{"title":"Size-dependent asymmetry of barchans indicates dune growth controlled by basal area or bulk volume","authors":"Dominic T. Robson, Andreas C. W. Baas","doi":"10.1002/esp.5876","DOIUrl":null,"url":null,"abstract":"<p>We introduce a novel analytical model of the growth of barchan dunes in terms of their two flanks, from which we derive expressions for the size-dependence of the bilateral asymmetry of these bedforms in three cases where different mechanisms dominate the growth process. Analysis of the morphology of barchans on Mars and Earth suggest that there may exist two distinct attractor states for the asymmetry distribution. By comparing our analytical results with the observations, we show that the growth of barchan dunes appears to be dominated by processes, which are proportional to the basal area or volume of the bedforms, rather than being linear to their width as is typically assumed. We propose hypotheses explaining area-dominated growth as a result of variable wind regimes and volume-dominated growth from collisions. These predictions appear to be in line with the available data for the terrestrial swarms and barchan-like submarine bedforms and offer the potential of predicting patterns in inaccessible wind regimes from data on the morphology of the dunes.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.5876","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Earth Surface Processes and Landforms","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/esp.5876","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOGRAPHY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
We introduce a novel analytical model of the growth of barchan dunes in terms of their two flanks, from which we derive expressions for the size-dependence of the bilateral asymmetry of these bedforms in three cases where different mechanisms dominate the growth process. Analysis of the morphology of barchans on Mars and Earth suggest that there may exist two distinct attractor states for the asymmetry distribution. By comparing our analytical results with the observations, we show that the growth of barchan dunes appears to be dominated by processes, which are proportional to the basal area or volume of the bedforms, rather than being linear to their width as is typically assumed. We propose hypotheses explaining area-dominated growth as a result of variable wind regimes and volume-dominated growth from collisions. These predictions appear to be in line with the available data for the terrestrial swarms and barchan-like submarine bedforms and offer the potential of predicting patterns in inaccessible wind regimes from data on the morphology of the dunes.
期刊介绍:
Earth Surface Processes and Landforms is an interdisciplinary international journal concerned with:
the interactions between surface processes and landforms and landscapes;
that lead to physical, chemical and biological changes; and which in turn create;
current landscapes and the geological record of past landscapes.
Its focus is core to both physical geographical and geological communities, and also the wider geosciences