Enhanced boulder weathering under late‐lying snowpatches

A Schmidt test hammer was employed to assess the aggregate surface hardness of samples of boulders dug out from under late‐lying snowpatches at sites in Switzerland, Scotland and Norway. The results were compared with an equivalent set of readings made on boulders at nearby snow‐free control sites. The results in every case reveal that the aggregate surface hardness of boulders buried by late‐lying snow is significantly less (at the 0·001 level) than that of boulders at the corresponding control sites. This result indicates that late‐lying snow significantly enhances rock weathering, probably because boulder and rock surfaces are exposed to prolonged wetting by percolating meltwater under late‐lying snowbeds.