Development of an Experimental Method in Education to Aid Understanding of Rock Weathering Brought about by Freezing and Thawing

Abstract

We have developed an educational experiment to help children understand rock weathering brought about by freezing and thawing. The experiment consists of two procedures: freezing and thawing of rock pieces and strength tests of the rock pieces. We used welded tuff, called Shikotsu welded tuff or Sapporo soft stone, for the test pieces. The strength tests showed that the test pieces became weaker after 10 repetitions of freezing and thawing. The responses to a questionnaire survey of participants in the scientific events indicated that the experiment was effective in aiding an understanding of rock weathering by freezing and thawing. In some cases, the experiment did not produce any weakening of the rock pieces. In those cases, participants did not understand properly the function of freezing and thawing. This was due to the heterogeneous porphyritic characteristic of the pieces. Thus, it is necessary to improve the test pieces for a practical application of the experiment.