Radiocarbon dating of east america lake levels
Based on these findings we have established a sedimentological model for tsunami deposits in lakes and shallow marine basins.Accurate radiocarbon dating of paleotsunamis are problematic because of erosion of the underlying strata, re- deposition of organic material within the tsunami deposit and also re-deposition of organic matter for many years after the tsunami event.Six different samples of such green-colored moss from different cores give an age of 7295±23 years BP, which calibrated to calendar years is 8030-8170 (2 σ range).We compared the field observations of run-up heights with maximum surface elevations from new numerical simulations of the Storegga slide generated tsunami.Coarse sand and fine gravel particles (2-6 mm) rest on this boundary.
Of these, the tsunami deposits in Shetland reach the highest elevation, indicating a run-up of at least 20 m.
Unexpectedly, we discovered plant material within the tsunami sand that is excellent for radiocarbon dating - these are green moss stems that we know were killed by the tsunami. Chlorophyll in dead plants degrades rapidly with exposure to light and oxygen.