Bedload transport in a formerly glaciated mountain catchment constrained by particle tracking
Summary: The paper assesses bedload transport in a formerly glaciated high-mountain basin by means of a virtual velocities approach. Virtual velocities were derived by surveying tracers movement over a 3-year study period. Tracers were deployed in two contrasting sites, a fluvially dominated hanging valley and a downstream relict glacial trough where periodic colluvial sediment inputs from tributaries are experienced. We also investigate contribution given to bedload transport by rainfall and snowmelt.
Earth Surf. Dynam., 3, 527-542, doi:10.5194/esurf-3-527-2015, 2015
Spatial distributions of earthquake-induced landslides and hillslope preconditioning in the northwest South Island, New Zealand
Summary: Large earthquakes commonly trigger widespread and destructive landsliding. This paper tests the hypothesis that spatial distributions of earthquake-induced landslides are determined by both the conditions at the time of the triggering earthquake and the legacy of past events. Our findings emphasise that a lack of understanding of the legacy of damage in hillslopes potentially represents an important source of uncertainty when assessing regional landslide susceptibility.
Earth Surf. Dynam., 3, 501-525, doi:10.5194/esurf-3-501-2015, 2015
Topographic roughness as a signature of the emergence of bedrock in eroding landscapes
Summary: Rock is exposed at the Earth surface when erosion rates locally exceed rates of soil production. This transition is marked by a diagnostic increase in topographic roughness, which we demonstrate can be a powerful indicator of the location of rock outcrop in a landscape. Using this to explore how hillslopes in two landscapes respond to increasing erosion rates, we find that the transition from soil-mantled to bedrock hillslopes is patchy and spatially heterogeneous.
Earth Surf. Dynam., 3, 483-499, doi:10.5194/esurf-3-483-2015, 2015
The periglacial engine of mountain erosion – Part 2: Modelling large-scale landscape evolution
Summary: We incorporate relations between climate, sediment thickness and periglacial processes quantified in the accompanying paper into a landscape evolution model. This allows us to time-integrate the periglacial contribution to mountain topography on million-year time scales. It is a robust result of our simulations that periglacial processes lead to topographic smoothing. Owing to the climate dependency, this smoothing leads to formation of low-relief surfaces at altitudes controlled by temperature.
Earth Surf. Dynam., 3, 463-482, doi:10.5194/esurf-3-463-2015, 2015
The periglacial engine of mountain erosion – Part 1: Rates of frost cracking and frost creep
Summary: An increasing number of studies demonstrates links between the intensity of periglacial processes and bedrock erosion in steep mountain landscapes. Here, we quantify the dependence of periglacial processes on temperature and sediment thickness. This allows us to model frost processes across the full range of settings encountered in mountain landscapes. We find that sediment mantle thickness strongly modulates the relation between climate and periglacial weathering and sediment transport.
Earth Surf. Dynam., 3, 447-462, doi:10.5194/esurf-3-447-2015, 2015