Global Volcanic Activity – New Activity for the week of 10 July – 16 July 2019
Great Sitkin | Andreanof Islands (USA) : On 15 July AVO reported that seismicity at Great Sitkin had decreased to background levels during the past few weeks with no evidence of eruptive activity in geophysical or satellite data. The Aviation colour Code was lowered to Green and the Volcano Alert Level was lowered to Normal.
Manam | Papua New Guinea : The Darwin VAAC reported that on 12 July an ash plume from Manam rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted N, based on satellite data and weather models.
Shishaldin | Fox Islands (USA) : AVO increased the Aviation colour Code for Shishaldin to Yellow and the Volcano Alert Level to Advisory on 12 July following several weeks of increasing seismicity and elevated temperatures in the summit crater identified in satellite images. In addition incandescence in the crater was visible during an overflight. Seismic tremor continued to be elevated at least through 16 July.
Stromboli | Aeolian Islands (Italy) : INGV reported that the paroxysmal explosive sequence at Stromboli on 3 July changed the morphology of the crater terrace. The rim of the terrace facing the Sciara del Fuoco was removed, and the N1 and N2 vents in Area N (north crater area, NCA) had enlarged and merged into one. After the paroxysmal event explosive activity rapidly decreased, though it remained more intense than normal. The vents of Area C-S (South Central crater area) produced explosions regularly during 8-14 July, and fed lava flows that traveled about halfway down the Sciara del Fuoco. Material from the lava-flow fronts rolled all the way to the coastline. A new lava flow from Area N (north crater area, NCA) began at 1900 on 14 July.
Ubinas | Peru : Instituto Geofísico del Perú (IGP) reported that seismic activity at Ubinas remained elevated during 1-15 July; volcano-tectonic events averaged 279 per day and long-period events (indicating fluid movement) averaged 116 events per day. Minor bluish emissions rose from the crater. The Alert Level remained at Yellow (on a 4-level scale).