Linkages between turbidites in the southern Okinawa Trough and submarine earthquakes

Abstract

Turbidite layers in surficial (<0.4 m) sediments of the southern Okinawa Trough and its vicinity were dated by 210Pb and further constrained by 137Cs and inter-site correlation of downcore profiles of particle size and porosity. Here we show striking temporal and spatial correspondence of such episodic deposits to large (ML > 6.8) submarine earthquakes recorded in the region since the 20th century. The repeating pattern of turbidite layers reported here on decadal to centennial time scales suggests what may be the long-term rhythm of seismic activities at this tectonically active plate boundary. Copyright 2004 by the American Geophysical Union.