How large peak ground acceleration by large earthquakes could generate turbidity currents along the slope of northern Japan Trench

Abstract Deep-sea turbidite has been used to determine the history of occurrence large earthquakes. Surface-sediment remobilization is a mechanism generation earthquake-induced turbidity currents. However, detailed surface-sediment caused by earthquake ground shaking unclear. To understand how high peak acceleration (PGA) can remobilize surface sediments, we determined age core recovered from mid-slope terrace (MST) inner slope Japan Trench in northern Sanriku turbidites generated historical earthquakes and calculate PGAs these using an empirical attenuation relation commonly Japan. Small offsets radiocarbon ages excess 210 Pb activities between hemipelagic muds suggest that resulted remobilization. 137 Cs chronologies indicate three uppermost are correlated with earthquakes, namely 1968 common era (CE) Tokachi-oki, 1933 CE Showa–Sanriku, 1896 Meiji–Sanriku Calculation for along indicates PGA > 0.6 g necessary deposition MST basin. This threshold larger than reported central may vary spatially. Moreover, deposits more frequent Trench, suggesting types M8-class might have contributed PGAs.