Surface exposure dating of the Great Aletsch Glacier Egesen moraine system, western Swiss Alps, using the cosmogenic nuclide10Be

2004 ◽  
Vol 19 (5) ◽  
pp. 431-441 ◽  
Author(s):  
Meredith A. Kelly ◽  
Peter W. Kubik ◽  
Friedhelm Von Blanckenburg ◽  
Christian SchlÜchter
Keyword(s):  
Swiss Alps ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Western Swiss Alps

Reconstructing the Timing of Flash Floods Using 10Be Surface Exposure Dating at Leidy Creek Alluvial Fan and Valley, White Mountains, California–Nevada, USA

2015 ◽  
Vol 83 (1) ◽  
pp. 178-186 ◽  
Author(s):  
Markus Fuchs ◽  
Rebecca Reverman ◽  
Lewis A. Owen ◽  
Kurt L. Frankel
Keyword(s):  
Flash Floods ◽  
Alluvial Fan ◽  
Optically Stimulated Luminescence ◽  
Alluvial Fans ◽  
White Mountains ◽  
The Holocene ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Outburst Floods ◽  
Glacial Lake Outburst Floods

AbstractLarge alluvial fans characterize the piedmonts of the White Mountains, California–Nevada, USA, with large boulders strewn across their surfaces. The boulders are interpreted as flash floods deposits with an unclear trigger for the transport process. Several triggers are possible, including glacial lake outburst floods (GLOFs), thunderstorms or rainfall on snow cover. From a paleoenvironmental perspective, the origin of the flash floods is of fundamental importance. The alluvial fans that flank the White Mountains at Leidy Creek display particularly impressive examples of these deposits. The boulder deposits and the source catchment at Leidy Creek were examined using 10Be terrestrial cosmogenic nuclide (TCN) surface exposure dating to help elucidate their age and origin. All boulders dated on the alluvial fans date to the Holocene. This is in accordance with the geomorphic analyses of the Leidy Creek catchment and its terraces and sediment ridges, which were also dated to the Holocene using optically stimulated luminescence (OSL) and 10Be surface exposure. The results suggest that the boulders on the alluvial fan were deposited by flash floods during thunderstorm events affecting the catchment of the Leidy Creek valley. Paleomonsoonal-induced mid-Holocene flash floods are the most plausible explanation for the discharges needed for these boulder aggradations, but a regional dataset is needed to confirm this explanation.

scholarly journals A zero-exposure time test on an erratic boulder: evaluating the problem of pre-exposure in Surface Exposure Dating

2009 ◽  
Vol 58 (1) ◽  
pp. 1-11
Author(s):  
Lucia A. Abbühl ◽  
Naki Akcar ◽  
Stefan Strasky ◽  
Angela A. Graf ◽  
Susan Ivy-Ochs ◽  
...  
Keyword(s):  
Exposure Time ◽  
Prior Exposure ◽  
Lateral Moraine ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Three Samples ◽  
Time Test ◽  
The Right ◽  
Geometric Relationship ◽  
Erratic Boulder

Abstract. The method of surface exposure dating using in-situ produced cosmogenic nuclides has become an important and widely applied tool in Quaternary science. One application is the dating of erratic boulders on moraines. An important problem however remains: the evaluation of potential pre-exposure time for samples from boulder surfaces. We have tested pre-exposure by sampling all sides of a recently exposed boulder in order to measure inherited nuclides from prior exposure periods. The sampled erratic boulder rests on the right lateral moraine of the most recent advance of the Glacier de Tsijiore Nouve in the Arolla Valley, Switzerland. Mapping of the area was done to reconstruct the Holocene fluctuations of the glacier. This glacier is especially useful for such a test as it is characterized by an ideal geometric relationship between accumulation and ablation area and, therefore, responds rapidly to mass-balance changes. The sampled boulder was deposited in 1991. Assuming no prior exposure the expected concentration of a given cosmogenic nuclide should be near zero. The 10Be/9Be ratios of the five measured samples were indistinguishable from blank values within the given errors, demonstrating that the samples did not experience pre-exposure. Three samples measured for 21Ne reveal 21Ne/20Ne and 22Ne/20Ne ratios similar to those of air, with no detectable prior cosmogenic Ne accumulation.

scholarly journals Multiscale Very-High Resolution Topographic Models in Alpine Ecology: Pros and Cons of Airborne LiDAR and Drone-Based Stereo-Photogrammetry Technologies

2021 ◽  
Author(s):  
Annie S. Guillaume ◽  
Kevin Leempoel ◽  
Estelle Rochat ◽  
Aude Rogivue ◽  
Michel Kasser ◽  
...  
Keyword(s):  
Species Distribution Modelling ◽  
Airborne Lidar ◽  
Swiss Alps ◽  
The Arctic ◽  
Site Characteristics ◽  
Digital Elevation ◽  
Stereo Photogrammetry ◽  
Arabis Alpina ◽  
Western Swiss Alps ◽  
Very High

The vulnerability of alpine environments to climate change presses an urgent need to accurately model and understand these ecosystems. Popularity in use of digital elevation models (DEMs) to derive proxy environmental variables has increased over the past decade, particularly as DEMs are relatively cheaply acquired at very high resolutions (VHR; <1m spatial resolution). Here, we implement a multiscale framework and compare DEM-derived variables produced by Light Detection and Ranging (LiDAR) and stereo-photogrammetry (PHOTO) methods, with the aims of assessing their relevance and utility in species distribution modelling (SDM). Using a case study on the arctic-alpine plant Arabis alpina in two valleys in the western Swiss Alps, we show that both LiDAR and PHOTO technologies can be relevant for producing DEM-derived variables for use in SDMs. We demonstrate that PHOTO DEMs rivalled the accuracy of LiDAR, putting the current paradigm of LiDAR being the more accurate of the two methods into question. We obtained DEMs at spatial resolutions of 6.25cm-8m for PHOTO and 50cm-32m for LiDAR, where we determined that the optimal spatial resolutions of DEM-derived variables in SDM were between 1 and 32m, depending on the variable and site characteristics. We found that the reduced extent of PHOTO DEMs altered the calculations of all derived variables, which had particular consequences on their relevance at the site with heterogenous terrain. However, for the homogenous site, we found that SDMs based on PHOTO-derived variables generally had higher predictive powers than those derived from LiDAR at matching resolutions. From our results, we recommend carefully considering the required DEM extent to produce relevant derived variables. We also advocate implementing a multiscale framework to appropriately assess the ecological relevance of derived variables, where we caution against the use of VHR-DEMs finer than 50cm in such studies.

scholarly journals Influence of microclimate and geomorphological factors on alpine vegetation in the Western Swiss Alps

2019 ◽  
Vol 44 (15) ◽  
pp. 3093-3107 ◽  
Author(s):  
Elisa Giaccone ◽  
Miska Luoto ◽  
Pascal Vittoz ◽  
Antoine Guisan ◽  
Grégoire Mariéthoz ◽  
...  
Keyword(s):  
Swiss Alps ◽  
Alpine Vegetation ◽  
Western Swiss Alps

scholarly journals Surface Exposure Dating and Geophysical Tomography of the Royal Arches Meadow Rock Avalanche, Yosemite Valley, California

2020 ◽  
Vol 8 ◽  
Author(s):  
Marcus Pacheco ◽  
Alain M. Plattner ◽  
Greg M. Stock ◽  
Dylan H. Rood ◽  
Christopher J. Pluhar
Keyword(s):  
Rock Avalanche ◽  
Surface Exposure Dating ◽  
Exposure Dating ◽  
Yosemite Valley ◽  
Geophysical Tomography
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