Semeru Volcano Volcanic Ash Advisory: DISCRETE VA EMISSIONS TO FL140 EXTN NW OBS VA DTG: 11/2337Z to 14000 ft (4300 m)
Suwanose-jima Volcano Volcanic Ash Advisory: EXPLODED AT 20210511/1949Z VA CLD UNKNOWN OBS VA DTG: 11/1940Z
Piton de la Fournaise volcano (La Réunion, France): eruption continues into second month, lava advances slowly on Grandes Pentes
View of the active cones on Piton de la Fournaise volcano (image: OVPF)
The eruption that had begun more than a month ago (in the evening of 9 April) still continues with moderate lava effusion, making this eruption one of the longer-lasting ones at the volcano in recent years.
Magma erupts from the two vents on the original eruptive fissure, where small cones have formed. The latest measurements show that the larger of the two cones now has a width of 226 m and a height of around 35 m. Mild strombolian activity and spattering is occurring at the cones having open craters, with some lava ejected to the immediate surroundings, but most of the lava is diverted directly into underground tubes and flows to the active surface flows with fronts at about 5-6 km distance downslope.
The most advanced flow front continues its slow progression in the Grandes Pentes slope and is currently at an altitude of 1200 m The last precise contour of the flow, deduced from the consistency data of the InSAR acquisitions, dates back to May 7, the flow was then located at an altitude of 1200 m, about 500 m from the Piton Fréri (formed during the eruption in October 2019, located at an altitude of about 1000 m).
According to the latest bulletin of the volcano observatory (OVPF), volcanic tremor amplitudes, a measurement of vibration caused by flowing magma and roughly proportional to the lava output rate, is still at approx. 30% compared to its peak values early on. It is following a slowly declining trend, but an end of the eruption is certainly not in sight.
Latest lava flow map (image: OVPF)
Semisopochnoi volcano (Aleutian Islands): Volcanic Alert Level lowered to Yellow
Semisopochnoi volcano visible from satellite on 4 May (image: Sentinel 2)
The Alaska Volcano Observatory (AVO) reported that the alert level for the volcano was lowered to „yellow“, as no ash emissions/explosions have been recorded since 26 April.
Satellite images of the volcano confirmed no recent ash deposits or elevated surface temperatures and only steam emissions were observed within the North Cerberus crater.
Sulfur dioxide (SO2) emissions, detected on 1 and 5 May, indicate continuing seismic unrest at the volcano.
Source: Alaska Volcano Observatory volcano activity update 11 May 2021