Strong eruption at Sakurajima volcano, ash to 4.3 km (14 000 feet) a.s.l.

A powerful explosive eruption occurred at the Showa crater of Sakurajima volcano in Kagoshima Prefecture, southwestern Japan at 02:01 UTC on April 28, 2017 (11:01 JST). Several smaller eruptions followed.

The Japan Meteorological Agency said it is the first such eruption this year and the first of such strength since July 2016.

According to the Tokyo VAAC, the volcanic ash cloud produced by the eruption at 02:01 UTC reached an altitude of 4.3 km (14 000 feet) above sea level and drifted southeast. JMA warned similar explosive eruptions might occur in the future.

JMA maintains Level 3 (orange alert), signifying the volcano is active and should not be approached. 

The last time such eruption occurred at Sakurajima was at 15:02 UTC on July 25, 2016 (00:02 JST on July 26). That eruption sent ash up to 6 km (20 000 feet) above sea level. It was the first time that the volcano spewed out smoke that high since August 18, 2013, according to the Kagoshima Meteorological Office. Before August 2013, Sakurajima erupted that high in 2006.

Sakurajima eruption on April 28, 2017. Credit: NASA Terra/MODIS

Geological summary

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. (GVP)

Featured image: Sakurajima eruption on April 28, 2017. Credit: Kyodo News Agency