Probability of a great earthquake to recur off the pacific coast of central Japan

Abstract. Geological disaster by liquefaction-fluidization happened on southern part of the Quaternary Paleo-Kanto submarine basin at the 2011 Earthquake off the Pacific Coast of Tohoku. Liquefaction-fluidization phenomena occurred mainly in man-made strata over shaking 5+ intensity of Japan Meteorological Agency scale. Many subsided spots, 10–50 m width, 20–100 m length and less than 1 m depth, by liquefaction-fluidization distributed on reclaimed land around northern Tokyo bay. Large amount of sand and groundwater spouted out in the terrible subsided parts. But there are little subsidence and no jetted sand outside the terrible subsided part. Liquefaction-fluidization damaged part at the 1987 earthquake east off Chiba prefecture re-liquefied and fluidized in these parts at the 2011 great earthquake. The damaged area were more wide on the 2011 earthquake than the 1987 quake. Detailed classification maps of subsidence by liquefaction-fluidization on the 2011 grate earthquake were made by fieldwork in Chiba city around Tokyo bay. A mechanism of subsidence by liquefaction-fluidization in man-made strata was solved by geological survey with continuous large box cores on the ACE Liner and large relief peals of the cores at a typical subsided part.

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Radiolarian Fossils from Conglomerate Layers of the Upper Cretaceous Nakaminato Group Exposed Along the Pacific Coast of Ibaraki Prefecture, Central Japan: Staged Denudation of the Mid-Mesozoic Accretionary Complexes in the Kanto District

Paleontological Research ◽

10.2517/2017pr026 ◽

2018 ◽

Vol 22 (4) ◽

pp. 307-325 ◽

Cited By ~ 2

Author(s):

Hiroaki Inose ◽

Kaoru Furuuchi ◽

Tsuyoshi Ito ◽

Katsuo Sashida ◽

Sachiko Agematsu

Keyword(s):

Upper Cretaceous ◽

Pacific Coast ◽

Central Japan ◽

The Pacific ◽

Kanto District ◽

Ibaraki Prefecture

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Marine reservoir correction for the Pacific coast of central Japan using 14C ages of marine mollusks uplifted during historical earthquakes

Quaternary Research ◽

10.1016/j.yqres.2006.09.003 ◽

2007 ◽

Vol 67 (2) ◽

pp. 286-291 ◽

Cited By ~ 46

Author(s):

Masanobu Shishikura ◽

Tomoo Echigo ◽

Heitaro Kaneda

Keyword(s):

Radiocarbon Dating ◽

Pacific Coast ◽

Historical Earthquakes ◽

The Sea Of Japan ◽

Central Japan ◽

South Central ◽

Kanto Earthquake ◽

The Pacific ◽

Tectonically Active ◽

Mollusk Assemblages

AbstractIn this study we utilize marine shell samples from two levels of historically uplifted sessile mollusk assemblages and raised wave-cut benches to evaluate the marine reservoir correction (ΔR) for the Pacific coast of central Japan. Elevation measurements of the uplifted marine shells indicate that the lower assemblage emerged during the 1923 Taisho Kanto earthquake (M7.9), whereas uplift of the upper assemblage is most likely but less confidently ascribed to the 1703 Genroku Kanto earthquake (M8.2). Radiocarbon dating of carefully selected samples from the upper and lower assemblages yielded very similar ΔR values of 82 ± 33 and 77 ± 32 yr, respectively. We regard the former ΔR value as a representative and more reliable value given the uncertainty in correlation of the upper assemblage with the 1703 earthquake. This result is consistent with previously reported ΔR values for the Pacific coast of south-central Japan and areas around the Sea of Japan that are influenced by warm ocean currents. Radiocarbon dating of coseismically uplifted shells can aid in estimating marine reservoir ages in the tectonically active Japan Islands.

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