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Yellow Alert issued due to unusual rapid inflation beneath Mt. Thorbjorn on Reykjanes peninsula, Iceland #YellowAlert #MountThorbjorn #reykjanes #iceland

The map shows recent earthquake activity in the area. Mt. Thorbjorn is situated just above the black triangle which indicates one of IMO’s seismographs.

Inflation has been detected in the last few days. An earthquake swarm has been ongoing during the same period. A state of uncertainty has been declared. The aviation color code has been raised to yellow for Reykjanes.

An inflation has been detected since January 21st and is centred just west of Mt. Thorbjorn on Reykjanes peninsula. The inflation is unusually rapid, around 3-4 mm per day and has accumulated to 2 cm to date. It has been detected both on continuous GPS stations and in InSAR images. The inflation is most likely a sign of magma accumulation at a depth of just a few km. If magma accumulation is causing the inflation, the accumulation is very small, with the first volume estimate is around 1 million cubic meters (0,001 km3). This is the conclusion of a meeting held with the Scientific council of the Civil Protection at the IMO this morning.

Accurate measurements of crustal deformation on Reykjanes peninsula span approx. three decades. During this period no comparable signal has been measured. This is unusual for this period. An earthquake swarm has been ongoing, since January 21st, alongside the deformation signal just east of the inflation centre (northeast of Grindavík). The largest earthquakes occurred on January 22nd and were of M3,7 and 3,6. They were felt widely on the Reykjanes peninsula and all the way to Borgarnes region. The earthquake swarm is currently in decline. Swarms like this are common and not unusual by itself in the area. The fact that an inflation is occurring alongside the earthquake swarm is a cause for concern and closer monitoring.

The inflation is centred within an active volcanic zone

The inflation is occurring on plate boundaries and within the volcanic system of Svartsengi which is either considered a separate system or part of the Reykjanes volcanic system. The last known eruption was during Reykjanes fires, which occurred between 1210-1240 AD. Within that period a several eruptions occurred within that system, thereof there were three eruptions in Svartsengi system. The eruptions were effusive (non-explosive) fissure eruptions erupting on 1-10 km long fissures. No explosive eruptions are known from this system. The largest eruption in the swarm, from 13th century, formed Arnarseturshraun lava (estimated 0,3 km3 and 20 km2). Historically, the duration of these eruptions spans from a few days up to several weeks. Seismic activity is very common in this area and is linked to the plate boundaries, geothermal activity and possible magma intrusions. The largest earthquakes measured in this area are about M5.5.

Courtesy of en.vedur.is

https://tinyurl.com/yxygq4q4

Red Alert Issued Due To Strong Eruption With Ash At Manam Volcano In Papua New Guinea

Aviation Red Alert
A relatively large explosive eruption occurred at the volcano yesterday, sending an ash plume to estimated 11 km (34,000 ft) altitude, the Darwin VAAC reported. The ash plume was drifting west over mainland Papua New Guinea and rapidly dissipated. 
 
The Aviation Color Code has been raised from Orange to Red
 
The eruption was likely one of the volcano’s frequent paroxysms involving tall lava fountains from the summit crater with associated lava flows and/or pyroclastic flows covering parts of the northeastern flanks. Thermal emissions from the volcano have been elevated recently, suggesting that there is abundant fresh lava arriving in the summit area. 
 
There are no reports of injuries or fatalities. 
 
Similar ash eruptions have been occurring in the past weeks, most notably on 24 Aug and 23 Sep. On the 24 Aug eruption, an explosive eruption produced a similar ash plume to approx. 15 km (50,000 feet) a.s.l. and lava flows that forced 2000 inhabitants of the small island to flee. 
 
According to a newspaper article, “islanders reported ash and other debris from the volcano was so thick that sunlight was totally blocked for a few hours.”
Courtesy of volcanodiscovery.com