Report on Chachadake [Tiatia] (Japan - administered by Russia) — July 1978
Scientific Event Alert Network Bulletin, vol. 3, no. 7 (July 1978)
Managing Editor: David Squires.
Chachadake [Tiatia] (Japan - administered by Russia) 600-m vapor column
Please cite this report as:
Global Volcanism Program, 1978. Report on Chachadake [Tiatia] (Japan - administered by Russia). In: Squires, D (ed.), Scientific Event Alert Network Bulletin, 3:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197807-290030.
Japan - administered by Russia
44.353°N, 146.252°E; summit elev. 1822 m
All times are local (unless otherwise noted)
The crew of a JMSA patrol boat observed a white vapor column rising about 600 m above the summit of Tiatia on the morning of  July. Tiatia last erupted in 1973, after 161 years of quiet. [Increased thermal activity between 1974 and 1977 melted snow and emitted vapor plumes but produced no tephra (Markhinin, 1984).]
Further Reference. Markhinin, E.K., 1984, On the state of Kunashir Island volcanoes (March, 1974-May, 1982): Volcanology and Seismology, v. 5, no. 1, p. 45-52 (English translation); 1983, no. 1, p. 43-51 (in Russian).
Geologic Background. Chachadake, also known as Tiatia, consists of a beautifully symmetrical cone that rises above the broad rim of an erosionally furrowed, 2.1 x 2.4 km wide caldera. The edifice occupies the NE tip of Kunashir Island and morphologically resembles Mount Vesuvius. The pristine-looking conical central cone, mostly formed by basaltic to basaltic-andesite strombolian eruptions, rises 400 m above the floor of the caldera and contains a 400 x 250 m wide crater with two explosion vents separated by a linear septum. Fresh lava flows cover much of the SW caldera floor and have overflowed the rim, extending to the foot of the older somma, which formed during the late Pleistocene or early Holocene. A lava flow from a flank cone on the northern caldera rim reached the Sea of Okhotsk. A major explosive eruption in 1973 followed an initial historical eruption in 1812.
Information Contacts: Reuters.