The Relief Induced Decay of Glaciers at the End of a Glacial

Elevating temperatures by 3.5°C through changes of the orbital parameters, rises in wide areas the equilibrium line by about 500 m.

The reaction of Nordic lowland regions to the rise of the equilibrium line could have been dramatically. A rise of the equilibrium line by 500 m must have led to vast changes in the catchment and ablation areas. The corresponding melting process resulted in large, rapid loss of glacier area (approximately 1.5 times in the newly added ablation areas; see v. Hofer 1879; Louis 1955) (Kuhle 1998 Fig.25 step from No.3 to No.2). Being freed from ice, the lowland areas reflect only 15% of the incoming radiation and reattain a 70% heat gain.

Due to the position of the equilibrium line on steep plateau edges, on the Tibet Plateau this rise only produces a small reduction in glaciated areas. By melting, the glacier tongues receded and ascended about 800 m. They still terminated at about 1800-3500 m asl, below the average level of the plateau and the inland ice (ibid. Fig.25 No.2). Induced by the lowland areas, global warming eventually reduces Tibetan ice by way of a feedback process of raising slowly the equilibrium line.

This demonstrates that Milankovic cycles are primarily interpreted to trigger short cycles of deglaciations. Overall the Tibet inland-ice serves as stabilizer for the climate system.

Was this article helpful?

0 0

Post a comment