Scotland's Highlands are tectonically quiescent but have experienced high rates of isostatic uplift in response to deglaciation. To understand the effects of both deglaciation and regional uplift on landscape evolution, we measured the concentration of cosmogenic in situ 14C in river sands collected in Glen Feshie (Cairngorms). Like other terrestrial cosmogenic radionuclides, in situ 14C can be used to calculate basin-wide denudation rates over millennial timescales. 14C has a short half-life relative to other in situ cosmogenic radionuclides, giving it an advantage in post-glacial landscapes: Very little 14C will be inherited from exposure before glaciation of the landscape, meaning that concentrations will reflect sediment production and transport dominantly in the Holocene. When we calculate denudation rates based on the common assumption of basin-wide homogeneity of erosion, we find no correlation between topographic metrics such as the normalised channel steepness index and inferred denudation rates, which range between 0.175 and 1.356 mm/year. Based on field and remote sensing observations, we suggest that 14C becomes diluted downstream due to sediment supply from paraglacial terrace material, and develop a mixing model to test this hypothesis. We identify the terraces that are likely to contribute sediment to the channels through flood modelling, geomorphic mapping and remote sensing observations. Our mixing model indicates that the observed distribution of 14C concentrations can be explained if terrace escarpments have basin-averaged migration distances of 8 to 30 cm during large flood events. This interpretation is consistent with remotely sensed images of channel activity and terrace bank retreat within the catchment. Our results show that paraglacial sediment stores contribute to sediment fluxes in the late Holocene and highlight the on-going glacial legacy on landscape evolution.
A three-dimensional hydraulic-thermal model has been developed for the island of Pantelleria in order to investigate the driving heat transfer mechanisms and the role of rocks and fluids thermal and hydraulic properties in controlling the temperature distribution. The model simulates transient conditions accounting for changes with time of the background steady-state thermal field over a period of 50,000 years, which coincides with a period of major morphological/structural stability on the island. The comparison between observed and computed temperatures was used to validate the model. Model outcomes confirm temperature up to 490 °C at 2 km depth in the central part of the Cinque Denti caldera. The proposed thermal modeling agrees with the trend of the thermal anomaly on the island, clearly evidencing how the center of the thermal anomaly is located within the young caldera, while the north-eastern part of the island is characterized by much lower temperatures than its central-southern part. It is shown that a coupled thermal–hydraulic 3D model can provide a clear perspective on surface and subsurface conditions that drive heat transfer, thus helping to understand the characteristics of geothermal systems in the area.
Magnetic Field Line Curvature Scattering (FLCS) is one of the important loss mechanism for energetic particles, referring to the scattering phenomenon where charged particles experience changes in their pitch angles due to the curvature and non-uniformity of magnetic field. Previous methods evaluating FLCS were suitable for less stretched configurations like dipole magnetic fields, but under Ts05 model, they led to non-physical results, especially in regions where the adiabatic parameter