Hydrodynamic modelling of sediment transport and bedform formation on the NW Irish shelf

  • William Evans

Student thesis: Doctoral Thesis

Abstract

Much of our knowledge of sediment transport on the northwest Irish shelf was hypothesised in the 1970's with limited resources and without the benefit of modern seafloor mapping equipment and techniques (Kenyon and Stride, 1970). Utilising existing and newly generated data sets, this research focuses on modern sediments located on the north Irish shelf between 54° - 56°N the aim of which is to establish connections between bedform morphology, sediment distribution and modelled hydrodynamics in order to describe sediment transport processes from a shelf to bedform scale.

Interrogation of multibeam echosounder data has enabled classification of 8 depositional and 2 erosional bedform types (Evans et al., 2015). Many of these bedforms overlap those glacial formations identified in previous research (Benetti et al., 2010b, Dunlop et all., 2011, O'Cofaigh et al., 2012).

Classification of back scatter data has identified 5 sedimentary classes across the shelf, with gravel dominating the inshore areas and large soft sediment deposits concentrated in proximity to moraine features and areas of bathymetric lows.

These mapping techniques applied alongside outputs from a sediment transport specific, hydrodynamic model created as part of this research, have led to a number of novel findings and challenges to existing research.

The location of bedload parting zones presented by (Belderson et al., 1982) are challenged and a new location suggested based on bedform distribution, bedform geometry and modelled current data.
Date of AwardMay 2018
LanguageEnglish
Awarding Institution
SponsorsDepartment of Education and Learning
SupervisorDerek Jackson (Supervisor) & Sara Benetti (Supervisor)

Keywords

  • Sediment
  • Multibeam Echosounder
  • Hydrodynamics
  • Seafloor mapping

Cite this

Hydrodynamic modelling of sediment transport and bedform formation on the NW Irish shelf
Evans, W. (Author). May 2018

Student thesis: Doctoral Thesis