| Summary: | Human-induced climate change will alter hydrological regimes in the Arctic. Changes in flood frequency have occurred in the past, but their study has been limited by dating problems - themselves the result of hydroclimatic events. Faced with multiple 14C AMS age-reversals in a high Arctic Svalbard lake sediment record, we applied portable optically stimulated luminescence (pOSL) profiling (verified by full laboratory measurements) and hydrological proxies. Date reversals were associated with multiple flooding and drying events over the last 700 years. We applied the same methodology to a nearby lake with no age-reversals. The resulting pOSL record was dominated by noise with no hydro-climatic signal. The results reveal that Arctic lakes can be highly sensitive to sub-centennial climatic events, or largely insensitive, and that this can be identified with luminescence profiling. These findings provide a new tool to obtain high-resolution data on system stability and resilience from lake sediments.
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