Reconstructing air temperature and permafrost attributes associated with past periglacial structures: a case study for sorted nets from the Krkonoše Mts., Czech Republic
Abstrakt
Many regions of the world host a number relict periglacial landforms that have been inherited from colder periods of the Quaternary. So far, these assemblages have been used to reconstruct former environmental conditions particularly in two basic manners.
One is to search for a representative analogue in present-day periglacial environments. Second is based on present climatic context of active landforms.
Unfortunately, numerous problems arise with both approaches and therefore, the reconstructions are frequently considered as unreliable. Consequently, most periglacial phenomena have been widely accepted only as indicators of seasonally freezing or permafrost conditions and ground-ice presence, but this may also be dubious and rather tentative in some cases.
In this contribution, we aim to infer the palaeo-temperature and palaeo-permafrost conditions associated with relict large-scale sorted nets in the Krkonoše Mts., Czech Republic. To achieve this, we employ a multi-disciplinary approach consisting of the Monte Carlo simulation based on a simple equilibrium thermal model, the Stefan equation, in an inverse form, driven by data obtained from remote sensing, geophysical soundings, and modern analogues from elsewhere.
The results are subjected to a comprehensive uncertainty and sensitivity analysis. We introduce a robust, yet straightforward and easy-to-follow procedure to utilize these periglacial phenomena and other structures indicative of the base of palaeo-active layer to reconstruct former climate.