (8 km SW), El Porvenir (8 km ENE), and Finca Palo Verde.

Kilauea | Hawaiian Islands (USA) : During 28 February-6 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on the pali.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 27 February-5 March activity at Mayon was characterized by lava effusion from the summit crater, lava fountains, steam and ash emissions, advancing lava flows on the flanks, and pyroclastic flows. Weak and intermittent lava fountains generated steam and ash plumes that rose as high as 800 m and drifted in multiple directions; rumbling sounds were audible at least within a 10-km radius. Active lava flows extended 3.3 km, 4.5 km, and 1.9 km in the Mi-isi (S), Bonga (SE), and Basud (E) drainages, respectively. During 27 February-5 March pyroclastic flows generated by collapses of lava at the fronts and margins of flows traveled 4-5 km down the flanks. On 6 March PHIVOLCS lowered the Alert Level to 3 (on a 0-5 scale) noting a decline in the intensity and frequency of events during the previous week. Data from precise leveling surveys and real-time electronic tilt continued to record deflation of the lower flanks that began on 20 February. The report 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.

Pacaya | Guatemala : INSIVUMEH reported that during 27-28 February and 3-5 March Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 20 m above the main cone. Lava flows on the SW flank advanced to 250 m.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya decreased compared to the previous week; there was an average of 12 explosions recorded per day during 26 February-4 March. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 2 km above the crater rim and drifted 30 km NW, W, and SW. The sulfur dioxide flux was high, at 2,440 tons per day on 3 March. The report noted that the public should not to approach the crater within a 12-km radius.

San Miguel | El Salvador : On 2 March SNET reported that gas plumes rose as high as 400 m above San Miguel’s crater rim during the previous week. Ash was in the emissions on 24, 26, and 28 February, and 1 March. RSAM values fluctuated between 70 and 179 units (normal values are 50-150 units) during 1-2 March. At 2200 on 5 March seismic amplitude began to increase, with RSAM values rising to 318 units by 0600 on 6 March. A webcam recorded minor gas emission during 5-6 March.

Santa Maria | Guatemala : INSIVUMEH reported that explosions at Santa María's Santiaguito lava-dome complex, detected by the seismic network during 27-28 February and 3-5 March, generated ash plumes that rose as high as 700 m and drifted S and SW. Avalanches of material descended the SE flank of the lava dome. Ash fell locally on the flanks and in San José.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images on 26 February and 1 March. The Aviation colour Code remained at Orange.