Freya Barr , Charlotte F.K. Uphues , Graziela Miot da Silva , Patrick A. Hesp
{"title":"石灰岩礁上振荡和单向流动动力学的观测","authors":"Freya Barr , Charlotte F.K. Uphues , Graziela Miot da Silva , Patrick A. Hesp","doi":"10.1016/j.margeo.2025.107640","DOIUrl":null,"url":null,"abstract":"<div><div>Natural and human made reef structures provide effective coastal protection by attenuating incident wave and current energy. Anticipated effects of climate change, such as sea level rise, threaten coastal zones and are predicted to reduce the protection provided to coastlines by reef structures. This study aims to investigate wave and current dynamics at a limestone reef site at Robe, South Australia, to improve our understanding of how limestone reefs act as protective reef structures in present-day and in changing climate conditions. Pressure sensors and acoustic doppler current profilers were deployed on a cross-reef transect to investigate rates of wave attenuation, shifts in spectral wave energy, and changes to current speed and direction. Field measurements indicate that the Town Beach reef acts as a tidally modulated low-pass filter, attenuating more wave energy at lower water levels compared to higher water levels. Despite attenuating less wave energy than other reported studies, the Town Beach reef effectively dissipates approximately 42 % of gravity wave energy, resulting in a domination of lower frequency, infragravity wave energy within the landward reef-protected lagoon. Current speeds landward of the reef are approximately one third lower than those observed seaward of the reef. Bidirectional flows (north-south and east-west, respectively) occur at higher water levels, changing to unidirectional flows (south and west, respectively) at lower water levels. Potential reasons for these observed dynamics are discussed, and future research is proposed to address key limitations, such as unknown ecological, geometric, and morphologic aspects of the reef.</div></div>","PeriodicalId":18229,"journal":{"name":"Marine Geology","volume":"489 ","pages":"Article 107640"},"PeriodicalIF":2.2000,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Observations of oscillatory and unidirectional flow dynamics over a limestone reef\",\"authors\":\"Freya Barr , Charlotte F.K. Uphues , Graziela Miot da Silva , Patrick A. Hesp\",\"doi\":\"10.1016/j.margeo.2025.107640\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Natural and human made reef structures provide effective coastal protection by attenuating incident wave and current energy. Anticipated effects of climate change, such as sea level rise, threaten coastal zones and are predicted to reduce the protection provided to coastlines by reef structures. This study aims to investigate wave and current dynamics at a limestone reef site at Robe, South Australia, to improve our understanding of how limestone reefs act as protective reef structures in present-day and in changing climate conditions. Pressure sensors and acoustic doppler current profilers were deployed on a cross-reef transect to investigate rates of wave attenuation, shifts in spectral wave energy, and changes to current speed and direction. Field measurements indicate that the Town Beach reef acts as a tidally modulated low-pass filter, attenuating more wave energy at lower water levels compared to higher water levels. Despite attenuating less wave energy than other reported studies, the Town Beach reef effectively dissipates approximately 42 % of gravity wave energy, resulting in a domination of lower frequency, infragravity wave energy within the landward reef-protected lagoon. Current speeds landward of the reef are approximately one third lower than those observed seaward of the reef. Bidirectional flows (north-south and east-west, respectively) occur at higher water levels, changing to unidirectional flows (south and west, respectively) at lower water levels. Potential reasons for these observed dynamics are discussed, and future research is proposed to address key limitations, such as unknown ecological, geometric, and morphologic aspects of the reef.</div></div>\",\"PeriodicalId\":18229,\"journal\":{\"name\":\"Marine Geology\",\"volume\":\"489 \",\"pages\":\"Article 107640\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2025-08-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Marine Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0025322725001653\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Marine Geology","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0025322725001653","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Observations of oscillatory and unidirectional flow dynamics over a limestone reef
Natural and human made reef structures provide effective coastal protection by attenuating incident wave and current energy. Anticipated effects of climate change, such as sea level rise, threaten coastal zones and are predicted to reduce the protection provided to coastlines by reef structures. This study aims to investigate wave and current dynamics at a limestone reef site at Robe, South Australia, to improve our understanding of how limestone reefs act as protective reef structures in present-day and in changing climate conditions. Pressure sensors and acoustic doppler current profilers were deployed on a cross-reef transect to investigate rates of wave attenuation, shifts in spectral wave energy, and changes to current speed and direction. Field measurements indicate that the Town Beach reef acts as a tidally modulated low-pass filter, attenuating more wave energy at lower water levels compared to higher water levels. Despite attenuating less wave energy than other reported studies, the Town Beach reef effectively dissipates approximately 42 % of gravity wave energy, resulting in a domination of lower frequency, infragravity wave energy within the landward reef-protected lagoon. Current speeds landward of the reef are approximately one third lower than those observed seaward of the reef. Bidirectional flows (north-south and east-west, respectively) occur at higher water levels, changing to unidirectional flows (south and west, respectively) at lower water levels. Potential reasons for these observed dynamics are discussed, and future research is proposed to address key limitations, such as unknown ecological, geometric, and morphologic aspects of the reef.
期刊介绍:
Marine Geology is the premier international journal on marine geological processes in the broadest sense. We seek papers that are comprehensive, interdisciplinary and synthetic that will be lasting contributions to the field. Although most papers are based on regional studies, they must demonstrate new findings of international significance. We accept papers on subjects as diverse as seafloor hydrothermal systems, beach dynamics, early diagenesis, microbiological studies in sediments, palaeoclimate studies and geophysical studies of the seabed. We encourage papers that address emerging new fields, for example the influence of anthropogenic processes on coastal/marine geology and coastal/marine geoarchaeology. We insist that the papers are concerned with the marine realm and that they deal with geology: with rocks, sediments, and physical and chemical processes affecting them. Papers should address scientific hypotheses: highly descriptive data compilations or papers that deal only with marine management and risk assessment should be submitted to other journals. Papers on laboratory or modelling studies must demonstrate direct relevance to marine processes or deposits. The primary criteria for acceptance of papers is that the science is of high quality, novel, significant, and of broad international interest.