Size distribution, La/Yb and Th/Sc of settling particles: New approach to clarify vertical and horizontal transport mechanisms of lithogenic material in the ocean

Abstract

To understand the origins and transport processes of lithogenic particles in the western North Pacific, time-series sediment traps were deployed at Sta. KNOT(44N, 155E) during 2002-2004, and size-distribution, REEs, Th and Sc of sinking particles were measured. In the time of much input of KOSA, lithogenic particle size distribution had two peaks: in the vicinities of 3-4 um and 10 um. We divided these particles into large lithogenic particles (LLP) and small lithogenic particles (SLP) by the inflection point of size distribution. The SLP flux was increased with depth. This finding suggests that SLP is horizontally transported to the deep ocean. Chemical components of particles indicate that origin of LLP is mainly KOSA in spring and is Kurile-Kamchatka Islands in the other seasons.