Fifty-three reviewed papers presented by contributors from 18 countries at the 11th International Conference and Field Trip on Landslides (ICFL 2005, Norway) deal with landslides in soil and rock as well as snow and slush avalanches
, providing analyses, experimental investigations, stability evalution techniques, and case studies.
Because of this careful documentation, his research is regarded as a most important contribution to our understanding of rockfalls, rockslides, snow avalanches, and slush avalanches
. He also investigated earth slides, mudflows, gullying, talus creep, solifluction, and chemical weathering, to gain a complete picture of how slope denudation occurs under periglacial conditions.