Roundup of Global Volcanic Activity
Stromboli (Eolian Islands, Italy): The activity at the volcano remains at similar elevated levels with strong spattering, intense strombolian explosions and lava overflows. Today, both the intra-crater lava flow and the one overflowing onto the upper Sciara del Fuoco from the NE hornito vent remain intermittently active. The following time-lapse video shows the latter seen from INGV's thermal webcam on the Sciara del Fuoco:
Shiveluch (Kamchatka): A moderate explosion occurred at the volcano yesterday evening (or this morning in local time). An ash plume rose to approx. 23,000 ft (7 km) altitude. Overall, the volcano has been in a comparably quiet phase recently.
Kilauea (Hawai'i): The new June 27 lava flows continue to be very active, at expense of the previously active Kahaualeʻa 2 flow which seems to have stopped being active. The lava flows expanded in area and extended approx.1.6 km (1 mi) northeast of Puʻu ʻŌʻō cone yesterday, HVO reports. It is believed that only the lowest-elevation fissure on the NE flank continued to erupt lava on Saturday.
Pavlof (Alaska Peninsula, USA): "Weak thermal signals from recent lava flows persist in satellite images. Small, discrete seismic events continue, however, and eruptive activity could resume at any time with little or no warning." (AVO)
Shishaldin (United States, Aleutian Islands): According to the Alaska Volcano Observatory, "low-level eruptive activity continues. Consistently elevated temperatures at the summit of Shishaldin Volcano were recorded in satellite images over the past 24 hours. No significant seismicity was noted. Web camera images showed no significant plume." (AVO)
Semisopochnoi (United States, Aleutian Islands): The earthquake swarm that began on June 9 continues. No sign of activity was noted in satellite images over the past 24 hours. (AVO)
Santa María / Santiaguito (Guatemala): Weak effusive activity (extrusion of very viscous blocky lava) on the upper east and southeast flanks of the Caliente dome continues and produces small avalanches. Strong degassing (but no explosions) were observed from the summit of the dome.
Fuego (Guatemala): No significant changes in activity have occurred at the volcano recently. It remains characterized by weak to moderate strombolian explosions every 1-2 hours on average, ejecting incandescent material to up to 150 m above the vent and producing ash plumes that rise 300-700 m.
Reventador (Ecuador): Effusive-explosive activity at the volcano continues, but has decreased following the recent surge of lava emission that ended about a week ago. The observatory mentions moderate activity with continuing intermittent small explosions and ash emissions. A thermal signal on MODIS satellite data shows hot deposits in the crater and on the upper eastern flank, indicating that fresh magma continues to arrive at the summit.
Sabancaya (Peru): Signs continue to show up that the volcano might be awakening: Peru's Geophysical Institute (IGP) who monitors the volcano has detected a slight increase in volcanic unrest recently. Both seismic and fumarolic activity at the volcano increased during the past 4 weeks (since 3 June). Peaks in occurrence of so-called hybrid earthquakes were detected during 18, 19 and 21 June with 146, 157, and 216 recorded events. These quakes are believed to be indicators of magma rising at depth beneath the volcano. Hypocenter depths of volcanic-tectonic earthquakes, indicators of rock-fracturing caused by internal fluid pressure and/or rising magma, have been showing an upwards trend: at the moment, they mostly range between 16 km (NE side), 10 km (E) and 6 km on the northern flank. Fumarolic emissions have become more pronounced as well. Bluish gas of magmatic SO2, white steam (water vapour) and sometimes light gray-colored emissions, possibly from small amounts of ash, were observed during a visit to the volcano.
No comments:
Post a Comment