Drainage divide networks – Part 1: Identification and ordering in digital elevation models Earth Surface Dynamics DOI 10.5194/esurf-8-245-2020 30 April 2020 Drainage divides are believed to provide clues about divide migration and the instability of landscapes. Here, we present a novel approach to extract drainage divides from digital elevation models and to order them in a drainage divide network. We present our approach by studying natural and artificial landscapes generated with a landscape evolution model and disturbed to induce divide migration. Read more
Seismic location and tracking of snow avalanches and slush flows on Mt. Fuji, Japan Earth Surface Dynamics DOI 10.5194/esurf-7-989-2019 15 November 2019 Avalanches and slush flows from Mt. Fuji are a major natural hazard as they may attain run-out distances of up to 4 km and destroy parts of the forest and infrastructure. We located and tracked them for the first time using seismic data. Numerical simulations were conducted to assess the precision of the seismic tracking. We also inferred dynamical properties characterizing these hazardous mass movements. This information is indispensable for assessing avalanche risk in the Mt. Fuji region. Read more
Mapping landscape connectivity as a driver of species richness under tectonic and climatic forcing Earth Surface Dynamics DOI 10.5194/esurf-7-895-2019 1 October 2019 Mountainous landscapes have long been recognized as potential drivers for genetic drift, speciation, and ecological resilience. We present a novel approach that can be used to assess and quantify drivers of biodiversity, speciation, and endemism over geological time. Using coupled climate–landscape models, we show that biodiversity under tectonic and climatic forcing relates to landscape dynamics and that landscape complexity drives species richness through orogenic history. Read more
A global delta dataset and the environmental variables that predict delta formation on marine coastlines Earth Surface Dynamics DOI 10.5194/esurf-7-773-2019 26 August 2019 River deltas are valuable resources that support biodiversity and human habitation. Despite this we do not have a global census of deltas nor do we know the conditions that promote their formation. We surveyed 5399 river mouths greater than 50 m wide and found that 2174 (40%) create a delta. The conditions that lead to delta formation are high sediment input and low wave and tide conditions. These results can be used to understand how deltas will adapt to environmental changes. Read more
Evaluating post-glacial bedrock erosion and surface exposure duration by coupling in situ optically stimulated luminescence and 10Be dating Earth Surface Dynamics DOI 10.5194/esurf-7-633-2019 11 July 2019 Assessing the impact of glaciation at the Earth’s surface requires simultaneous quantification of the impact of climate variability on past glacier fluctuations and on bedrock erosion. Here we present a new approach for evaluating post-glacial bedrock surface erosion in mountainous environments by combining two different surface exposure dating methods. This approach can be used to estimate how bedrock erosion rates vary spatially and temporally since glacier retreat in an alpine environment. Read more
Alluvial channel response to environmental perturbations: fill-terrace formation and sediment-signal disruption Earth Surface Dynamics DOI 10.5194/esurf-7-609-2019 1 July 2019 We performed seven physical experiments to explore terrace formation and sediment export from a braided alluvial river system that is perturbed by changes in water discharge, sediment supply, or base level. Each perturbation differently affects (1) the geometry of terraces and channels, (2) the timing of terrace formation, and (3) the transient response of sediment discharge. Our findings provide guidelines for interpreting fill terraces and sediment export from fluvial systems. Read more
Long-term erosion of the Nepal Himalayas by bedrock landsliding: the role of monsoons, earthquakes and giant landslides Earth Surface Dynamics DOI 10.5194/esurf-7-107-2019 25 January 2019 We mapped eight monsoon-related (> 100 m2) and large (> 0.1 km2) landslides in the Nepal Himalayas since 1970. Adding inventories of Holocene landslides, giant landslides (> 1 km3), and landslides from the 2015 Gorkha earthquake, we constrain the size–frequency distribution of monsoon- and earthquake-induced landslides. Both contribute ~50 % to a long-term (> 10 kyr) total erosion of ~2 mm yr-1, matching the long-term exhumation rate. Large landslides rarer than10Be sampling time drive erosion. Read more
On the Holocene evolution of the Ayeyawady megadelta Earth Surface Dynamics DOI 10.5194/esurf-6-451-2018 12 June 2018 Here we provide the first results on the evolution of the Ayeyarwady delta, the last unstudied megadelta of Asia. In addition to its intrinsic value as a founding study on the Holocene development of this region, we advance new ideas on the climate control of monsoonal deltas as well as describe for the first time a feedback mechanism between tectonics and tidal hydrodynamics that can explain the peculiarities of the Ayeyarwady delta. Read more
Glacial isostatic adjustment modelling: historical perspectives, recent advances, and future directions Earth Surface Dynamics DOI 10.5194/esurf-6-401-2018 29 May 2018 This article is a contribution to a special issue onTwo centuries of modelling across scales. It describes the historical observations, evolving hypotheses, and early calculations that led to the development of the field of glacial isostatic sdjustment (GIA) modelling, which seeks to understand feedbacks between ice-sheet change, sea-level change, and solid Earth deformation. Recent and future advances are discussed. Future progress will likely involve an interdisciplinary approach. Read more
Colluvial deposits as a possible weathering reservoir in uplifting mountains Earth Surface Dynamics DOI 10.5194/esurf-6-217-2018 21 March 2018 The role of mountain uplift and associated silicate weathering in the global climate over geological times is controversial. Previous soil column models suggest that weathering falls at a high denudation rate. We present the results of a 3-D model that couples erosion and weathering, a CO2consumer during mountain uplift. Our model suggests that the weathering of temporarily stocked colluvium may contribute significantly to the mountain weathering outflux at high denudation rates. Read more