rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Assessing methane emissions from an offshore marine aggregate extraction site near Sylt, Eastern North Sea
  name:
    name part: Schmidt, Martina
    name part: 1968-
    role:
      role term: creator
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Bussmann, Ingeborg
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Reith, Sarah J. E.
    name part: 2001-
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Palzer, Annika
    name part: 2002-
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Couret, Cedric
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Keppler, Frank
    name part: 1967-
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Polag, Daniela
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Sander, Lasse
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Schroll, Moritz
    name part: 1992-
    role:
      role term: VerfasserIn
    role:
      role term: aut
  name:
    name part: Wietzel, Julia B.
    name part: 1996-
    role:
      role term: VerfasserIn
    role:
      role term: aut
  type of resource: text
  origin info:
    place:
      place term: xx
    date issued: 2025
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 22
  abstract: Abstract. Coastal regions are estimated to contribute with up to 1 % to the global atmospheric methane (CH4) budget. However, these emissions remain highly uncertain due to strong spatial and temporal variability. Anthropogenic activities in coastal waters, such as sand mining and beach nourishment, have not yet been investigated or included in the calculation of the resulting greenhouse gas emissions. Since 1984, regular beach nourishment has been carried out every summer on the west coast of the island of Sylt (North Sea, Germany). During this process, dredging vessels extract a mixture of sand and water from the seabed of a spatially confined area (Westerland II), situated approximately 8 km off the coast and deposit the material on the western beach and foreshore of Sylt. High resolution measurements of CH4 in ambient air at the coastal atmospheric station Westerland (Sylt, Germany) show CH4 spikes of up to 400 ppb above background concentrations. These spikes occurred mainly during summer season, during low tide and under westerly wind conditions (from the sand dredging area). To investigate the origin of the observed atmospheric CH4 spikes, combined in-situ measurements of dissolved and atmospheric CH4 together with water sampling, were performed on board the research vessel RV Mya II (AWI) along a coastal transect from Sylt to the Westerland II dredging site. In the vicinity of the dredging site, elevated CH4 concentrations were detected both in ambient air (400–500 ppb above background reaching up to 2450 ppb) and in surface and bottom waters (69–90 nmol L-1). This resulted in a mean diffusive flux of 45 ± 47 µmol m-2 d-1 with a maximum value of 340 µmol m-2 d-1 in the dredging area, in contrast to a diffusive flux of 3.0 ± 3.6 µmol m-2 d-1 during the transit. Our observations demonstrate significantly higher CH4 concentrations and fluxes in both the atmosphere and the water column above the sand dredging site, compared to the areas outside the dredging acti…
  note: Martina Schmidt, Ingeborg Bussmann, Sarah J.E. Reith, Annika Palzer, Cedric Couret, Frank Keppler, Daniela Polag, Lasse Sander, Moritz Schroll, Julia B. Wietzel
  note: Gesehen am 15.07.2026
  classification: 31
  related item:
    title info:
      title: Assessing methane emissions from an offshore marine aggregate extraction site near Sylt, Eastern North Sea [data]
    name:
      name part: Schmidt, Martina, 1968 -
    origin info:
      publisher: Heidelberg : Universität, 2026
    physical description:
      extent: 1 Online-Ressource (3 Files)
    identifier: (DE-627)1978673477
  related item:
    title info:
      title: EGUsphere
    name:
      name part: Assessing methane emissions from an offshore marine aggregate extraction site near Sylt, Eastern North Sea
    origin info:
      publisher: Göttingen : Copernicus GmbH, 2022
    physical description:
      extent: Online-Ressource
    identifier: (DE-627)1794707824
    identifier: (DE-600)3111974-8
    part:
      text: (2025), Artikel-ID 4850, Seite 1-22
  related item:
    name:
      name part: Assessing methane emissions from an offshore marine aggregate extraction site near Sylt, Eastern North Sea
    part:
      text: year:2025
    part:
      text: elocationid:4850
    part:
      text: pages:1-22
    part:
      text: extent:22
  identifier: https://doi.org/10.5194/egusphere-2025-4850
  identifier: https://egusphere.copernicus.org/preprints/2025/egusphere-2025-4850/
  record info:
    record content source: DE-627
    record creation date: 260715
    record change date: 20260715202338.0
    record identifier: 1978680376
    language of cataloging:
      language term: ger