Study on the specific dynamic and thermal conditions leading an ice-hole to maintain its ice during Spring or Summer

Résumé

The aim of this study is to give a coherent explanation to the natural phenomenon named “ice-hole”. Ice presence inside some ground cavities of small depth, during short meteorological unfavourable periods - Spring or Summer – in some European geographical zones of mean altitude (600 - ~ 900m), unsubmitted to very cold temperatures, is reported since a long time. But, up today, it is not well explained because it was not a real interesting study subject.

This “ice-hole” phenomenon is based on the phase changing of which water is the typical model by its vapour, liquid and solid forms.

A first approach will be done on the basis of experiments yet effected on volumes containing ice and submitted to a continuous heating on their upper surface. Then, on an identical volume, with the same content (ice), 24h periodical sinusoidal regular temperature conditions will be applied on the upper part of this volume. The temperature amplitudes will be function of the mean seasonal values issuing of local meteorological data.

In a second step, to have a better approach of the whole conditions leading to the emergence of this phenomenon, the natural physical and structural data are taken into account and digitalised. 

The results obtained from this numerical approach show that a lot of conditions needs to be considered and can lead to the maintain of a part of ice in this type of hole.