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

Limited Pliocene/Pleistocene glaciation in Deep Freeze Range, northern Victoria Land, Antarctica, derived from in situ cosmogenic nuclides

2003 ◽  
Vol 15 (4) ◽  
pp. 493-502 ◽  
Author(s):  
PETER OBERHOLZER ◽  
CARLO BARONI ◽  
JOERG M. SCHAEFER ◽  
GIUSEPPE OROMBELLI ◽  
SUSAN IVY OCHS ◽  
...  
Keyword(s):  
Cosmogenic Nuclides ◽  
Dry Valleys ◽  
Climate Regime ◽  
Erosion Rates ◽  
Terra Nova Bay ◽  
New Information ◽  
Victoria Land ◽  
Exposure Ages ◽  
Middle Pliocene

The question of how stable the climate in Antarctica has been during the last few million years compared to the rest of the planet is still controversial. This study attempts to add new information to the discussion by reconstructing the timing and spatial extent of glacial advances in northern Victoria Land over tens of thousands to millions of years. In Terra Nova Bay region, surface exposure ages and erosion rates of glacially rounded bedrock and glacial erratics have been determined using the cosmogenic nuclides 3He, 10Be and 21Ne. Three morphological units have been analysed. They yield minimum ages of 11 to 34 ka, 309 ka, and 2.6 Ma, respectively. Erosion rates were as low as 20 cm Ma−1 since middle Pliocene time. Taking erosion into account, the oldest surface is 5.3 Ma old. Pleistocene glacier advances had considerable extent, reaching up to 780 m above modern ice levels, but have been restricted to the valleys since at least mid-Pliocene. The existence of landscapes of mid-Pliocene age in northern Victoria Land implies that the climatic stability of the McMurdo Dry Valleys is not unique within the Transantarctic Mountains, but rather the expression of a constantly cold and hyperarid climate regime in entire Victoria Land.

scholarly journals Determining erosion rates in Allchar (Macedonia) to revive the lorandite neutrino experiment

2018 ◽  
Vol 474 (2213) ◽  
pp. 20170470 ◽  
Author(s):  
Pieter Vermeesch ◽  
Martin Rittner ◽  
Irene Schimmelpfennig ◽  
Lucilla Benedetti ◽  
ASTER Team
Keyword(s):  
Particle Physics ◽  
Cosmic Ray ◽  
Neutrino Experiment ◽  
Neutrino Detector ◽  
Erosion Rates ◽  
Muons And Neutrinos ◽  
Physics Experiment ◽  
Further Development

205 Tl in the lorandite (TiAsS 2 ) mine of Allchar (Majdan, FYR Macedonia) is transformed to 205 Pb by cosmic ray reactions with muons and neutrinos. At depths of more than 300 m, muogenic production would be sufficiently low for the 4.3 Ma old lorandite deposit to be used as a natural neutrino detector. Unfortunately, the Allchar deposit currently sits at a depth of only 120 m below the surface, apparently making the lorandite experiment technically infeasible. We here present 25 erosion rate estimates for the Allchar area using in situ produced cosmogenic 36 Cl in carbonates and 10 Be in alluvial quartz. The new measurements suggest long-term erosion rates of 100–120 m Ma −1 in the silicate lithologies that are found at the higher elevations of the Majdanksa River valley, and 200–280 m Ma −1 in the underlying marbles and dolomites. These values indicate that the lorandite deposit has spent most of its existence at depths of more than 400 m, sufficient for the neutrinogenic 205 Pb component to dominate the muon contribution. Our results suggest that this unique particle physics experiment is theoretically feasible and merits further development.

scholarly journals Denudation rates derived from spatially-averaged cosmogenic nuclide analysis in Nelson/Tasman catchments, South Island, New Zealand

2021 ◽  
Author(s):  
◽  
Abby Jade Burdis
Keyword(s):  
New Zealand ◽  
Dynamic Environment ◽  
Low Frequency ◽  
Short Term ◽  
Erosion Rates ◽  
Cosmogenic Nuclide ◽  
Denudation Rates ◽  
Conventional Methods

<p>New Zealand’s tectonically and climatically dynamic environment generates erosion rates that outstrip global averages by up to ten times in some locations. In order to assess recent changes in erosion rate, and also to predict future erosion dynamics, it is important to quantify long-term, background erosion. Current research on erosion in New Zealand predominantly covers short-term (100 yrs) erosion dynamics and Myr dynamics from thermochronological proxy data. Without competent medium-term denudation data for New Zealand, it is uncertain which variables (climate, anthropogenic disturbance of the landscape, tectonic uplift, lithological, or geomorphic characteristics) exert the dominant control on denudation in New Zealand. Spatially-averaged cosmogenic nuclide analysis can effectively offer this information by providing averaged rates of denudation on millennial timescales without the biases and limitations of short-term erosion methods.  Basin-averaged denudation rates were obtained in the Nelson/Tasman region, New Zealand, from analysis of concentrations of meteoric ¹⁰Be in silt and in-situ produced ¹⁰Be in quartz. The measured denudation rates integrate over ~2750 yrs (in-situ) and ~1200 yrs (meteoric). Not only do the ¹⁰Be records produce erosion rates that are remarkably consistent with each other, but they are also independent of topographic metrics. Denudation rates range from ~112 – 298 t km⁻² yr⁻¹, with the exception of one basin which is eroding at 600 - 800 t km⁻² yr⁻¹. The homogeneity of rates and absence of a significant correlation with geomorphic or lithological characteristics could indicate that the Nelson/Tasman landscape is in (or approaching) a topographic steady state.  Millennial term (¹⁰Be-derived) denudation rates are more rapid than those inferred from other conventional methods in the same region (~50 – 200 t km⁻² yr⁻¹). This is likely the result of the significant contribution of low frequency, high magnitude erosive events to overall erosion of the region. Both in-situ and meteoric ¹⁰Be analyses have the potential to provide competent millennial term estimates of natural background rates of erosion. This will allow for the assessment of geomorphic-scale impacts such as topography, tectonics, climate, and lithology on rates of denudation for the country where many conventional methods do not. Cosmogenic nuclides offer the ability to understand the response of the landscape to these factors in order to make confident erosion predictions for the future.</p>

scholarly journals Influence of topography and human activity on erosion in Yunnan, SW China

2016 ◽  
Author(s):  
Amanda H. Schmidt ◽  
Thomas B. Neilson ◽  
Paul R. Bierman ◽  
Dylan H. Rood ◽  
William B. Ouimet ◽  
...  
Keyword(s):  
Land Use ◽  
Human Activity ◽  
River Sediment ◽  
Agricultural Land ◽  
Erosion Rates ◽  
The North ◽  
Small Watersheds ◽  
Basin Area

Abstract. In order to understand better if and where long-term erosion rates calculated using in situ 10Be are affected by contemporary changes in land use and attendant deep regolith erosion, we calculated erosion rates using measurements of in situ 10Be in quartz from 52 samples of river sediment collected from three tributaries of the Mekong River (median basin area = 46.5 km2). Erosion rates range from 12–209 mm/kyr with an area-weighted mean of 117 ± 49 mm/kyr (1 standard deviation) and median of 74 mm/kyr. We observed a decrease in the relative influence of human activity from our steepest and least altered watershed in the north to the most heavily altered landscapes in the south. In the areas of the landscape least disturbed by humans, erosion rates correlate best with measures of topographic steepness. In the most heavily altered landscapes, measures of modern land use correlate with 10Be-estimated erosions rates but topographic steepness parameters cease to correlate with erosion rates. We conclude that in some small watersheds we sampled, those with high rates and intensity of agricultural land use, that tillage and resultant erosion has excavated deeply enough into the regolith to deliver subsurface sediment to streams and thus raise apparent in situ 10Be-derived erosion rates by as much as 2.5 times over background rates had the watersheds not been disturbed.

Large-scale erosion rates from in situ-produced cosmogenic nuclides in European river sediments

2001 ◽  
Vol 188 (3-4) ◽  
pp. 441-458 ◽  
Author(s):  
M. Schaller ◽  
F. von Blanckenburg ◽  
N. Hovius ◽  
P.W. Kubik
Keyword(s):  
Large Scale ◽  
River Sediments ◽  
Cosmogenic Nuclides ◽  
Erosion Rates

Examining erosion in New Zealand over millennial timescales using in-situ 10Be and 14C

2020 ◽  
Author(s):  
Duna Roda-Boluda ◽  
Taylor Schilgen ◽  
Maarten Lupker ◽  
Wittmann Hella ◽  
Prancevic Jeff ◽  
...  
Keyword(s):  
New Zealand ◽  
Erosion Rate ◽  
Sediment Flux ◽  
Short Term ◽  
Sediment Fluxes ◽  
Landslide Activity ◽  
Erosion Rates ◽  
Order Of Magnitude

&lt;p&gt;Landslides are the major erosional process in many orogens, and one of the most sensitive erosional process to tectonic and climatic perturbations. However, it remains extremely difficult to constrain long-term or past rates of landslide activity, and hence their contribution to long-term landscape evolution and catchment sediment fluxes, because the physical records of landsliding are often removed in &lt;10&lt;sup&gt;2&lt;/sup&gt; yrs. Here, we use the in-situ &lt;sup&gt;10&lt;/sup&gt;Be and in-situ &lt;sup&gt;14&lt;/sup&gt;C concentrations of recent landslide deposits and catchments from the Fiordland and the Southern Alps of New Zealand to: (a) estimate landslide frequencies over 10&lt;sup&gt;3&lt;/sup&gt;-10&lt;sup&gt;4&lt;/sup&gt; yr timescales, which we compare against landslide inventories mapped from air photos (&lt;10&lt;sup&gt;2&lt;/sup&gt; yrs) to estimate changes in landslide activity, (b) quantify catchment-averaged erosion rates, and landslide&amp;#8217;s contribution to those erosional fluxes, and (c) test whether paired &lt;sup&gt;14&lt;/sup&gt;C-&lt;sup&gt;10&lt;/sup&gt;Be measurements can be used to trace erosional depth-provenance and identify transient erosion rate changes. We show that &lt;sup&gt;10&lt;/sup&gt;Be concentrations on landslide deposits can be used to estimate landslide recurrence intervals and frequency over 10&lt;sup&gt;3&lt;/sup&gt; yr timescales, and that &lt;sup&gt;14&lt;/sup&gt;C/&lt;sup&gt;10&lt;/sup&gt;Be ratios reflect the depth-provenance of sediment, and possibly transient changes in erosion rates. The comparison of our &lt;sup&gt;10&lt;/sup&gt;Be-based long-term landslide frequencies with short-term published inventories suggests that landslide frequencies have increased towards the present by up to an order of magnitude. We compare sediment fluxes inferred from these long- and short-term landslide inventories with sediment flux estimates derived from &lt;sup&gt;10&lt;/sup&gt;Be catchment-averaged erosion rates, which allows us to examine fluctuations in erosion rate estimates from 10&lt;sup&gt;1&lt;/sup&gt; to 10&lt;sup&gt;3&lt;/sup&gt; yrs timescales.&amp;#160;&lt;/p&gt;

The long-term denudation rate of granitic regolith in Qinhuangdao, North China determined from the in situ depth profile of the cosmogenic nuclides 26Al and 10Be

2014 ◽  
Vol 59 (34) ◽  
pp. 4823-4828 ◽  
Author(s):  
Lifeng Cui ◽  
Congqiang Liu ◽  
Sheng Xu ◽  
Zhiqi Zhao ◽  
Chenglong Tu ◽  
...  
Keyword(s):  
Depth Profile ◽  
North China ◽  
Cosmogenic Nuclides ◽  
Denudation Rate

scholarly journals Tracing erosion rates in loess landscape of the Trzebnica Hills (Poland) over time using fallout and cosmogenic nuclides

2021 ◽  
Author(s):  
Aleksandra Loba ◽  
Jarosław Waroszewski ◽  
Dmitry Tikhomirov ◽  
Fancesca Calitri ◽  
Marcus Christl ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Temporal Trends ◽  
Short Term ◽  
Undisturbed Soil ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Fallout Radionuclides ◽  
Soil Erosion Rates

Abstract Purpose Loess landscapes are highly susceptible to soil erosion, which affects soil stability and productivity. Erosion is non-linear in time and space and determines whether soils form or degrade. While the spatial variability of erosion is often assessed by either modelling or on-site measurements, temporal trends over decades to millennia are very often lacking. In this study, we determined long- and short-term erosion rates to trace the dynamics of loess deposits in south-western Poland. Materials and methods We quantified long-term (millennial) erosion rates using cosmogenic (in situ 10Be) and short-term (decadal) rates with fallout radionuclides (239+240Pu). Erosion processes were studied in two slope-soil transects (12 soil pits) with variable erosion features. As a reference site, an undisturbed soil profile under natural forest was sampled. Results and discussion The long-term erosion rates ranged between 0.44 and 0.85 t ha−1 year−1, whereas the short-term erosion rates varied from 1.2 to 10.9 t ha−1 year−1 and seem to be reliable. The short-term erosion rates are up to 10 times higher than the long-term rates. The soil erosion rates are quite consistent with the terrain relief, with erosion increasing in the steeper slope sections and decreasing in the lower parts of the slope, while still maintaining high values. Conclusions Soil erosion rates have increased during the last few decades owing to agriculture intensification and probably climate change. The measured values lie far above tolerable erosion rates, and the soils were found to be strongly imbalanced and exhibit a drastic shallowing of the productive soils horizons.

scholarly journals Histories and Mechanisms of Change in the Development of Shore Platforms at Kaikoura and Rodney New Zealand: Application of Cosmogenic Nuclides and Numerical Modelling on Exposed Coastal Surfaces

2021 ◽  
Author(s):  
◽  
Aidan Duart McLean
Keyword(s):  
New Zealand ◽  
Numerical Modelling ◽  
Sea Level ◽  
Late Holocene ◽  
Cosmogenic Nuclides ◽  
Erosion Rates ◽  
Cliff Erosion ◽  
Exposure Ages ◽  
Shore Platforms

<p>Global sea level rise is contributing to the acceleration of cliff erosion rates in New Zealand, where it surpasses rates of uplift. A significant challenge facing scientists and managers is that we have no method for reliably extracting past rates of coastal erosion along harder rock cliffs over the time-scales that significant sea level change occurs (100s-1000s of years). This gap in knowledge is limiting efforts to model and understand the relationship between sea level rise and cliff erosion rates and what form of that relationship takes. Cosmogenic Beryllium-10 analysis has been applied on two low angle shore platforms in New Zealand to produce chronologies of sea cliff retreat during the late-Holocene. Surface exposure ages were attained on a tectonically active platform at Kaikoura, Canterbury and a tectonically quiescent platform at Cape Rodney, Auckland. This is the first application of cosmogenic nuclides to a shore platform study in New Zealand and adds two new data-sets to the very small group of global shore platform chronologies. Exposure ages show New Zealand platforms have developed in the late-Holocene. Long-term platform surface erosion rates at Kaikoura (0.4mm a-1), potentially due to uplift driven positive feedback such as altered sea level position, driving up weathering rates on the tidally inundated platform. Nuclide concentrations at Okakari Point, Rodney, reveal a significant role of recent sea level fall after ~4000yrs BP, driving surface denudation (0.1mm a-1). The long-term cliff back-wearing rate at Okakari point was found to be 24.66mm a-1. Patterns in cosmogenic nuclide concentrations in New Zealand’s shallow platforms differ from global examples recorded on steeper platforms. Exploratory numerical modelling was applied with the coupled Rocky Profile CRN model (RPM_CRN) to identify process relationships between key drivers within platform coastal systems and scenarios of sea level change and active tectonics. This combined geochemical and numerical modelling study has shown that shore platforms in New Zealand have complex histories, with different potential driving forces at Kaikoura and Okakari. This highlights the local variability in platform development and cliff retreat, suggesting that estimates of future shoreline erosion will need to take local contingencies into account.</p>

scholarly journals Histories and Mechanisms of Change in the Development of Shore Platforms at Kaikoura and Rodney New Zealand: Application of Cosmogenic Nuclides and Numerical Modelling on Exposed Coastal Surfaces

2021 ◽  
Author(s):  
◽  
Aidan Duart McLean
Keyword(s):  
New Zealand ◽  
Numerical Modelling ◽  
Sea Level ◽  
Late Holocene ◽  
Cosmogenic Nuclides ◽  
Erosion Rates ◽  
Cliff Erosion ◽  
Exposure Ages ◽  
Shore Platforms

<p>Global sea level rise is contributing to the acceleration of cliff erosion rates in New Zealand, where it surpasses rates of uplift. A significant challenge facing scientists and managers is that we have no method for reliably extracting past rates of coastal erosion along harder rock cliffs over the time-scales that significant sea level change occurs (100s-1000s of years). This gap in knowledge is limiting efforts to model and understand the relationship between sea level rise and cliff erosion rates and what form of that relationship takes. Cosmogenic Beryllium-10 analysis has been applied on two low angle shore platforms in New Zealand to produce chronologies of sea cliff retreat during the late-Holocene. Surface exposure ages were attained on a tectonically active platform at Kaikoura, Canterbury and a tectonically quiescent platform at Cape Rodney, Auckland. This is the first application of cosmogenic nuclides to a shore platform study in New Zealand and adds two new data-sets to the very small group of global shore platform chronologies. Exposure ages show New Zealand platforms have developed in the late-Holocene. Long-term platform surface erosion rates at Kaikoura (0.4mm a-1), potentially due to uplift driven positive feedback such as altered sea level position, driving up weathering rates on the tidally inundated platform. Nuclide concentrations at Okakari Point, Rodney, reveal a significant role of recent sea level fall after ~4000yrs BP, driving surface denudation (0.1mm a-1). The long-term cliff back-wearing rate at Okakari point was found to be 24.66mm a-1. Patterns in cosmogenic nuclide concentrations in New Zealand’s shallow platforms differ from global examples recorded on steeper platforms. Exploratory numerical modelling was applied with the coupled Rocky Profile CRN model (RPM_CRN) to identify process relationships between key drivers within platform coastal systems and scenarios of sea level change and active tectonics. This combined geochemical and numerical modelling study has shown that shore platforms in New Zealand have complex histories, with different potential driving forces at Kaikoura and Okakari. This highlights the local variability in platform development and cliff retreat, suggesting that estimates of future shoreline erosion will need to take local contingencies into account.</p>

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