Mass Wasting on the Moon: Implications for Seismicity

Introduction: Seismicity estimates play an important role in creating regional geological characterizations, which are useful for understanding a planet's formation and evolution, and of key importance to site selection for landed missions. Here we investigate the regional effects of lunar seismicity with the goal of determining whether surface features such as landslides and boulder trails on the Moon are triggered by fault motion

The influence of sediment cover variability on long-term river incision rates: An example from the Peikang River, central Taiwan

[1] This study explores the hypothesis that the relative frequency of rock exposure in the bed of an incising channel can have a first-order impact on the long-term average erosion rate. The 1999 Chi-Chi earthquake in central Taiwan generated thousands of landslides along the middle reach of the Peikang River. Sediment from these landslides produced widespread aggradation, such that much of the river's bed remains shielded from active bedrock incision. We present data that constrain the spatial and temporal variability of sediment cover for the Peikang River. Because the river is undergoing spatially variable Holocene bedrock incision (1-10 mm/yr), it offers a unique natural experiment to test the influence of intermittent sedimentation on long-term incision rates. Published electrical resistivity surveys at seven locations along the river reveal median sediment depth values ranging from 1.9 to 11.5 m. The sediment depth correlates inversely with long-term incision rate and sediment transport capacity. We interpret this as an indication that the frequency of bedrock exposure exerts a major influence on incision along the Peikang River

Linking Taiwan's subcritical Hsuehshan Range topography and foreland basin architecture

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95204/1/tect2249.pd

Modelling localized sources of sediment in mountain catchments for provenance studies

A hydrology–sediment modelling framework based on the model Topkapi‐ETH combined with basin geomorphic mapping is used to investigate the role of localized sediment sources in a mountain river basin (Kleine Emme, Switzerland). The periodic sediment mobilization from incised areas and landslides by hillslope runoff and river discharge is simulated in addition to overland flow erosion to quantify their contributions to suspended sediment fluxes. The framework simulates the suspended sediment load provenance at the outlet and its temporal dynamics, by routing fine sediment along topographically driven pathways from the distinct sediment sources to the outlet. We show that accounting for localized sediment sources substantially improves the modelling of observed sediment concentrations and loads at the outlet compared to overland flow erosion alone. We demonstrate that the modelled river basin can shift between channel‐process and hillslope‐process dominant behaviour depending on the model parameter describing gully competence on landslide surfaces. The simulations in which channel processes dominate were found to be more consistent with observations, and with two independent validations in the Kleine Emme, by topographic analysis of surface roughness and by sediment tracing with 10Be concentrations. This research shows that spatially explicit modelling can be used to infer the dominant sediment production process in a river basin, to inform and optimize sediment sampling strategies for denudation rate estimates, and in general to support sediment provenance studies. © 2020 John Wiley & Sons, Ltd.ISSN:0197-9337ISSN:1096-983

Biodiversity and Topographic Complexity: Modern and Geohistorical Perspectives

Topographically complex regions on land and in the oceans feature hotspots of biodiversity that reflect geological influences on ecological and evolutionary processes. Over geologic time, topographic diversity gradients wax and wane over millions of years, tracking tectonic or climatic history. Topographic diversity gradients from the present day and the past can result from the generation of species by vicariance or from the accumulation of species from dispersal into a region with strong environmental gradients. Biological and geological approaches must be integrated to test alternative models of diversification along topographic gradients. Reciprocal illumination among phylogenetic, phylogeographic, ecological, paleontological, tectonic, and climatic perspectives is an emerging frontier of biogeographic research

Biodiversity and Topographic Complexity: Modern and Geohistorical Perspectives

Topographically complex regions on land and in the oceans feature hotspots of biodiversity that reflect geological influences on ecological and evolutionary processes. Over geologic time, topographic diversity gradients wax and wane over millions of years, tracking tectonic or climatic history. Topographic diversity gradients from the present day and the past can result from the generation of species by vicariance or from the accumulation of species from dispersal into a region with strong environmental gradients. Biological and geological approaches must be integrated to test alternative models of diversification along topographic gradients. Reciprocal illumination among phylogenetic, phylogeographic, ecological, paleontological, tectonic, and climatic perspectives is an emerging frontier of biogeographic research. Topographically complex regions today feature high taxonomic and ecological diversity. Ancient topographic diversity gradients arose and declined over millions of years. Paleontological and modern data are crucial to understand topographic diversity gradients. Topographically complex regions have high conservation valu