Abstract: We present the results of a study of the morphometric properties of a talus slope in subarctic Quebec (Nunavik) using field-based methods, including geomorphological, granulometric and plant distribution surveys, and statistical analyses. Slope processes are currently active, despite the limited altitudinal difference between the apical-to-distal parts of the slope and the imminent depletion of the debris supply. The near-rectilinear long profiles of the talus highlight the distribution of debris across the slope and demonstrate that free-fall of rock fragments is not the only process operating (redistribution is higher in the westernmost profile, which exhibits a clear concave shape). The spatial distribution of vegetation covering the screes highlights the recent age of parts of the talus, showing that present-day processes are still active, although limited. The short remaining apical rockwall highlights the shortage of debris following deglaciation, as debris are mostly supplied by freeze-thaw processes to the talus, and are then reworked by other processes which need to be better defined in subsequent research.

Abstract: In this paper, we provide a comprehensive overview of the state-of-knowledge of dust flux and variability in time and space in different sectors of East Antarctica during the Holocene. By integrating the literature data with new evidences, we discuss the dust flux and grain-size variability during the current interglacial and its provenance in the innermost part of the East Antarctic plateau as well as in peripheral regions located close to the Transantarctic Mountains. The local importance of aeolian mineral dust aerosol deflated from low-elevation areas of peripheral East Antarctica is also discussed in the light of new data from several coastal, low-elevation sites.

Abstract: In this study we map the entire East African Rift System (EARS) within a global surface-wave velocity model to better constrain the structure of the underlying mantle, as well as patterns that might be associated with its continuation in the Mozambique Channel. We use all publicly available seismograms from the African continent, amounting to 1296 stations and more than 30 years of recordings. From these data, we obtain dispersion curves using both ambient noise and teleseismic earthquakes. To our measurements, we add global counterparts and jointly invert them for phase-velocity maps. We exploit a linearized inversion based on the ray theory, with an adaptive parameterization that allows for maximizing the resolution of the final maps based on the density of data coverage. We thus image the main African cratons and also some of the Archean blocks within them. We highlight the discontinuous nature of magmatic activity along the EARS and also display low-velocity anomalies beneath the Comores Archipelago, Madagascar and Bassas da India volcanic islands and seamounts. This last low-velocity anomaly is in the direct continuation of the EARS and could unveil an important magmatic system in the Mozambique Channel.