Mt. Kurikoma
Geology
Mount Kurikoma composition is mostly andesitic to dacitic which formed atop elevated Tertiary dacitic tuffs and sedimentary rocks; hence the volcano's volume is smaller than its height suggests. In the early construction phase, lava erupted 500 thousand years ago to the north and south. It was followed by the formation of Higashi-Kurikoma. The volcanic cone Magusadake was last active 100 thousand years ago. The summit features a caldera 4 km (2.5 mi) across which is breached to the north and occupied by the Tsurugi-dake cone. The volcano's base consists of Tertiary to Quaternary pyroclasts including sedimentary and welded tuffs. A major active reverse fault runs east to southeast of the summit.
Volcanic activity
Since 915 AD, at least two eruptions have occurred; one in 1944. Between 5,400 years and 915 years ago, two more phreatic eruptions occurred. Dead trees in Showa Lake within the volcanic complex suggest the production of volcanic gases. The 1944 eruption occurred at the present location of Showa Lake. It killed many fishes when water in the Iwaki River became discolored. Seismic activity around the volcano is frequest; the most significant was the MJMA 7.2 earthquake that struck on 14 June 2008. The 45 km (28 mi) long aftershock zone encompassed the volcano. The earthquake triggered many large landslides around the volcano's flanks, some which were destructive and deadly.
See also
References
- ^ "Kurikoma Sanso and Mount Kurikoma". ANA. Retrieved 8 January 2024.
- ^ "Kurikomayama". Global Volcanism Program. Smithsonian Institution.
- ^ Kazama, Motoki; Kataoka, Shunichi; Uzuoka, Ryosuke (2012). "Volcanic mountain area disaster caused by the Iwate–Miyagi Nairiku Earthquake of 2008, Japan". Soils and Foundations. 52 (1): 168–184. Bibcode:2012SoFou..52..168K. doi:10.1016/j.sandf.2012.01.003.
- ^ Nakada, S.; Ueki, S. "Kurikomayama" (PDF). Japan Meteorological Agency. Retrieved 8 January 2024.