The role of hydrothermal processes in permafrost degradation on China’s Qilian Eboling Ridge

• Ice and peat-rich permafrost degrades slowly; • Peat and ground ice are as an insulation effect; • Ground ice melting regulate surface settlement and permafrost stability. Warming climate has led to permafrost degradation at varying rates, which can accelerate the release of permafrost carbon and ground ice melt. However, these impacts are not clear and the sensitivity of ice and peat-rich permafrost to climate change has not been quantified. We choose an observing site named EboA, located on ice and peat-rich permafrost on the northeastern Qinghai-Tibet Plateau, in combination with the CryoGrid community model to analyze the long-term permafrost dynamics during 1941–2023. Permafrost has been degrading, though gradually, with a soil temperature increase of 0.1°C/10a and active layer increases of 0.03 m/10a, reaching a maximum of 0.88 m. Approximately 19 mm of subsidence has occurred due to ground ice melting. This permafrost degradation is relatively small and slower than in other regions because organic carbon has a lower thermal conductivity and higher ice content, acting as an insulating layer. During the warm season, the heat exchange between the ground and the atmosphere is reduced, while in the cold season the high ground ice content facilitates heat transfer and exchange. Thus, a new understanding of ice-carbon coupling in regulating permafrost changes is presented.