TY - JOUR

T1 - Rapid thermokarst evolution during the mid-Holocene in Central Yakutia, Russia

AU - Ulrich, Mathias

AU - Wetterich, Sebastian

AU - Rudaya, Natalia

AU - Frolova, Larisa

AU - Schmidt, Johannes

AU - Siegert, Christine

AU - Fedorov, Alexander N.

AU - Zielhofer, Christoph

PY - 2017/5/1

Y1 - 2017/5/1

N2 - The reconstruction of Holocene thermokarst landform evolution is important to understand the potential impact of current global climate change on permafrost regions. A multi-proxy approach was applied to analyse the sedimentological and biogeochemical characteristics as well as pollen and lacustrine microfossils of a core profile drilled in a small pingo within a large Central Yakutian thermokarst basin (alas). Age–depth modelling with macrofossil 14C ages reveals high thermokarst deposit sedimentation rates and a complete thermokarst sequence spanning about 900 years during the mid-Holocene between ~6750 and 5870 cal. yr BP. In total, three stages of thermokarst landscape evolution have been identified. Thermokarst processes were initiated at ⩽6750 to 6500 cal. yr BP. Terrestrial conditions changed quickly to lacustrine conditions, and a thermokarst lake rapidly emerged and grew to an estimated size of 120–600 m diameter and 7.5–15 m depth during only ~150 years between ~6500 and 6350 cal. yr BP. The decline of thermokarst processes and lake decrease may have been affected by local hydrological conditions between ~6350 and 5870 cal. yr BP but ceased completely after 5870 cal. yr BP, likely due to climatic changes. Clear evidence for long-lasting and stable lacustrine conditions was not obtained. The study emphasises that short-term warming led to very active permafrost degradation and rapid but locally variable modification of alas and thermokarst evolution.

AB - The reconstruction of Holocene thermokarst landform evolution is important to understand the potential impact of current global climate change on permafrost regions. A multi-proxy approach was applied to analyse the sedimentological and biogeochemical characteristics as well as pollen and lacustrine microfossils of a core profile drilled in a small pingo within a large Central Yakutian thermokarst basin (alas). Age–depth modelling with macrofossil 14C ages reveals high thermokarst deposit sedimentation rates and a complete thermokarst sequence spanning about 900 years during the mid-Holocene between ~6750 and 5870 cal. yr BP. In total, three stages of thermokarst landscape evolution have been identified. Thermokarst processes were initiated at ⩽6750 to 6500 cal. yr BP. Terrestrial conditions changed quickly to lacustrine conditions, and a thermokarst lake rapidly emerged and grew to an estimated size of 120–600 m diameter and 7.5–15 m depth during only ~150 years between ~6500 and 6350 cal. yr BP. The decline of thermokarst processes and lake decrease may have been affected by local hydrological conditions between ~6350 and 5870 cal. yr BP but ceased completely after 5870 cal. yr BP, likely due to climatic changes. Clear evidence for long-lasting and stable lacustrine conditions was not obtained. The study emphasises that short-term warming led to very active permafrost degradation and rapid but locally variable modification of alas and thermokarst evolution.

KW - climate change

KW - Eastern Siberia

KW - Holocene thermal maximum

KW - palaeolimnology

KW - permafrost

KW - thermokarst deposits

KW - Climate change

KW - Permafrost

KW - Thermokarst deposits

KW - Palaeolimnology

KW - LATE QUATERNARY

KW - NORTHERN SEWARD PENINSULA

KW - EASTERN SIBERIA

KW - ALASKA

KW - LAKE

KW - LANDSCAPE DYNAMICS

KW - VARIABILITY

KW - PERIGLACIAL LANDSCAPE

KW - PERMAFROST DEGRADATION

KW - BASIN

UR - http://www.scopus.com/inward/record.url?scp=85042212621&partnerID=8YFLogxK

U2 - 10.1177/0959683617708454

DO - 10.1177/0959683617708454

M3 - Article

AN - SCOPUS:85042212621

VL - 27

SP - 1899

EP - 1913

JO - Holocene

JF - Holocene

SN - 0959-6836

IS - 12

ER -