ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 05.04. Instrumentation and techniques of general interest  (1)
  • continental margins  (1)
Collection
Keywords
Publisher
Language
Years
  • 1
    Publication Date: 2023-11-23
    Description: Offshore meteoric groundwater (OMG) has long been hypothesized to be a driver of seafloor geomorphic processes in continental margins worldwide. Testing this hypothesis has been challenging because of our limited understanding of the distribution and rate of OMG flow and seepage, and their efficacy as erosive/destabilizing agents. Here we carry out numerical simulations of groundwater flow and slope stability using conceptual models and evolving stratigraphy—for passive siliciclastic and carbonate margin cases—to assess whether OMG and its evolution during a late Quaternary glacial cycle can generate the pore pressures required to trigger mechanical instabilities on the seafloor. Conceptual model results show that mechanical instabilities using OMG flow are most likely to occur in the outer shelf to upper slope, at or shortly before the Last Glacial Maximum sea‐level lowstand. Models with evolving stratigraphy show that OMG flow is a key driver of pore pressure development and instability in the carbonate margin case. In the siliciclastic margin case, OMG flow plays a secondary role in preconditioning the slope to failure. The higher degree of spatial/stratigraphic heterogeneity of carbonate margins, lower shear strengths of their sediments, and limited generation of overpressures by sediment loading may explain the higher susceptibility of carbonate margins, in comparison to siliciclastic margins, to mechanical instability by OMG flow. OMG likely played a more significant role in carbonate margin geomorphology (e.g., Bahamas, Maldives) than currently thought.
    Description: Plain Language Summary: The flow of fresh to brackish groundwater has been proposed as an important process shaping the seafloor. However, we still have a poor understanding of how groundwater behaves in the sub‐seafloor and whether it can erode seafloor sediments. In this study, we test this hypothesis by using conceptual and realistic numerical models of two common types of seafloor margins—siliciclastic and carbonate—to assess the role of groundwater in making the seafloor susceptible to erosion. We show that the flow of groundwater offshore could have driven seafloor erosion close to the shelf break during the Last Ice Age, when sea level was lower than at present. Carbonate margins are more susceptible to this type of failure than siliciclastic margins. This may be explained by the higher variability in sediment properties across carbonate margins as well as the lower strength of their sediments. Groundwater has likely played an important role in shaping the seafloor in carbonate margins, and it may be responsible for landforms such as canyons, scars, and depressions in the Bahamas and the Maldives.
    Description: Key Points: Offshore meteoric groundwater (OMG) flow can drive mechanical instabilities in the outer shelf to upper slope. Such instabilities occur at, or shortly after, the Last Glacial Maximum sea‐level lowstand. Carbonate margins are more susceptible to mechanical instability by OMG than siliciclastic margins.
    Description: European Research Council http://dx.doi.org/10.13039/501100000781
    Description: National Science Foundation http://dx.doi.org/10.13039/100000001
    Description: https://doi.org/10.5281/zenodo.7094202
    Description: https://www.rocscience.com/software/slide2
    Description: https://figshare.com/s/5336d42d19ef771d4ad8
    Description: https://figshare.com/s/5027cd5ca22a7e96b3d1
    Keywords: ddc:551.3 ; offshore groundwater ; mechanical instability ; continental margins ; seafloor geomorphology ; siliciclastic ; carbonate
    Language: English
    Type: doc-type:article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2024-01-29
    Description: Recent advances in underwater and airborne robotic systems and ocean technologies have opened new perspectives in marine geology and its applications in the context of coastal and marine economic activities, whose sustainable development is increasingly acknowledged as a pillar for the new blue economy. BridgET (Bridging the gap between the land and the sea in a virtual Environment for innovative Teaching and community involvement in the science of climate change-induced marine and coastal geohazard) is an EU ERASMUS+ project designed to develop innovative and inclusive teaching methods to address a growing demand for strategic skills and scientific expertise in the field of 3D geological mapping of coastal environments. Seamless integration of the wide variety of multisource and multiscale onshore, nearshore and offshore geospatial data is indeed one of the main areas for improvement in the implementation of efficient management practices in coastal regions, where climate change, rising sea level, and geohazards are considerable environmental issues. BridgET involves a partnership consisting of six European universities with outstanding expertise in the study of geological hazards, and climate impacts in marine and coastal areas (i.e., University of Milano-Bicocca, Italy, Arctic University of Tromsø/CAGE - Norway, National and Kapodistrian University of Athens - Greece, Kiel University, Germany, University of Liege – Belgium, and the University of Malta), two Italian research institutes (INGV and INAF) and a German company (Orthodrone GmvH) specialized in UAS-based LiDAR and photogrammetry data acquisition services and analyses. Project implementation relies on delivering learning and teaching activities through dedicated summer schools for MSc students by efficiently combining the partner’s expertise. Schools focus on giving students a hands-on experience with the variety of methods and procedures adopted in geospatial data acquisition and processing, including the use of drones (Uncrewed Aerial System – UAS), acoustic remote sensing techniques and underwater robotic systems, together with the progress made by computer visions and digital image analysis by using Artificial Intelligence (AI). Students are also introduced to the opportunity to easily examine multiple viewing angles of the seabed and coastal 3D surfaces by using immersive and nonimmersive Virtual Reality (VR), to bring them closer to a more straightforward observation of geomorphological data and geological phenomena. The first Summer School was held in Santorini between the 3rd and 14th of October, 2022. It was attended by 26 students coming from 13 different countries. Teaching and learning activities included several classrooms, fieldwork, laboratory sessions, and seven seminars and cultural visits dealing with transversal topics, allowing students to approach an integrated understanding of human interaction with physical processes from social and economic perspectives. In this presentation, we give examples of course content used to allow students to develop a deeper understanding of theoretical and practical knowledge of climate-induced coastal and marine geohazards. Participants' opinions on the quality of the offered learning/training activities of the Erasmus+ BridgET Santorini Summer School (collected through a dedicated questionnaire) will also be presented. Erasmus+ BridgET Team: Varvara Antoniou, Fabio Luca Bonali, Clara Drummer, Theynushya Esalingam, Luca Fallati, Susanna Falsaperla, Felix Gross, Hans-Balder havenith, Juri Klusak, Sebastian Krastel, Iver Martens, Aaron Micallef, Paraskevi Nomikou, Giuliana Panieri, Danilo Reitano, Julian Teege, Alessandro Tibaldi, Andrea Giulia Varzi, Fabio Vitello, Othonas Vlasopoulos
    Description: Published
    Description: Vienna (Austria)
    Description: OSA4: Ambiente marino, fascia costiera ed Oceanografia operativa
    Keywords: marine geosciences ; education ; Europe ; 04.02. Exploration geophysics ; 05.03. Educational, History of Science, Public Issues ; 05.04. Instrumentation and techniques of general interest
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Conference paper
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...