Volcanos

Roundup of Global Volcanic Activity

Bardarbunga (Iceland): The Icelandic Met Office (IMO) published two great graphics showing the gradual evolution of the Holuhraun (or now called Nornahraun) lava flow field and compares it with the two largest lava fields erupted on Iceland in historic times, Laki in 1783 and Eldgjá in 934 AD. Even though it is the largest eruption in more than 150 years on Iceland, it still is much much smaller than those two. According to the latest measurements, the lava field from Holuhraun now covers 77,5 km². The eruption which had its 100th day on 9 Dec, continues with little changes and there is no end in sight. Active breakouts are located on the northern margin of the lava field, now called "Nornahraun". Earthquake activity under the central volcano remains elevated, but over the past weeks, earthquakes larger than magnitude 4 have become more rare. Recent geochemical studies of the lava show that it seems to rise directly from a source at 9-20 km depth, i.e. is generated by decompressing mantle material.

Aso (Kyushu): Strombolian activity and low ash emissions are near continuous at the Nakadake crater.

Azuma (Honshu): Japan's Met Office (JMA) detected increased seismic activity at the volcano and raised the alert level to 2. Access to the crater, a popular walking trail, is now closed.

Sinabung (Sumatra, Indonesia): The activity at the volcano remains similar as during the past weeks. The extrusion of viscous lava continues to feed a new tongue in the upper part of the southern slope. Its steep front suffers occasional collapses that trigger rockfalls and small to medium pyroclastic flows, sometimes reaching 2-3 km in length such as this morning.