Report on Aira (Japan) — June 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 6 (June 1986)
Managing Editor: Lindsay McClelland.
Aira (Japan) Airliner lands safely after flying through ash cloud
Please cite this report as:
Global Volcanism Program, 1986. Report on Aira (Japan) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 11:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198606-282080
Aira
Japan
31.5772°N, 130.6589°E; summit elev. 1117 m
All times are local (unless otherwise noted)
Twelve explosions . . . were recorded in June, increasing from eight in May. A total of 131 explosions were recorded January-June 1986.
Lapilli from an explosion on 10 June at 1100 broke windshields of three cars near the volcano; another windshield was broken on the 12th at 1024. Ash from the explosion on 12 June fell heavily at Kagoshima City (population 520,000), 10 km W of the volcano. Lapilli or blocks from the explosion on 24 June at 0912 broke windshields on eight cars and damaged roofs of about 30 houses near the volcano.
A TOA Domestic airlines DC9 with 152 passengers and a crew of six flew into the 24 June cloud at 1,200 m altitude, 23 minutes after it was ejected. Cockpit windshields and front surfaces of wings were badly scratched by ejecta. The airliner, enroute from Fukuoka, landed safely at Kagoshima. Damages to planes flying through volcanic clouds have occurred eight times near the volcano in the past (table 9).
Table 9. Damage to aircraft caused by tephra from Sakura-jima, 1970-June 1986. ANA: All Nippon Airways, TDA: Toa Domestic Airlines. Times are for explosions, rather than aircraft damage.
| Date | Time | Damage |
| 08 Apr 1975 | 1419 | ANA airliner (L1011): windshields cracked. |
| 25 Dec 1977 | 0859 | ANA airliner (L1011): windshields cracked. |
| 04 Dec 1978 | 1155 | ANA airliner (L1011): windshields cracked. |
| 18 Nov 1979 | 0742 | Two ANA airliners (L1011) at 0801 and 0805: windshields cracked. |
| 18 Dec 1979 | 2118 | ANA airliner (L1011): windshields cracked. |
| 24 Dec 1979 | 1740 | TDA airliner (YS11): windshields cracked. |
| 23 Nov 1982 | 1532 | Nauru Air passenger plane (B727): windshields cracked. |
| 24 Jun 1986 | 0912 | TDA airliner (DC9): windshields scratched. |
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 caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76.
Information Contacts: JMA.
