Earth Surface Processes and Landforms最新文献

{"title":"Development of the critical zone environment in the highly dynamic landscape of the Forni Glacier forefield: Winds, tree vegetation, pedogenesis and surface waters after glacier retreat","authors":"Giovanni Leonelli, Anna Masseroli, Luca Trombino, Alessio Golzio, Adalberto Bonetti, Valter Maggi, Manuela Pelfini","doi":"10.1002/esp.5983","DOIUrl":"https://doi.org/10.1002/esp.5983","url":null,"abstract":"The expansion of glacier‐free forelands after glacier retreat is emerging as a typical climate change‐dependent feature that is widely studied for assessing biogeomorphic feedbacks and analysing the vertical processes and changes occurring in the critical zone (CZ). However, the horizontal processes occurring in the CZ environment are still poorly understood. Here, we comprehensively analyse the development of the CZ environment over time in the Forni Glacier forefield, Italian Alps, since the end of the Little Ice Age (LIA) by considering different sectors (air, forest, water and soil) in two portions of the glacier forefield: the lower portion, which occurs below the glacier‐forefield treeline (GFT), where a fully functioning CZ environment has developed, and the upper portion, which occurs above the GFT, in the proglacial area (PA), where only an incipient CZ exists. The early stages of CZ development in the PA are highly influenced by katabatic winds, which impact the colonisation patterns of saplings and young trees, and characterised by high‐energy geomorphic processes that cause sediment reworking and initial stages of soil development. Below the GFT, the minimum tree ecesis interval after glacier retreat reaches a median value of 38 years (<jats:italic>n</jats:italic> = 8), and the fully developed CZ environment (with trees reaching at least 2 m in height after 20 years) formed after ~60 years following glacier retreat and is characterised by forest cover, soils organised in a chronosequence and contrasting isotopic signatures of surface and running waters. The correlation with the isotopic signatures of tree rings allowed us to estimate a groundwater flow period of approximately 2 months from the slopes into the CZ of the valley floor. By analysing the horizontal processes driving the geomorphic and biotic evolution patterns of a glacier forefield, this work introduces a novel approach for assessing the development of the CZ environment over time.","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"669 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imbrication fabric as a diagnostic feature for the genetic classification of gravels deposited by fluid-gravity versus sediment-gravity subaerial flows","authors":"Andrea Brenna,&nbsp;Ivan Martini,&nbsp;Luca Menapace,&nbsp;Nicola Surian,&nbsp;Dario Ventra,&nbsp;Massimiliano Ghinassi","doi":"10.1002/esp.5986","DOIUrl":"10.1002/esp.5986","url":null,"abstract":"<p>Gravel transport in subaerial environments occurs through different flows that are conveniently classified as debris flows, debris floods and water flows based on their distinct morpho-sedimentary dynamics and different implications for geomorphic hazard. Because distinctive features allowing gravelly sedimentary bodies to be ascribed to related genetic process are still a matter of discussion, this study aims to establish whether imbrication fabric represents a sedimentological fingerprint potentially applicable towards a more robust genetic classification of gravels. We analysed the fabric of 1007 imbricated clasts from modern and ancient deposits. Our results highlight statistically significant differences between imbrication fabrics in gravels deposited by different flows. Particles imbricated by water flows are typified by low imbrication angles (median of 35°) and elongated clasts oriented perpendicular to the flow. In contrast, debris-flow gravels exhibit high imbrication angles (median of 65°) and elongated clasts oriented parallel to the flow. Debris-flood deposits display elongated clasts both parallel and transverse to the main flow and intermediate values of imbrication angle (median of 47°). We propose that imbrication angles result from the combination of stability-driven selection—a process acting under tractional transport and promoting the remobilization of high-angle imbrication fabrics—and shear-stress-driven overriding—a mechanism leading to the formation of the higher imbrication angles—with the first dominating in water flows and the latter being effective in mass transport processes. The progressive change in imbrication fabrics from fluid-gravity to sediment-gravity flow deposits offers easily quantifiable sedimentological evidence to help in distinguishing genetic processes that contribute to the accumulation of gravels in alluvial and colluvial settings. Analysis of imbrication fabric can add valuable information, particularly as regards the classification of (1) coarse deposits in stratigraphic records and (2) modern debris flood deposits.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4088-4098"},"PeriodicalIF":2.8,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.5986","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mio-Pliocene paleo-course of Indus River in Upper Sutlej-Zhada basin: Implication of tectonic uplift on river piracy and drainage reorganization in SW Tibet and NW Himalaya","authors":"Abhishek Kashyap,&nbsp;Anand Kumar Pandey,&nbsp;Mukunda Dev Behera","doi":"10.1002/esp.5977","DOIUrl":"10.1002/esp.5977","url":null,"abstract":"<p>We analysed the elevated low-relief relict landscapes in the transient Upper Satluj-Zhada basin and the adjoining region in the tectonically active north-western (NW) Himalaya–south-western (SW) Tibetan orogen to understand the evolution of the regional landscape and drainage system under the influence of the Karakoram Fault-Leo-Pargil Horst system. This elevated low relief landscape represents the Mio-Pliocene establishment of a new river network, which testimonies the present Sutlej River, which has been experiencing a transient surface uplift-incision regime since (~4–1 Ma) with a local base level at the confluence of the Sutlej and Spiti River. The Miocene exhumation of the Ayilari Range and Leo-Pargil Horst across the Karakoram fault (KF) system led to headward erosion, which abandoned the Paleo-Sutlej-Indus drainage system, which in turn caused drainage reversal along Qusum detachment (QD) and produced southward migration of the Paleo-Sutlej River towards the mountain front. Our results indicate that the Upper Indus River has significantly lower χ-ranges at higher elevations as compared with the adjacent Upper Sutlej River at lower elevations, which corresponds with a river piracy model that incorporates area gain-loss feedback. The Upper Sutlej River in the Zhada basin is characterized by a comparable series of coplanar slope-break knickpoints at ~4000–4500 m elevation, and their adjoining divides are in a state of disequilibrium as a consequence of the very high rapid incision across the Leo Pargil Horst, which drives the regional gradation process. The headward-eroding Upper Indus River captured the proto-Sutlej due to a base-level change of &gt;~1500 m, which significantly impacted the regional growth pattern and tectonics. The Mio-Pliocene sedimentation pattern of the Upper Sutlej-Zhada basin in the SW Tibet–NW Himalaya reflects this regional drainage capture, tectonic uplift and paleo-drainage reorganization. The present finding has wider implications for the Mio-Pliocene reorganization of drainage systems and the possible linkage of the Upper Indus River with the Paleo-Sutlej over the Zhada basin.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4428-4443"},"PeriodicalIF":2.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.5977","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to ‘Mangrove forest drag and bed stabilisation effects on intertidal flat morphology’","authors":"","doi":"10.1002/esp.5971","DOIUrl":"10.1002/esp.5971","url":null,"abstract":"<p>\u0000 <span>Gijsman, R.</span>, <span>Horstman, E.M.</span>, <span>Swales, A.</span>, <span>MacDonald, I.T.</span>, <span>Bouma, T.J.</span>, <span>Wal, D.</span>, <span>Wijnberg, K.M.</span> (<span>2024</span>) <span>Mangrove forest drag and bed stabilisation effects on intertidal flat morphology</span>. <i>Earth Surface Processes and Landforms</i>, <span>49</span>(<span>3</span>), <span>1117</span>–<span>1134</span>, https://doi.org/10.1002/esp.5758</p><p>In the Data Availability Statement of the ‘Open Research’ section, the authors missed the opportunity to mention that the hydrodynamic data that were specifically used for the calibration of the drag coefficients were obtained by the University of Waikato. The calibration of the drag coefficients is presented in Section S2 of the ‘Supporting Information’. For that reason, the authors would like to add the following sentence to the Data Availability Statement: ‘The hydrodynamic data that are used for the calibration of the drag coefficients are available from the University of Waikato upon reasonable request’.</p><p>Accordingly, in the ‘Acknowledgements’, the authors would like to adjust the sentence ‘Pressure, profile and vegetation data was partly obtained in prior field campaigns funded by the Royal Society of New Zealand's Marsden Fund (grant 14-UOW-011)’ to ‘Pressure, profile and vegetation data were partly obtained in prior field campaigns by EMH, Karin Bryan and Julia Mullarney (University of Waikato), funded by the Royal Society of New Zealand's Marsden Fund (grant 14-UOW-011)’.</p><p>The authors apologize for this inaccuracy.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 12","pages":"4074"},"PeriodicalIF":2.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.5971","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting soil loss in small watersheds under different emission scenarios from CMIP6 using random forests","authors":"Yulan Chen,&nbsp;Nan Wang,&nbsp;Juying Jiao,&nbsp;Jianjun Li,&nbsp;Leichao Bai,&nbsp;Yue Liang,&nbsp;Yanhong Wei,&nbsp;Ziqi Zhang,&nbsp;Qian Xu,&nbsp;Zhixin Zhang,&nbsp;Jiaxi Wang","doi":"10.1002/esp.5980","DOIUrl":"10.1002/esp.5980","url":null,"abstract":"<p>Soil loss is a common land degradation process worldwide, which is impacted by land use and climate change. In this study, random forests (RF) were first used to establish a soil loss model at the scale of a small watershed in the hilly-gully region of the Loess Plateau based on the field observation data. Subsequently, the model was used to predict soil loss in the Chabagou watershed under the historical (1990–2020) and future emission scenarios, namely SSP1–2.6 (low-emission), SSP2–4.5 (medium-emission) and SSP5–8.5 (high-emission) (2030–2,100) from the Coupled Model Intercomparison Project Phases 6 (CMIP6). In the RF model, the coefficient of determination (R²) and Nash-Sutcliffe coefficient of efficiency (NS) were both greater than 0.86, and the RMSE-observations standard deviation ratio (RSR) was less than 0.36. Additionally, the RF-based model had higher simulation accuracy and robustness than those of the previous soil loss models, indicating its potential for wider applications in simulating soil loss. Compared with soil loss between 1990 and 1999, climate change led to a 35.36% increase in soil loss, while land use change resulted in an 11.13% reduction from 2000 to 2020 in the Chabagou watershed. This reveals that the current land use management could not effectively counterbalance the soil loss caused by rainstorms. Furthermore, compared with the historical period (1990–2020), under SSP1–2.6, SSP2–4.5 and SSP5–8.5 (2030–2,100), the soil loss rates without land use change would be increased by 6.01%, 19.11% and 35.35%, while the soil loss rates with land use change would be changed by −5.88%, +4.41% and +19.12%, respectively. These results help to provide a scientific basis for enhancing the capacity to respond to climate change and mitigation of soil and water loss on the Loess Plateau.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4469-4484"},"PeriodicalIF":2.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An adaptive low-rank group sparse model based on edge-preserving for eliminating mixed noise in SRTM","authors":"Xiao Fan,&nbsp;Hongming Zhang,&nbsp;Qinke Yang,&nbsp;Baoyuan Liu,&nbsp;Chenyu Ge,&nbsp;Zhuang Yan,&nbsp;Yuwei Sun,&nbsp;Jincheng Ni,&nbsp;Linlin Yuan,&nbsp;Xiaoxing Huang","doi":"10.1002/esp.5976","DOIUrl":"10.1002/esp.5976","url":null,"abstract":"<p>The Shuttle Radar Topography Mission (SRTM) is a digital representation of the terrain surface morphology that contains rich terrain information and is widely used in environmental analyses. However, SRTM is adversely affected by mixed noise, which typically include random and stripe noise. Mixed noise results in the significant loss of topographic information, which reduce the validity of related research. To eliminate mixed noise in SRTM data, we propose an adaptive low-rank group sparse model based on edge preservation (ALGS_EP) to remove mixed noise from datasets. The method relies on a low-rank group sparse model that considers the gradient features of the terrain. It calculates a terrain factor to adapt the noise elimination model to terrain changes. Additionally, it integrates with the edge structure of elevation data and applies a double-gradient constraint to preserve the structural details of the elevation data. The proposed model, built upon the alternating direction multiplier method framework, enhances the traditional weighted kernel paradigm minimization algorithm by introducing variable weights that adjust according to the gradient of elevation data during iterations. Additionally, it incorporates the correlation between strip noise and residual data blocks when computing the iteration count, ensuring an iterative solution approach that converges to the optimal solution. We used ALGS_EP to process global SRTM 1 data and published a higher-quality and higher-precision elevation dataset. The elevation data noise before and after noise elimination were statistically analyzed. Simulated and empirical results show that the model is highly robust and more effective than existing methods in both visual and quantitative evaluations. The noise elimination rate was 97.6%, compared to the original data. Therefore, this research was valuable for applications that use digital elevation model as an important data layer.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4404-4427"},"PeriodicalIF":2.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phreatic overgrowths on speleothems (POS) from the Mallorca caves: Morphology, mineralogy, and crystal fabric classification","authors":"Ana Entrena,&nbsp;Luis F. Auqué,&nbsp;María J. Gimeno,&nbsp;Joan J. Fornós","doi":"10.1002/esp.5967","DOIUrl":"10.1002/esp.5967","url":null,"abstract":"<p>Phreatic overgrowths on speleothems (POS) are unique precipitates that are found in a small number of coastal caves around the world, like those in the Mallorca Island. Their growth is directly related to the water level of the brackish lakes connected to the sea characteristic of these caves and, therefore, they can be very reliable indicators of past sea levels. The study presented here characterizes and classifies an important number of POS samples collected in the coastal caves of Mallorca. The characterization includes not only the observations made on 117 handheld samples and on 102 thin sections from POS, but also the study of their mineralogy and their location in the caves. This study has provided the basis for a systematization of all these characteristics, some of which are reported here for the first time in POS samples. The results indicate that (1) most of the POS precipitate on stalactites, (2) calcite POS show branched internal and external texture and their most common crystal fabric is mosaic calcite and (3) aragonite POS show globular external texture and fan-shaped internal texture, and their principal crystal fabric is needle-like. All the aragonitic samples have been found above or at the same heights as the current sea level, which indicates that they have probably formed during warmer climates. The calcite POS have been found at heights above and below the present sea level and are interpreted as to have formed during cold and rainy periods. The systematization proposed in this paper could be applied and checked in other POS worldwide. Additionally, the combination of these results with the information obtained from studies on the present precipitation of these phreatic speleothems in some Mallorca caves has provided an insight on their formation conditions which will enlarge the utility of these speleothems as palaeoenvironmental indicators.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4289-4309"},"PeriodicalIF":2.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.5967","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permafrost thaw and thermokarst in the source region of the Yangtze river in the central Tibetan plateau revealed by radar and optical remote sensing","authors":"Lingxiao Wang,&nbsp;Chenqi Huang,&nbsp;Lin Zhao,&nbsp;Huayun Zhou,&nbsp;Shibo Liu,&nbsp;Yunqi Tang,&nbsp;Zhibin Li,&nbsp;Yao Xiao,&nbsp;Defu Zou,&nbsp;Guangyue Liu,&nbsp;Erji Du,&nbsp;Guojie Hu,&nbsp;Chong Wang","doi":"10.1002/esp.5969","DOIUrl":"10.1002/esp.5969","url":null,"abstract":"<p>The landscape and landforms in permafrost regions are transforming due to climate change and permafrost thaw. This study uses optical and radar remote sensing, alongside spatial analysis, to examine thermokarst features and their driving factors in the source region of the Yangtze River (SRYR) on the central Tibetan Plateau. We analyse the distribution, interaction, and key environmental factors influencing thermokarst ponds and ground surface deformation, which are the two widespread and noticeable thermokarst features. Since the 1960s, the number of small water bodies has doubled from approximately ~2 × 10⁴ to ~4 × 10⁴ by the 2020s, with the median size of these water bodies decreasing from 2.3 × 10⁴ m² to 1.4 × 10⁴ m². The permafrost terrain has an average subsidence rate of 6.8 mm/a. About 50.9% of the SRYR exhibits evident thermokarst features. Surficial geological factors, especially geomorphology and slope, are primary factors in shaping the spatial distributions of thermokarst features. Both seasonal deformation and long-term subsidence rates are more pronounced in areas with thermokarst ponds. However, once pond coverage exceeds around 5%, the amplifying effect on long-term subsidence rates and seasonal deformation diminishes. The investigation further reveals that the relationship between seasonal deformation and long-term subsidence is not strictly linear and that the combined increase in seasonal deformation and long-term subsidence applies only to areas with seasonal deformation below approximately 20 mm. Beyond this threshold, the long-term subsidence rate is no longer exacerbated by increased seasonal deformation.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4324-4339"},"PeriodicalIF":2.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Site-scale drivers of post-fire vegetation regrowth in gullies: A case study in Mediterranean Europe","authors":"Bruno Martins,&nbsp;Catarina Pinheiro,&nbsp;Adélia Nunes,&nbsp;António Bento-Gonçalves,&nbsp;Manuela Laranjeira","doi":"10.1002/esp.5974","DOIUrl":"10.1002/esp.5974","url":null,"abstract":"<p>Mediterranean forests are very degraded, mainly due to the intensification of wildfires in recent decades, which, boosted by human activity, have contributed to the acceleration of erosion processes and soil degradation. Under certain conditions, this also contributes to the formation of gullies. The aim of this study is to identify and characterise gullies considering their morphological and topographical aspects and determine the factors that control vegetation regrowth in gullies in a Mediterranean environment after a wildfire. The gullies were identified based on the 2018 orthophotograph, after the large wildfire of October 2017 that affected the entire study area. To analyse the vegetation regrowth, we used the normalised difference vegetation index (NDVI) derived from seven Landsat 8 OLI/TIRS images (2017–2022). The Spearman's rho correlation coefficient was selected to estimate the correlation between gully characteristics and vegetation regrowth. Before running the model, a multicollinearity test was conducted (<i>VIF</i> ≤ 10 and tolerance ≥ 0.1). Stepwise multiple regression was conducted in order to identify the independent variable that has a strong relationship with vegetation regrowth. A marginal effects plot was drawn up. The 38 gullies identified are in forest areas, mainly composed of pine (<i>Pinus pinaster</i>) trees (17 gullies) or a combination of pine trees and broadleaf (<i>Eucalyptus globulus</i>) trees (eight gullies). In all, invasive species are present in 11 gullies, alone (one gully), together with pine trees (four gullies) or with other species (six). The other gully has broadleaf trees. The vegetation in the gully channel recovered well in the year after the wildfire. In the following years there was growth at a slower rate until it reached similar values of NDVI in 2022, 5 years after the wildfire. Stepwise multiple regression (SMR) produced a solution with three models. The three derived dimensions covered 66.8% of the variance, considering the mean width, altitude and flow accumulation. The results can help to devise more effective management strategies for areas where the recurrence and intensity of wildfires have contributed very effectively to soil loss and degradation from gully erosion, with a view to a more resilient and sustainable territory.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4371-4387"},"PeriodicalIF":2.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the effects of carborundum rock surface smoothing for Schmidt hammer R-value metrics measured on glacial erratics in the North American Great Lakes region","authors":"Brianna Shepherd,&nbsp;Eric W. Portenga,&nbsp;Alexys J. Peplinski","doi":"10.1002/esp.5973","DOIUrl":"10.1002/esp.5973","url":null,"abstract":"<p>Schmidt hammer R-values, which reflect the degree of rock surface weathering, can be paired with independent rock surface exposure ages to produce Schmidt hammer exposure-age dating (SHD) calibration curves that are used to provide rapid estimations of exposure ages for undated rock surfaces. In this Letter, we lay the groundwork for later establishing a SHD calibration curve based on glacial erratics deposited by the Laurentide Ice Sheet in the North American Great Lakes region. First, we establish a reference R-value for a calibration boulder, which may be used to facilitate direct comparison of R-values collected by different individuals using mechanical N-type Schmidt hammers, specifically. We then assess how no, light or heavy use of a carborundum puck to smooth rock surfaces affects resulting R-value data. Lastly, we compare two different R-value metrics on the same rock surface: R_mean (<i>n</i> = 30) versus ΔR (R_max − R_min of five consecutive R-values on the same spot). In all assessments, R_mean is similar for erratic surfaces with no and light surface treatment, and both are significantly lower than R_mean of surfaces with heavy treatment. Thus, we advise against the use of heavy surface treatment in SHD applications. We observe no relationship between inferred erratic age and either R_mean or ΔR, which could arise from inferred ages of erratics being inaccurate, from inferred ages of erratics being too similar or from measuring too few erratics from each landform.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"49 13","pages":"4077-4087"},"PeriodicalIF":2.8,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}