Sediment accumulation rate of the upper Gulf of Thailand were studied using 210Pbex sediment depth profile.
Spatial distribution of the accumulation rate revealed cores from the intertidal zone near the river delta, with a
water depth less than 10 m, exhibited sediment mixing throughout the cores. These cores were not suitable for
determination of sediment accumulation rate. The highest accumulation rate, 0.490 g/cm2/yr, was found at the
station near the middle close to the west side of the Gulf. The accumulation rates in the western half were higher
than those in the eastern half of the Gulf. Temporal variation showed cores in the western half of the gulf have
sedimentation rates that were increasing with time while as cores in the eastern half showed their sedimentation
rates that tended to be constant. The average sediment accumulation rates as well as the inventories of 210Pbex in
the sediment cores were in concordance with the corresponding values reported before.