Characteristics of landslides triggered by the 2018 Hokkaido Eastern Iburi earthquake, Northern Japan
- 136 Downloads
On 6 September 2018, a Mj 6.7 (Mw 6.6) earthquake with a focal depth of approximately 37 km and maximum seismic intensity of 7.0 on the Japan Meteorological Agency (JMA) scale (corresponding to approximately X on the Modified Mercalli Intensity (MMI) scale) struck the central and eastern Iburi regions of Hokkaido, Northern Japan, 1 day after the Typhoon Jebi passed through the region. Thousands of landslides were triggered and significant losses resulted from the earthquake sequence. A detailed landslide inventory map, including 5625 coseismic landslides, was delineated on the basis of 3307 published landslide sites. Most of the coseismic landslides are translational landslides of small to medium scale with high mobility and long run-out distance. Thirty-six people were killed by the landslides despite the afflicted area being sparsely populated. It is found that all the 5625 landslides spread in an elliptic area extending NNW/SSE, running approximately parallel to the strike of (active) faults in this region. The preferred aspect of the landslide-affected area is southerly, running nearly perpendicular to the NNW/SSE striking (active) faults. Most coseismic landslides are distributed in regions with seismic intensity of 7.0 to 8.0 (MMI Scale), with peak ground acceleration (PGA) of 0.4 to 0.7 g. Most of the coseismic landslides occurred at the elevation between 100 and 250 m, and the slope angle between 15° and 35°. Miocene sedimentary rock is the predominant bedrock type identified in the landslide area. Slope failures were triggered in stratified pyroclastic fall deposits, in the combination of strong seismic ground motion and intense antecedent precipitation. Sliding zone liquefaction phenomena were confirmed in the field investigation. The relationship between the old landslides (slope failures occurred prior to the Iburi earthquake) and the coseismic landslides is also discussed in this study.
KeywordsCoseismic landslides Spatial distribution Controlling factors Sliding zone liquefaction Old landslides
The authors express their sincere gratitude to Tetsuya INUI for providing useful information during field investigation. The authors gratefully acknowledge Zili DAI (Shimane University, Matsue, Japan) and Prakash DHUNGANA (Shimane University, Matsue, Japan) for their kind assistance in the field work. We are grateful for the support provided by the local government. Shuai ZHANG and Ran LI also acknowledged China Scholarship Council (CSC).
This work was financed by Fundamental Research Grant (2017–2019) of Shimane University on “Development of prediction and mitigation technologies on natural disasters in subduction zone using San-in region as a research field”.
- Arita K, Ikawa T, Ito T, Yamamoto A, Saito M, Nishida Y, Satoh H, Kimura G, Watanabe T, Ikawa T, Kuroda T (1998) Crustal structure and tectonics of the Hidaka Collision Zone, Hokkaido (Japan), revealed by vibroseis seismic reflection and gravity surveys. Tectonophysics 290(3–4):197–210CrossRefGoogle Scholar
- Fukuoka H, Sassa K, Scarascia-Mugnozza G (1997) Distribution of landslides triggered by the 1995 Hyogo-ken Nanbu earthquake and long runout mechanism of the Takarazuka golf course landslide. J Phy Earth 45(2):83–90Google Scholar
- Gnyawali KR, Maka S, Adhikari BR, Chamlagain D, Duwal S, Dhungana AR (2016) Spatial implications of earthquake induced landslides triggered by the April 25 Gorkha earthquake Mw 7.8: preliminary analysis and findings. International conference on earthquake engineering and post disaster reconstruction planning 24–26 April, 2016, Bhaktapur. Nepal:50–58Google Scholar
- Harp EL, Jibson RW (1996) Landslides triggered by the 1994 Northridge, California, earthquake. Bull Seismol Soc Am 86(1B):S319–S332Google Scholar
- Hirose W, Kawakami G, Kase Y, Ishimaru S, Koshimizu K, Koyasu H, Takahashi R (2018) Preliminary report of slope movements at Atsuma Town and its surrounding areas caused by the 2018 Hokkaido Eastern Iburi Earthquake. Rep Geol Sur Hokkaido 90:33–44Google Scholar
- Keefer DK (1998) The Loma Prieta, California, earthquake of October 17, 1989: landslides. U.S. Geological Survey Professional Paper 1551-C 185 ppGoogle Scholar
- Khazai B, Sitar N (2003) Evaluation of factors controlling earthquake-induced landslides caused by Chi-Chi earthquake and comparison with the Northridge and Loma Prieta events. Eng Geol 71(1–2):79–95Google Scholar
- Kimura G (1983) Collision tectonics in Hokkaido and Sakhalin. Accretion tectonics in the Circum-Pacific regions:123–134Google Scholar
- Okamura Y, Tsujino T, Arai K, Sasaki T, Satake K, Joshima M (2008) Fore arc structure and plate boundary earthquake sources along the southwestern Kuril subduction zone. J Geophys Res Solid Earth 113(B6)Google Scholar
- Ozaki M, Taku K (2014) 1:200,000 land geological map in the Ishikari depression and its surrounding area with explanatory note. Seamless Geoinformation of coastal zone “southern coastal zone of the Ishikari depression”, seamless geological map of costal zone S-4, Geological Survey of Japan ALSTGoogle Scholar
- Wang FW (1999) An experimental study on grain crushing and excess pore pressure generation during shearing of sandy soils: a key factor for rapid landslide motion. PhD thesis of Kyoto University. Kyoto University Research Information Repository:119Google Scholar
- Zhang Y, Yao X, Xiong T, Ma Y, Hu D, Yang N, Guo C (2010) Rapid identification and emergency investigation of surface ruptures and geohazards induced by the Ms 7.1 Yushu Earthquake. ACTA Geol Sin-Engl 84(6):1315–1327Google Scholar
- Zhang Y, Dong S, Hou C, Guo C, Yao X, Li B, Du J, Zhang J (2013) Geohazards induced by the Lushan Ms7. 0 earthquake in Sichuan Province, Southwest China: typical examples, types and distributional characteristics. ACTA Geol Sin-Engl 87(3):646–657Google Scholar