Spatial pattern of modern sedimentation rate of Qinghai Lake and a preliminary estimate of the sediment flux

We investigated the spatiotemporal distribution of ¹³⁷Cs radioactivity in surface sediment of Qinghai Lake, and developed the spatial pattern of sedimentation rate. The ¹³⁷Cs inventory is higher near the estuary/bank area, but lower at the central lake. On the other hand, the average ¹³⁷Cs activity is lower near the estuary/bank area, but higher at the central lake. The mass accumulation rate (MAR) and the fluxes and contents of the terrestrial detritus (e.g. SiO₂, Fe₂O₃, and Ti) are higher near the estuary/bank area, but lower at the central lake. The chemical/biogenic deposits (e.g. the autogenic carbonates) take up higher fractions at the central lake. These suggest that the spatial pattern of recent sedimentation rate is dominated by the deposition of terrestrial detritus. The average MAR (0.0337g cm^-2a^-1) was estimated based on those of different cores of Qinghai Lake and was verified by a Ca mass-balance method. The fluxes of total lake sediments, terrestrial detritus, and direct atmospheric deposits were also estimated.