Volcanos

Roundup of Global Volcanic Activity:

Sakurajima volcano (Kyushu, Japan) activity update

Strong vulcanian explosion from Sakurajima in the afternoon of 27 Sep (08:24 UTC, 17:24 local time); ash plume reached 13,000 ft. Activity fluctuates on a scale of few days, but remains at relatively high levels overall. Explosions from the Showa crater often follow each other at intervals of few hours, and ash plumes regularly surpass 10,000 ft altitude (something that had been more rare during the past years). Most explosions are of vulcanian type (strong fragmentation of solid material blocking the vent, generation of tall ash plumes, often with shock waves and explosion sounds) and more rarely strombolian, with mainly incandescent lava ejected in fountains of several hundred meters and only little ash. Following most explosions, the volcano usually continues to near-constantly emit ash plumes of various size for several hours. These plumes, when observed during the past days, were up to about 500 m tall, with sometimes weak strombolian activity visible reaching above the crater rim.

Jebel Zubair (Red Sea, Jemen):

New submarine volcanic eruption A submarine eruption started yesterday (28 Sep) NW of the island Jebel Zubair and SW of the site of the 2011-12 eruption. The activity manifested itself in form of a strong SO2 anomaly and steam plume spotted on satellite imagery. No signs of activity are visible on images taken on 27 Sep, which confirms that the eruption started yesterday. The presence of the significant steam plume suggests that the eruption vent is a shallow depth (less than 100 m), and possibly in the stage of producing so-called surtseyan activity (violent steam-driven explosions breach the surface with jets of water and steam, and become more and more rich in lava fragments as the vent becomes shallower).