Erosion rates and patterns in a transient landscape, Grand Staircase, southern Utah, USA

Geology ◽  
2019 ◽  
Vol 47 (9) ◽  
pp. 811-814 ◽  
Author(s):  
Kerry E. Riley ◽  
Tammy M. Rittenour ◽  
Joel L. Pederson ◽  
Patrick Belmont
Keyword(s):  
Grand Canyon ◽  
Climatic Forcing ◽  
Sediment Storage ◽  
Erosion Rates ◽  
Base Level ◽  
Rock Types ◽  
Alluvial Sediment ◽  
Dynamic Landscapes ◽  
Cosmogenic 10Be

AbstractCosmogenic 10Be concentrations in alluvial sediment are widely used to infer long-term, catchment-averaged erosion rates based on the assumption that the landscape is in mass-flux steady state. However, many landscapes are out of equilibrium over millennial time scales due to tectonic and climatic forcing. The Grand Staircase of the Colorado Plateau (North America) is a transient landscape, adjusting to base-level fall from the carving of the Grand Canyon, and is characterized by cliff-bench topography caused by differential erosion of lithologic units. The 10Be concentrations from 52 alluvial and colluvial samples, collected in nested fashion from five catchments, produced inferred erosion rates ranging from 20 to >3500 m/m.y. (or mm/k.y.). We attribute this high variance in part to lithologic-controlled steepness and hotspots of erosion related to cliff retreat along the White Cliffs (escarpment near Mt. Carmel Junction, Utah), as well as headward drainage expansion along the uppermost Pink Cliffs (escarpment within Bryce Canyon National Park). Results from the downslope Vermillion Cliffs (near Kanab) indicate lower erosion rates despite similar slope and rock types, suggesting knick-zone migration has passed that lower region of our study area. The 10Be concentrations measured along trunk streams systematically match local, subcatchment erosion rates, with muted influence from upstream sediment sources. This is consistent with intermittent sediment conveyance between cliff and bench terrain, with sediment storage and localized release associated with ephemeral arroyo systems in the region. Therefore, while detrital cosmogenic nuclide records in transient landscapes may not directly reflect upstream catchment-averaged erosion rates, 10Be inventories can provide insight into unsteady upslope-directed erosion and downslope-directed sediment conveyance in these dynamic landscapes.

scholarly journals Building mountain biodiversity: Geological and evolutionary processes

Science ◽  
2019 ◽  
Vol 365 (6458) ◽  
pp. 1114-1119 ◽  
Author(s):  
Carsten Rahbek ◽  
Michael K. Borregaard ◽  
Alexandre Antonelli ◽  
Robert K. Colwell ◽  
Ben G. Holt ◽  
...  
Keyword(s):  
Regional Climate ◽  
Ecological Processes ◽  
Evolutionary Mechanisms ◽  
Deep Time ◽  
Nutrient Runoff ◽  
Tropical Mountains ◽  
Rock Types ◽  
Dynamic Landscapes ◽  
Speciation Rates

Mountain regions are unusually biodiverse, with rich aggregations of small-ranged species that form centers of endemism. Mountains play an array of roles for Earth’s biodiversity and affect neighboring lowlands through biotic interchange, changes in regional climate, and nutrient runoff. The high biodiversity of certain mountains reflects the interplay of multiple evolutionary mechanisms: enhanced speciation rates with distinct opportunities for coexistence and persistence of lineages, shaped by long-term climatic changes interacting with topographically dynamic landscapes. High diversity in most tropical mountains is tightly linked to bedrock geology—notably, areas comprising mafic and ultramafic lithologies, rock types rich in magnesium and poor in phosphate that present special requirements for plant physiology. Mountain biodiversity bears the signature of deep-time evolutionary and ecological processes, a history well worth preserving.

Spatially Averaged Long-Term Erosion Rates Measured from in Situ-Produced Cosmogenic Nuclides in Alluvial Sediment

1996 ◽  
Vol 104 (3) ◽  
pp. 249-257 ◽  
Author(s):  
Darryl E. Granger ◽  
James W. Kirchner ◽  
Robert Finkel
Keyword(s):  
Cosmogenic Nuclides ◽  
Erosion Rates ◽  
Alluvial Sediment

Late Holocene Paleoecology and Sedimentary History of a Small Lowland Catchment in Central England

1985 ◽  
Vol 24 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Antony G. Brown ◽  
Keith E. Barber
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Structural Damage ◽  
Late Holocene ◽  
Sediment Storage ◽  
Erosion Rates ◽  
History Of ◽  
Floodplain Deposits ◽  
Floodplain Sediments

A variety of paleoecological and sedimentary techniques were used to investigate the storage of sediment within a small lowland catchment during the Holocene. Radiocarbon dating of vertically accreted floodplain deposits allowed the calculation of inorganic accumulation rates. These rates show a dramatic increase in sediment deposition during the late Bronze Age and early Iron Age (2900-2300 yr B.P.) due to deforestation and cultivation of the catchment slopes and resultant soil erosion. The soils within the catchment were susceptible to structural damage, surface waterlogging, and slope-wash erosion. From the calculated increases in sediment storage estimates of catchment erosion were made which vary from around 20 to 140 tons km−2 yr−1. The study of alluvial chronology at this scale can provide unique information on the source areas of Holocene floodplain sediments and provide long-term erosion rates.

scholarly journals Long-term flood controls on semi-arid river form: evidence from the Sabie and Olifants rivers, eastern South Africa

2015 ◽  
Vol 367 ◽  
pp. 141-146 ◽  
Author(s):  
G. Heritage ◽  
S. Tooth ◽  
N. Entwistle ◽  
D. Milan
Keyword(s):  
South Africa ◽  
Riparian Vegetation ◽  
Optically Stimulated Luminescence ◽  
Primary Control ◽  
Sediment Storage ◽  
Alluvial Sediment ◽  
Extreme Flood ◽  
Bedrock Erosion ◽  
Morphologic Development

Abstract. Rivers in the Kruger National Park, eastern South Africa, are characterised by bedrock-influenced "macrochannels" containing variable alluvial thicknesses and riparian vegetation assemblages. Evidence from the Sabie and Olifants rivers suggests that flows up to moderate floods (<3500 m3 s−1) tend to result in net alluviation, with sediments gradually covering the underlying bedrock. More extreme floods strip alluvium and erode bedrock, effectively exerting the primary control over long-term river morphologic development. On the Olifants River, post-flood aerial LIDAR imagery reveals that the 2012 extreme flood (~14000 m3 s−1) resulted in extensive stripping of stored alluvial sediment, exposing and eroding the underlying weathered bedrock. On the Sabie River, preliminary optically stimulated luminescence ages for remnant alluvium are all less than 1000 years, highlighting typical timescales of sediment storage. Together, these results suggest that while periods of general alluviation occur on these systems, long-term river development results from extreme flood-generated bedrock erosion.

MAPPING THE COLORADO RIVER IN GRAND CANYON TO DIRECTLY MEASURE LONG-TERM CHANGES IN SEDIMENT STORAGE

2018 ◽  
Author(s):  
Matt Kaplinski ◽  
◽  
Paul E. Grams ◽  
Josepth E. Hazel ◽  
Daniel D. Buscombe ◽  
...  
Keyword(s):  
Colorado River ◽  
Grand Canyon ◽  
Sediment Storage ◽  
Long Term Changes

scholarly journals Soil erosion by snow gliding – a first quantification attempt in a subalpine area in Switzerland

2014 ◽  
Vol 18 (9) ◽  
pp. 3763-3775 ◽  
Author(s):  
K. Meusburger ◽  
G. Leitinger ◽  
L. Mabit ◽  
M. H. Mueller ◽  
A. Walter ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Land Cover ◽  
Sediment Yield ◽  
Soil Loss ◽  
Water Erosion ◽  
Erosion Rates ◽  
The Difference ◽  
Snow Gliding

Abstract. Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959–2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha−1 yr−1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha−1 yr−1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2 = 0.64; p < 0.005) and to the snow deposition sediment yields (R2 = 0.39; p = 0.13). The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based on these results, we conclude that snow gliding appears to be a crucial and non-negligible process impacting soil erosion patterns and magnitude in subalpine areas with similar topographic and climatic conditions.

scholarly journals MATLAB Virtual Toolbox for Retrospective Rockfall Source Detection and Volume Estimation Using 3D Point Clouds: A Case Study of a Subalpine Molasse Cliff

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 75
Author(s):  
Dario Carrea ◽  
Antonio Abellan ◽  
Marc-Henri Derron ◽  
Neal Gauvin ◽  
Michel Jaboyedoff
Keyword(s):  
Point Cloud ◽  
Natural Hazard ◽  
Point Clouds ◽  
Volume Estimation ◽  
Natural Phenomena ◽  
Frequency Distributions ◽  
Erosion Rates ◽  
3D Point Clouds

The use of 3D point clouds to improve the understanding of natural phenomena is currently applied in natural hazard investigations, including the quantification of rockfall activity. However, 3D point cloud treatment is typically accomplished using nondedicated (and not optimal) software. To fill this gap, we present an open-source, specific rockfall package in an object-oriented toolbox developed in the MATLAB® environment. The proposed package offers a complete and semiautomatic 3D solution that spans from extraction to identification and volume estimations of rockfall sources using state-of-the-art methods and newly implemented algorithms. To illustrate the capabilities of this package, we acquired a series of high-quality point clouds in a pilot study area referred to as the La Cornalle cliff (West Switzerland), obtained robust volume estimations at different volumetric scales, and derived rockfall magnitude–frequency distributions, which assisted in the assessment of rockfall activity and long-term erosion rates. An outcome of the case study shows the influence of the volume computation on the magnitude–frequency distribution and ensuing erosion process interpretation.

Millennial scale variability of denudation rates for the last 15 kyr inferred from the detrital 10Be record of Lake Stappitz in the Hohe Tauern massif, Austrian Alps

The Holocene ◽  
2017 ◽  
Vol 27 (12) ◽  
pp. 1914-1927 ◽  
Author(s):  
Reto Grischott ◽  
Florian Kober ◽  
Maarten Lupker ◽  
Juergen M Reitner ◽  
Ruth Drescher-Schneider ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Anthropogenic Impacts ◽  
Sediment Cores ◽  
Tight Coupling ◽  
Climatic Forcing ◽  
Erosion Rates ◽  
Austrian Alps ◽  
Denudation Rates ◽  
Time Period ◽  
Flooding Events

Reconstructing paleo-denudation rates over Holocene timescales in an Alpine catchment provides a unique opportunity to isolate the climatic forcing of denudation from other tectonic or anthropogenic effects. Cosmogenic 10Be on two sediment cores from Lake Stappitz (Austrian Alps) were measured yielding a 15-kyr-long catchment-averaged denudation record of the upstream Seebach Valley. The persistence of a lake at the outlet of the valley fixed the baselevel, and the high mean elevation minimizes anthropogenic impacts. The 10Be record indicates a decrease in the proportion of paraglacial sediments from 15 to 7 kyr cal. BP after which the 10Be concentrations are considered to reflect hillslope erosion and thus can be converted to denudation rates. These ones significantly fluctuated over this time period: lower hillslope erosion rates of ca. 0.4 mm/year dated between 5 and 7 kyr cal. BP correlate with a stable climate, sparse flooding events and elevated temperatures that favoured the widespread growth of stabilizing soils and vegetation. Higher hillslope erosion rates of ca. 0.8 mm/year over the last ~4 kyr correlate with a variable, cooler climate where frequent flooding events enhance denudation of less protected hillslopes. Overall, our results suggest a tight coupling of climate and hillslope erosion in alpine landscapes as it has been observed in other parts of the Alps.

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