This week in Nature Geoscience, Michael Lamb and Mark Fonstad report the incision of Canyon Lake Gorge, Texas, during a single dam-release flood event in 2002. This well-constrained flood event moved metre-sized boulders, excavated ~7m of limestone and transformed a soil-mantled valley into a bedrock canyon in only ~3days! Not quite a natural flood event, but quite spectacular and informative all the same. View Canyon Lake in Google Earth here.
- Jaumann et al. describe multiple erosional events across 2.8 billion years, driven by very intermittent flow from multiple water sources, in the The Western Libya Montes Valley System
- Erkeling et al. report a similarly multi-genetic evolution of valley networks in the eastern Libya Montes, formed by a combination of surface runoff and groundwater-induced processes over ~800 million years
- Head et al. discuss evidence for debris-covered glaciers operating in the Late Amazonian period
- Dickson et al. take a detailed look at crater morphology at the Phlegra Montes (specifically overtopping by ice) to reveal occupation by ice 1 km thick in the Late Amazonian
- Kneissl et al. describe a detailed analysis of the distribution and orientation of gullies on the Martian surface, which revealed that formation mechanisms based on atmospheric water-ice deposition are more likely than processes related to groundwater flow
- Levy et al. contribute to the ongoing debate over the origin of gullies on Mars - dry granular flows and landslides, wet debris flows, or fluvial erosion and alluvial deposition? Their detailed morphological analysis of lobate structures in Protonilus Mensae indicates these at least were formed by wet debris flows
- Kleinhans et al. detail a simple numerical model for alluvial fan and delta development that indicates that features seen on Mars result from single flow events lasting days to years.
Simon's review paper, "Tectonics and geomorphology", has just been published in Progress in Physical Geography. The review attempts to summarise the status of fluvial, hillslope, glacial and submarine geomorphology in relation to active tectonics (at the time of writing). This means both attempts to use geomorphology to infer something about the tectonics, and exploiting active tectonics settings to further our understanding of geomorphological processes. The article is part of a special volume of Progress in Physical Geography on the future of geomorphology, which also contains a number of other interesting articles.
Please email Simon if you are unable to access the article.