Medial moraine cosmogenic 10Be data and glacier surface velocities from four Swiss valley glaciers around Pigne d’Arolla

At valley glaciers, rockwall erosion supplies debris to glacier surfaces. Once deposited on the ice, rockwall debris is passively entrained and becomes part of the glacial system, e.g., forming medial moraines as downglacier transport continues. Where debris occurs supraglacial, it modifies ice ablation and, thus, changes in rockwall erosion and debris supply rates modify glacial debris cover and mass balance and may affect glacier retreat in response to climate change. Yet, estimates on rockwall erosion rates close to glacier surfaces are few and quantifying spatiotemporal supply patterns is not trivial.

This data publication is supplementary to the study on rockwall erosion rates at five Swiss valley glaciers around Pigne d’Arolla, by Wetterauer & Scherler (2023). We temporally and spatially assess rockwall erosion by measuring in situ-produced cosmogenic 10Be concentrations ('[10Be]measured') in medial moraine debris, which we systematically sampled along downglacier-profiles, and by comparing records from various medial moraines, which are supplied by rockwalls differing in exposure and morphology. However, as '[10Be]measured' within supraglacial debris is the sum of '[10Be]rockwall', accumulated during rockwall erosion, and '[10Be]transport', accumulated during post-depositional downglacier transport, medial moraine '[10Be]measured' should be corrected for '[10Be]transport'. If glacier velocities through time are known, '[10Be]transport' can be estimated by downglacier debris trajectory modelling. Providing our 10Be dataset and ~40-year records of glacier surface velocities from four of the five valley glaciers (Glacier du Brenay, Glacier de Cheilon, Glacier de Pièce, Glacier de Tsijiore Nouve) is the main objective of this data publication. The dataset of the fifth glacier (Glacier d’Otemma) has already been published as case study by Wetterauer et al. (2022a,b).