AVO Semisopochnoi ORANGE/WATCH – Seismicity continues; no unusual activity in satellite data

Aug 11, 2019 17:51 – Seismicity remains slightly above background with occasional discrete low-frequency earthquakes and low-level tremor. No activity observed in satellite data. It remains possible for unrest to escalate rapidly with little to no warning.

Semisopochnoi is monitored with an on-island seismic network and remotely by satellite and lightning sensors. An infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a slight delay (approximately 13 minutes) if atmospheric conditions permit.

AVO Cleveland YELLOW/ADVISORY – No eruptive activity; volcano obscured by clouds in satellite data

Aug 11, 2019 17:51 – Nothing observed in cloudy satellite images over the past day. No activity was detected in regional seismic or infrasound data.

Episodes of lava effusion and explosions can occur without advance warning. Explosions from Cleveland are normally short duration and only present a hazard to aviation in the immediate vicinity of the volcano. Larger explosions that present a more widespread hazard to aviation are possible, but are less likely and occur less frequently.

Local seismic and infrasound data, unavailable since January 26, 2019, have been restored to full …

Ol Doinyo Lengai: Crater fills up

For a long time it was relatively quiet around the world’s coldest volcano: Ol Doinyo Lengai is located in the Tanzanian part of the East African Rift Valley and produces a type of lava that is half as hot as ordinary lava with temperatures around 500 degrees Celsius. In 2008, a series of paroxysms filled the old crater and grew a new cone. Since then, the world’s coldest lava has been bubbling deep down in the new pit crater. Recent images show that the deep hole is constantly filling up. The crater floor is still inaccessible without technical aids, but slowly it rises to such an extent that one can see properly again from the crater rim. The tip of a hornito almost towers above the edge of the pit and lies approximately at the level of the more gently inclined crater rim. The video shows a crack in the hornito spraying sodium carbonate. Satellite photos confirm a weak thermal anomaly in the crater. It will be several years before the crater floor can be walked on again, unless the flow rate increases significantly.