Weathering above the tides: how iceberg-roll-generated waves shape Arctic rocky shores

A significant limitation of the current understanding of cold coast evolution is the paucity of field observations on the development of rocky coasts in glaciated parts of the Arctic. To address this gap, we present a pilot study that utilizes a Schmidt hammer to investigate variations in rock surface resistance across four distinct horizontal zones along the rocky bay of Zion Church, Ilulissat, near one of the prevailing routes of iceberg transport in western Greenland. The primary finding of the study is a substantial decrease in rock resistance within the area above the high-tide level. We relate this result mainly to waves generated by iceberg-roll events in conjunction with chemical and biological weathering. This case study seeks to elevate the status of iceberg-roll-generated waves from a mere curiosity to a substantial geomorphic agent that shapes the microrelief of Arctic coastlines.