Katherine L. Maier, S. Nodder, Stacy Deppeler, Peter Gerring, Grace Frontin-Rollet, Rachel Hale, Oliver Twigge, Sarah J. Bury
{"title":"Dynamic near-seafloor sediment transport in Kaikōura Canyon following a large canyon-flushing event","authors":"Katherine L. Maier, S. Nodder, Stacy Deppeler, Peter Gerring, Grace Frontin-Rollet, Rachel Hale, Oliver Twigge, Sarah J. Bury","doi":"10.2110/jsr.2023.117","DOIUrl":null,"url":null,"abstract":"Submarine canyons are important deep-sea environments and conduits for transferring and accumulating sediment and organic matter and pollutants. Recent advances in observing, sampling, and analysing modern canyon sediment transport systems illustrate near-seafloor dynamics and highlight the potential roles of submarine canyons in transporting and storing organic carbon, nutrients, and contaminants in the deep sea, with implications for deep-sea ecosystems and global carbon budgets. Kaikōura Canyon, offshore northeastern Te Waipounamu South Island, Aotearoa New Zealand, is a benthic biomass hotspot that experienced an earthquake-triggered, canyon-flushing event in 2016. On return to the canyon in October 2020, benthic landers, with sediment traps at 2 m above the seafloor, were deployed along the canyon axis in approx. 900–1500 m water depths for a period of three weeks. These instrumented platforms provide a detailed view of near-seafloor sediment and organic carbon transport between canyon-flushing e vents, showing that the canyon environment hosts dynamic physical processes and short-term sediment fluxes and transport. Variations in sediment and organic carbon flux down-canyon and over time include small-scale sediment transport events, some of which are interpreted as turbidity currents, occurring on much shorter timescales than earthquake recurrence. We compare Kaikōura Canyon results with other longshore-fed, shelf-incised global submarine canyons and deep-ocean sites, revealing differences and likely multiple controlling factors for near-seafloor sediment flux. This Kaikōura Canyon high-resolution, benthic lander timeseries dataset highlights the complexity of submarine canyons and their role in organic carbon flux to the deep ocean, even under high present-day sea-level conditions. Evolving insights underscore the need for more observational data and samples to further quantify submarine canyon sediment and organic carbon transport and contribute to global evaluations of deep-sea canyon distribu tary systems.","PeriodicalId":17044,"journal":{"name":"Journal of Sedimentary Research","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Sedimentary Research","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.2110/jsr.2023.117","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Submarine canyons are important deep-sea environments and conduits for transferring and accumulating sediment and organic matter and pollutants. Recent advances in observing, sampling, and analysing modern canyon sediment transport systems illustrate near-seafloor dynamics and highlight the potential roles of submarine canyons in transporting and storing organic carbon, nutrients, and contaminants in the deep sea, with implications for deep-sea ecosystems and global carbon budgets. Kaikōura Canyon, offshore northeastern Te Waipounamu South Island, Aotearoa New Zealand, is a benthic biomass hotspot that experienced an earthquake-triggered, canyon-flushing event in 2016. On return to the canyon in October 2020, benthic landers, with sediment traps at 2 m above the seafloor, were deployed along the canyon axis in approx. 900–1500 m water depths for a period of three weeks. These instrumented platforms provide a detailed view of near-seafloor sediment and organic carbon transport between canyon-flushing e vents, showing that the canyon environment hosts dynamic physical processes and short-term sediment fluxes and transport. Variations in sediment and organic carbon flux down-canyon and over time include small-scale sediment transport events, some of which are interpreted as turbidity currents, occurring on much shorter timescales than earthquake recurrence. We compare Kaikōura Canyon results with other longshore-fed, shelf-incised global submarine canyons and deep-ocean sites, revealing differences and likely multiple controlling factors for near-seafloor sediment flux. This Kaikōura Canyon high-resolution, benthic lander timeseries dataset highlights the complexity of submarine canyons and their role in organic carbon flux to the deep ocean, even under high present-day sea-level conditions. Evolving insights underscore the need for more observational data and samples to further quantify submarine canyon sediment and organic carbon transport and contribute to global evaluations of deep-sea canyon distribu tary systems.
期刊介绍:
The journal is broad and international in scope and welcomes contributions that further the fundamental understanding of sedimentary processes, the origin of sedimentary deposits, the workings of sedimentary systems, and the records of earth history contained within sedimentary rocks.