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
An island volcano on the north coast of Papua New Guinea erupted early on Saturday, forcing 2,000 villagers to flee from lava flows, the National Disaster Centre said.
Manam Island, just 10 km (6 miles) wide, is one of the Pacific nation’s most active volcanoes and is home to roughly 9,000 people.
Three villages were directly in the path of the lava flow and residents had to be evacuated to safer ground, Martin Mose, director of the PNG National Disaster Centre, told Reuters by phone.
The Rabaul Volcano Observatory (RVO) reported the eruption began at 6 a.m. local time (2000 GMT Friday), sending an ash column 15 km (50,000 feet) above sea level.
The ash falls were so heavy that trees broke under the weight, the RVO said in an information bulletin.
“The most affected areas are Baliau and Kuluguma and due to the very poor visibility caused by the ash fall, people are using torch light to move around,” it said.
The RVO’s Steve Saunders said it was an unusually large eruption.
“There are no casualties as far as we know but we are telling people to keep away from valleys for risk of mud flows … there’s a heavy thick blanket of ash on the flank and if there is heavy rainfall, we are making people aware of the threat,” he said by phone.
Saunders said the initial phase of the eruption was over but a new vent had opened, indicating more activity may be likely.
The Darwin Volcanic Ash Advisory Centre (DVAAC) issued a threat warning to aviation to reroute around the cloud, which was above the cruising level of commercial airlines.
The cloud was expected to dissipate over the next 12 hours, DVAAC meteorologist Amanda Alford told Reuters.
Previous eruptions on Manam have killed residents who breathed in the ash or were buried by landslides, according to volcanic information website volcanodiscovery.com.
Courtesy of uk.reuters.com
Agung volcano has erupted prompting the Aviation Colour Code Alert Level To YELLOW, due to volcanic eruption.