Report on Niijima (Japan) — December 1995
Bulletin of the Global Volcanism Network, vol. 20, no. 11 (December 1995)
Managing Editor: Richard Wunderman.
Niijima (Japan) Seismic swarm on 4 December
Please cite this report as:
Global Volcanism Program, 1995. Report on Niijima (Japan) (Wunderman, R., ed.). Bulletin of the Global Volcanism Network, 20:11. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199512-284020
Niijima
Japan
34.397°N, 139.27°E; summit elev. 432 m
All times are local (unless otherwise noted)
On 4 December, many earthquakes occurred in and around the island, some of which were felt. The largest one was M 4.3.
Geological Summary. The elongated island of Niijima, SSW of Oshima, is 11 km long and only 2.5 km wide. Eight low rhyolitic lava domes are clustered in two groups at the northern and southern ends of the island, separated by an area of flat-topped domes and a low isthmus of pyroclastic deposits. The Mukaiyama complex on the south and the Atchiyama lava dome on the north were formed during eruptions in the 9th century CE, the last known activity. Shikineyama and Zinaito domes form small islands immediately to the SW and W, respectively, during earlier stages of volcanism. Earthquake swarms occurred during the 20th century.
Information Contacts: Volcanological Division, Seismological and Volcanological Department, Japan Meteorological Agency (JMA), 1-3-4 Ote-machi, Chiyoda-ku, Tokyo 100 Japan.