Opal on sea floor in the western north Pacific

Abstract

Sediment core samples were collected at 37 stations in the western north Pacific in 1997 - 2004. Biogenic constituents were determined in the samples. Results of opal in the sediments and also settling particles which were collected by sediment traps at some stations were reported here. Opal concentrations does not vary, also many reports show decreasing profile with depth in the sediment. The opal concentration in the sediment is less than 10% in south of 30N and it is larger than 10% in north of 40N. Opal flux observed by sediment trap has similer tendency. Opal contents in settling particle corrected in deep ocean deeper than 4500m is two to three times higher than opal in the sediment.