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Meteoric beryllium‐10 (10Bem, t1/2= 1.4 Myr) is a cosmogenic radionuclide that remains largely underutilized for deriving hillslope‐scale estimates of erosion on uplands under conditions of land use change. We applied two different models for estimating erosion rates from observed 10Bemconcentrations (a one‐dimensional model predicting vertical profiles of 10Bemwithin hillslope soils [loss only, diffusion only, LODO] and a two‐dimensional model predicting the concurrent evolution of hillslope topography and 10Bemdistributions via bioturbation, chemical mobility, and surface erosion [Be2D]). Both models were used to derive pre‐European and post‐European settlement erosion rates (Enatand Epost, respectively) across paired cultivated and uncultivated hillslopes in west‐central Minnesota, USA. Epostestimates from 10Bemwere compared to Epostestimates derived from 137Cs inventories and the process‐based Water and Tillage Erosion Model (WaTEM). The results from these models suggest that erosion rates from upper positions on the cultivated hillslope have increased from an average of 0.047 mm/year under natural conditions to Epostvalues of 3.09 mm/year. The Be2D and LODO models, on average, produced Epostestimates that were similar in magnitude to WaTEM and 137Cs conversion models. This numerical convergence does not imply absolute 10Bemmodel accuracy, particularly when considering the uncertainties inherent in each approach, but it does suggest that the orders of magnitude increase in estimated erosion rates from Enatto Epostis robust. Additionally, the pattern of Epostestimates produced using 10Bemconversion models is supported by the distribution of soil inorganic carbon at the study site. Our results demonstrate that 10Bemcan provide reasonable estimates of both predisturbance and postdisturbance erosion rates in landscapes that have undergone extensive human modification. Agricultural practices have substantially changed soil erosion rates in the Midwestern United States. Although much work has been devoted to understanding the changes in soil erosion rates with land cover change, the ability to quantify those changes at discrete locations on the landscape over long periods of time has been limited. We use a set of tracers and models to estimate presettlement and postsettlement erosion rates on a hillslope in west‐central Minnesota, USA, and show that soil erosion has increased by approximately 1 to 2 orders of magnitude over a period of approximately 110 years. This has implications for how we view our current agricultural landscapes and how we think about soil sustainability in the future. Meteoric beryllium‐10 is used to generate point‐based estimates of long‐term erosion on paired hillslopesThese estimates suggest that erosion rates have increased by 2 orders of magnitude under agricultural managementModel choice influences erosion rate magnitude, but average rates are similar to estimates from process‐based models and cesium‐137

Along glaciated margins, ratios of meteoric cosmogenic beryllium‐10, 10Be, normalized to its stable isotope, 9Be, reflect an environmental signal, driven ultimately by climatic change. We explore the application of this isotopic pair as a proxy for East Antarctic Ice Sheet dynamics. We analyze 10Be/9Be in middle Pliocene glaciomarine sediments offshore the Wilkes Land Region (Integrated Ocean Drilling Program (IODP) Site U1361A) and examine our new record alongside existing biochemical/geochemical records (Ba/Al, opal %wt, εNd, and 87Sr/86Sr). 10Be/9Be ratios reach local maxima during pulsed, mild warming events and are strongly correlated with existing records that indicate concurrent ice sheet retraction and increased bioproductivity. We suggest climate change as the primary driver of the 10Be/9Be record near glaciated margins, whereby increased warming drives ice sheet retraction, discharging freshwaters and diluting the open ocean 10Be/9Be signal recorded in authigenic minerals. If the entire Antarctic Ice Sheet collapsed, it would raise global sea level by about 60 m (200 feet). How sensitive is the ice sheet to warming temperatures? Should we expect extreme sea level rise by the middle to late century, when global average temperatures could warm by about 2 °C (3.6 °F) or more? To answer these questions, earth scientists design numerical models to simulate ice sheet behavior and improve those models using physical evidence. High‐quality physical evidence is found in the marine sedimentary record deposited in the past under analogous warm conditions, such as during the Pliocene period (2.6–5.3 million years ago). The elemental and isotopic composition of these marine sediments gives clues as to how the ice sheet has reacted to warming temperatures. One such isotope is beryllium‐10 (10Be), which, in specific environments, fluctuates in tandem with glacial‐interglacial transitions. As additional marine sediment records identify specific mechanisms of ice mass loss at work, we begin to strengthen predictions of sea level rise from numerical simulations. 10Be/9Be in Pliocene‐age glaciomarine sediments offshore the Wilkes Subglacial Basin (WSB) reflect oscillations in the East Antarctic Ice Sheet (EAIS)Freshwater discharge via basal ice melt can account for the observed 10Be inventory entering Adélie Land Bottom Water (ALBW)Variation in the 10Be/9Be ratio is used to estimate freshwater discharge and deep water dilution

The lateral migration of a river meander is driven by erosion on the outer bank and deposition on the inner bank, both of which are affected by shear stress (and therefore channel slope) through complex morphodynamic feedbacks. To test the sensitivity of lateral migration to channel slope, we quantify slope change induced by glacial isostatic adjustment along the Red River (North Dakota, USA and Manitoba, Canada) and two of its tributaries over the past 8.5 ka. We demonstrate a statistically significant, positive relationship between normalized cutoff count, which we interpret as a proxy for channel lateral migration rate, and slope change. We interpret this relationship as the signature of slope change modulating the magnitude of shear stress on riverbanks, suggesting that slope changes that occur over thousands of years are recorded in river floodplain morphology. Rivers move through the landscape by eroding river bank material on their outer bank and depositing sediment on their inner bank, a process that forms meander bends. Understanding what factors drive river meandering is important for interpreting how rivers interact with landscapes. One factor that could impact river meandering is river slope. To understand the impact of slope on river meandering we quantify how slope has changed along the Red River (North Dakota, USA and Manitoba, Canada) over the past 8.5 Kyr. Over this time, vertical land movement substantially reduced the slope of the river, through the ongoing solid Earth response to the retreat of massive North American ice sheets in a process known as glacial isostatic adjustment (GIA). We find that change in slope, induced by GIA, positively correlates with river migration rate along the Red River, suggesting that slope plays an important role in determining the pace of river meandering. Glacial isostatic adjustment (GIA) is the primary control on slope change for the Red River (ND, USA and MB, Canada) since it began to flow 8.5 kaSlope change caused by GIA significantly correlates with river cutoff frequency, a proxy for lateral migration rateWe infer that slope change modulates the magnitude of shear stress on the riverbank, driving changes in lateral migration rate Glacial isostatic adjustment (GIA) is the primary control on slope change for the Red River (ND, USA and MB, Canada) since it began to flow 8.5 ka Slope change caused by GIA significantly correlates with river cutoff frequency, a proxy for lateral migration rate We infer that slope change modulates the magnitude of shear stress on the riverbank, driving changes in lateral migration rate

Environmental contextBeryllium is a toxic environmental contaminant but has many industrial and scientific applications. Our work explores the effects of soil composition on beryllium retention, focussing on organic matter, mineralogy and pH and concludes that phosphorus and sulfur oxides in addition to soil acidity are strong controls on beryllium mobility. These results aid in future predictions regarding the fate of beryllium in the environment. AbstractUnderstanding the chemical controls on beryllium sorption is fundamental when assessing its mobility as a pollutant and interpreting its concentration as a geochemical tracer of erosion, weathering and landscape surface stability. In order to evaluate the interactions of beryllium with soil- and aquatic-related materials, we selected model organic compounds and minerals to perform sorption experiments. The retention of beryllium by each of these compounds and minerals was evaluated over a pH range of 3–6 and at various equilibration times to determine which conditions allowed the greatest retention of beryllium. We conclude that most beryllium sorption occurred within 24h for both organic and mineral materials. However, equilibration required longer periods of time and was dependent on the solution pH and sorbent material. The pH exhibited a strong control on beryllium sorption with distribution coefficient (Kd) values increasing non-linearly with increasing pH. A system with a pH of 6 is likely to retain 79–2270% more beryllium than the same system at a pH of 4. Phosphonate retained the greatest amount of beryllium, with Kd values 2–30× greater than all other materials tested at a pH of 6. Therefore, soils containing larger amounts of phosphorus-bearing minerals could result in greater retention of beryllium relative to phosphorus-limited soils. Overall, soil composition, with an emphasis on phosphorus oxide content and pH, is an important property to consider when evaluating the capacity of a system to retain beryllium.

Measuring rates of valley head migration and determining the timing of canyon‐opening are insightful for the evolution of planetary surfaces. Spatial gradients of in situ‐produced cosmogenic nuclide concentrations along horizontal transects provide a framework for assessing the migration of valley networks and similar topographic features. We developed a new derivation for valley head retreat rates from the concentrations of in situ‐produced cosmogenic radionuclides in valley walls. The retreat rate is inversely proportional to the magnitude of the spatial concentration gradient and proportional to local nuclide production rates. By solving for a spatial gradient in concentration along a valley parallel transect, we created an expression for the explicit determination of valley head retreat, which we refer to herein as unzipping. We applied this expression to a seepage‐derived drainage network developing along the Apalachicola River, Florida, USA. Sample concentrations along a valley margin transect varied systematically from 2.9 × 105to 3.5 × 105atoms/g resulting in a gradient of 160 atoms/g/m, and from this value a valley head retreat rate of 0.025 m/y was found. The discrepancy between overall network age and current rates of valley head migration suggests intermittent network growth which is consistent with glacial‐interglacial precipitation variations during the Pleistocene. This method can be applied to a wide range of Earth‐surface environments. For the 10Be system, this method should be sensitive to unzipping rates bounded between 10−6and 100m/y. The pace at which landforms develop is an important control on many biological, chemical, and physical processes operating at Earth's surface. Rates of landscape change are often quantified by measuring the accumulation of cosmogenic radionuclides in near‐surface Earth materials, as an indicator of the erosion rate and age of landforms. In this study, we advance a method for querying the rate of horizontal topographic changes, such as valley growth or ice margin retreat, by sampling material in a horizontal transect and observing patterns in the nuclide concentrations in a spatial gradient. We present the results of numerical modeling that describe the limits of this approach due to the rate and consistency of ongoing landscape evolution processes. We present the first empirical data on the growth rate of a well‐studied seepage channel network in Florida, which suggests that the time‐averaged channel advance rate is 0.025 m/y. Furthermore, our measurements indicate that the age of the incising plateau surface is between 2 and 2.5 My and that the regional uplift rate is between 27 and 38 m/My. Propagation rates of morphologic features determined by nuclide concentration gradients along a horizontal transectUplift rate of the Florida panhandle estimated between 0.027 and 0.038 mm/y from a nuclide depth profileChanges in climate over the Quaternary likely drove variable growth rates of seepage valleys along the Apalachicola River Propagation rates of morphologic features determined by nuclide concentration gradients along a horizontal transect Uplift rate of the Florida panhandle estimated between 0.027 and 0.038 mm/y from a nuclide depth profile Changes in climate over the Quaternary likely drove variable growth rates of seepage valleys along the Apalachicola River

•Mobility of asbestos fibers increased in the presence of dissolved organics.•Quality of dissolved organics influenced the extend of fiber transport.•Transport potential varied: fulvic acid > humic acid > natural organic matter.•Dissolved organic altered surface charge and stability of chrysotile fibers.