Abstract
This paper examines the relationship between the extent of permafrost during the Last Permafrost Maximum (LPM, largely between 22 and 17 ka BP) and the altitudinal and latitudinal temperature gradients that controlled its extent. The region chosen, namely, the Qinghai-Tibet Plateau and the transition to the northern adjacent plains in the North China Plain, is of relatively limited extent in order to avoid regional effects. This area extends over 15 degrees of latitude while altitudes vary from 1000 to 1500 m above sealevel (asl) in the northern plains to more than 4000 m asl in the central-to-south part of the Qinghai-Tibet Plateau. The respective lowest southernmost permafrost occurrences at a northern and a southern position are used for reconstruction of the latitudinal and altitudinal gradients. As a first approximation, we conclude that the elevation compensation during the LPM for a 1° latitude change was between 309 m and 385 m. This is considerably higher than the value calculated for existing permafrost in the region that uses thermal data at a depth of zero amplitude change (139–198 m altitudinal compensation for 1° latitude).
Original language | English |
---|---|
Article number | 106909 |
Pages (from-to) | 1-7 |
Number of pages | 7 |
Journal | Geomorphology |
Volume | 350 |
Early online date | 6 Nov 2019 |
DOIs | |
Publication status | Published - 1 Feb 2020 |
Funding
HMF acknowledges the assistance and support of Huijun Jin, Lanzhou, CAS , for coordinating fieldwork carried out on the Qinghai-Tibet Plateau in 2014 and on the Ordos Plateau in 2015 and 2017. Fieldwork by JV was supported by the State Key Laboratory of Frozen Soils Engineering (SKLFSE, CAS), Lanzhou in 2015 and 2018. The research of HJ was supported by the National Natural Science Foundation of China (NSFC) in the project on ‘Formation, modern state of Pleistocene cryogenic deposits in Eastern Asia, and forecast of their dynamics in relation to the ongoing climatic variations’ (Grant No. 41811530093 ). The new field research at Madoi (Qinghai Province) has been carried out by XW and SY in the framework of the NSFC (Grant nr. 41522101). Frank Lehmkuhl and another anonymous reviewer are thanked for their most helpful comments.
Funders | Funder number |
---|---|
National Natural Science Foundation of China | 41522101, 41811530093 |
Chinese Academy of Sciences | |
State Key Laboratory of Frozen Soil Engineering |
Keywords
- LPM
- North China
- Permafrost extent
- Permafrost zonation
- Qinghai-Tibet Plateau
- Sand wedge
- West China