New compilation of formation dates, origins and fates for lakes within the Last Glacial/Permafrost Maximum domain of the Northern Hemisphere
Global lake distribution datasets show that a vast majority of Earth’s lakes by number and area are located in the high latitudes of the Northern Hemisphere. Lakes abundance in these regions has been linked to histories of glaciation, permafrost, and peatlands (Smith et al., 2007). Although well-dat...
| Main Authors: | , , , , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2016
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/41260/ https://www.conftool.pro/icop2016/index.php?page=browseSessions&form_session=148 https://hdl.handle.net/10013/epic.48182 |
| Summary: | Global lake distribution datasets show that a vast majority of Earth’s lakes by number and area are located in the high latitudes of the Northern Hemisphere. Lakes abundance in these regions has been linked to histories of glaciation, permafrost, and peatlands (Smith et al., 2007). Although well-dated sedimentary lake records are regularly used for the reconstruction of paleoenvironmental conditions and landscape dynamics, so far no consistent panarctic database exists on the age and origin of northern high latitude lakes. Lake cores, peat cores and exposures detailed in primary literature sources often provide a complete picture of how and when lakes formed. Here, we compile an extensive dataset of 1154 unique lake basal and minimum ages from both past and extant lakes within the domain of glaciation and permafrost extent during the Last Glacial/Permafrost Maximum [Lindgren et al. 2015] collected primarily from detailed literature descriptions. We distinguish ten distinct classes of lake origin after Vincent & Laybourn-Parry [2008] and include information on the fates (both mechanism and timing) of non-extant lakes described in peat cores and exposures. Analysis of the dataset reveals an increase in rates of northern hemisphere lake formation beginning ~14,500 cal. yr BP that was sustained, with a short lull during the Younger Dryas, until it began to generally decrease after ~ 10,500 cal. yr BP. Peak lake formation in regions where ice sheets were present into the early and mid-Holocene occurred later. Formation frequencies for lakes of glacier-dependent origin (i.e. kettle, moraine-dammed, glacial scour) and glacier-independent origin (e.g. oxbow, thermokarst, coastal uplift) coincided, suggesting that climatic factors were driving processes such as glacial retreat and permafrost degradation responsible for lake formation simultaneously. The dataset also reveals a weak correlation (R2 = 0.26) between the timing of lake drainage or terrestrialization and the timing of lake establishment. Although highly ... |
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