Video below was captured by meteorologist Robert Speta of the WestPacWx during the early morning hours of February 3, 2015. Sunrise provided a reddish tint in the ash.
Notice lightning at 0:18 min.
Video courtesy of WestPacWx
Tokyo VAAC reports an explosion at 06:55 UTC today sent ash over 1.2 km, extending east.
See our report and images of Sakurajima eruption on January 31, 2015 here.
The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones.
The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.
Featured image courtesy of WestPacWx