Report on Aira (Japan) — January 1980
Scientific Event Alert Network Bulletin, vol. 5, no. 1 (January 1980)
Managing Editor: David Squires.
Aira (Japan) Explosions continue; activity since 1955 summarized
Please cite this report as:
Global Volcanism Program, 1980. Report on Aira (Japan) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 5:1. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198001-282080
Aira
Japan
31.5772°N, 130.6589°E; summit elev. 1117 m
All times are local (unless otherwise noted)
Thirty-six explosions were recorded in December by the JMA's Kagoshima Observatory (table 3), bringing the total number in 1979 to 149. Tephra cracked airplane windshields on 18 and 24 December; both planes landed safely. In January, 10 explosions had been recorded by the 27th, none of which caused any damage.
Table 3. Explosions recorded at the Kagoshima Observatory, 19 August 1979-27 January 1980. Data courtesy of JMA.
| Date | Time | Cloud Height (km) | Activity |
| 19 Aug 1979 | -- | 1.0 | -- |
| 03 Sep 1979 | -- | -- | -- |
| 07 Sep 1979 | -- | 1.2 | -- |
| 08 Sep 1979 | -- | 2.8 | -- |
| 09 Sep 1979 | -- | 0.8 | -- |
| 10 Sep 1979 | -- | -- | -- |
| 04 Oct 1979 | 0555 | 1.2 | -- |
| 08 Oct 1979 | 1025 | 1.2 | -- |
| 09 Oct 1979 | 0907 | -- | -- |
| 10 Oct 1979 | 0900 | 2.0 | -- |
| 11 Oct 1979 | 0240 | -- | -- |
| 11 Oct 1979 | 1408 | 2.0 | -- |
| 12 Oct 1979 | 0012 | -- | -- |
| 12 Oct 1979 | 2116 | -- | -- |
| 13 Oct 1979 | 0310 | -- | -- |
| 14 Oct 1979 | 0623 | 1.6 | -- |
| 14 Oct 1979 | 1321 | -- | -- |
| 14 Oct 1979 | 1957 | -- | -- |
| 14 Oct 1979 | 2247 | -- | -- |
| 15 Oct 1979 | 1403 | 1.2 | -- |
| 16 Oct 1979 | 0550 | 1.3 | -- |
| 16 Oct 1979 | 0751 | 1.5 | -- |
| 16 Oct 1979 | 1658 | -- | -- |
| 16 Oct 1979 | 1846 | -- | -- |
| 17 Oct 1979 | 2245 | -- | -- |
| 18 Oct 1979 | 0509 | -- | -- |
| 18 Oct 1979 | 1559 | -- | -- |
| 23 Oct 1979 | 1346 | 2.5 | -- |
| 26 Oct 1979 | 1503 | 2.7 | -- |
| 27 Oct 1979 | 0204 | -- | -- |
| 30 Oct 1979 | 1655 | 2.0 | -- |
| 02 Nov 1979 | 0246 | -- | -- |
| 03 Nov 1979 | 1038 | -- | -- |
| 04 Nov 1979 | 0804 | -- | -- |
| 08 Nov 1979 | 0807 | 1.5 | -- |
| 09 Nov 1979 | 1054 | -- | -- |
| 10 Nov 1979 | 0148 | -- | -- |
| 10 Nov 1979 | 1400 | -- | -- |
| 10 Nov 1979 | 1815 | -- | -- |
| 14 Nov 1979 | 0410 | -- | -- |
| 14 Nov 1979 | 1513 | 2.3 | -- |
| 15 Nov 1979 | 1623 | -- | -- |
| 16 Nov 1979 | 0156 | -- | -- |
| 18 Nov 1979 | 0742 | -- | Two airplane windshields cracked. |
| 19 Nov 1979 | 1733 | 1.8 | -- |
| 20 Nov 1979 | 1514 | 2.3 | -- |
| 20 Nov 1979 | 1522 | 2.7 | -- |
| 20 Nov 1979 | 1536 | 2.0 | -- |
| 21 Nov 1979 | 1458 | 1.6 | -- |
| 21 Nov 1979 | 1646 | 1.7 | -- |
| 21 Nov 1979 | 1806 | -- | -- |
| 21 Nov 1979 | 1920 | -- | Incandescent cinders. |
| 22 Nov 1979 | 2106 | -- | -- |
| 24 Nov 1979 | 0834 | 1.0 | -- |
| 24 Nov 1979 | 1955 | -- | Incandescent cinders, lightning. |
| 27 Nov 1979 | 2237 | -- | -- |
| 28 Nov 1979 | 0209 | -- | -- |
| 28 Nov 1979 | 1305 | 2.0 | Lightning. |
| 29 Nov 1979 | 0142 | -- | -- |
| 01 Dec 1979 | 0210 | -- | -- |
| 01 Dec 1979 | 0435 | -- | -- |
| 04 Dec 1979 | 0824 | 0.8 | -- |
| 04 Dec 1979 | 1630 | 1.0 | Lightning. |
| 10 Dec 1979 | 0352 | -- | -- |
| 11 Dec 1979 | 0147 | 1.5 | -- |
| 12 Dec 1979 | 0516 | -- | -- |
| 13 Dec 1979 | 0942 | 1.5 | -- |
| 14 Dec 1979 | 1512 | 1.4 | -- |
| 14 Dec 1979 | 1547 | 2.4 | -- |
| 15 Dec 1979 | 1247 | 1.3 | -- |
| 15 Dec 1979 | 1944 | -- | -- |
| 16 Dec 1979 | 0002 | -- | -- |
| 17 Dec 1979 | 0038 | -- | -- |
| 17 Dec 1979 | 0153 | -- | Lightning, three incandescent columns, rumbling. |
| 17 Dec 1979 | 2219 | -- | Incandescent column. |
| 18 Dec 1979 | 2118 | -- | Reflected glow after explosion. |
| 19 Dec 1979 | 2307 | -- | -- |
| 21 Dec 1979 | 0135 | -- | -- |
| 22 Dec 1979 | 0119 | -- | -- |
| 23 Dec 1979 | 1138 | -- | -- |
| 23 Dec 1979 | 1540 | -- | Rumbling. |
| 23 Dec 1979 | 1812 | -- | -- |
| 23 Dec 1979 | 2007 | -- | Rumbling. |
| 24 Dec 1979 | 1710 | 1.7 | -- |
| 24 Dec 1979 | 1740 | 2.3 | Lightning. |
| 24 Dec 1979 | 2218 | -- | Two 400-m incandescent columns, lasting 20 seconds; much lightning. |
| 24 Dec 1979 | 2227 | -- | Much lightning. |
| 24 Dec 1979 | 2231 | -- | Much lightning. |
| 25 Dec 1979 | 1059 | 0.8 | Lightning. |
| 26 Dec 1979 | 0827 | 2.0 | -- |
| 26 Dec 1979 | 1033 | 2.1 | -- |
| 26 Dec 1979 | 1049 | 2.1 | Lightning. |
| 27 Dec 1979 | 0733 | 1.0 | -- |
| 27 Dec 1979 | 0915 | 1.7 | -- |
| 28 Dec 1979 | 1151 | 2.0 | -- |
| 08 Jan 1980 | 1400 | 2.0 | -- |
| 10 Jan 1980 | 0929 | 2.5 | -- |
| 10 Jan 1980 | 1049 | 2.0 | -- |
| 18 Jan 1980 | 1322 | 1.2 | -- |
| 19 Jan 1980 | 0550 | -- | -- |
| 22 Jan 1980 | 2335 | -- | -- |
| 23 Jan 1980 | 2216 | -- | -- |
| 24 Jan 1980 | 1656 | 1.0 | -- |
| 24 Jan 1980 | 1707 | 1.3 | -- |
| 27 Jan 1980 | 0828 | 1.6 | -- |
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, Tokyo.
