Understanding the relationship between mobile bedforms and cable installations in the North Sea

A recurring issue for cable installations within territorial and offshore waters is the exposure of cables post installation and the subsequent need for external cable protection (e.g. Race Bank, BritNed, IFA2, Nemo, London Array). Mobile sediment bedforms (such as sandwaves and megaripples), which actively migrate across the seabed, have the potential to expose cables. In turn, cable exposure could result in scour (or secondary scour) and the removal of seabed sediments. Uncertainty regarding cable burial success and maintaining cable burial status for the lifetime of a project, needs to be addressed. the aims of this project are:

1. Literature review of current information on seabed mobility projects and outcomes.

2. Collation of current data available from developers.

3. Analysis of available data to identify seabed changes over time, bedform migration rates and trends in erosion/accretion.

4. Correlation of data and instances of cable exposure to ascertain patterns in the seabed changes and occurrences of cable exposure.

5. Categorise the seabed geomorphodynamics and sediment types.

6. Classify sediment mobilisation to facilitate predictions of future sediment distribution.

7. Ascertain whether other marine users (i.e. fisheries, aggregates) influence the requirement of external protection.

8. Provide recommendations as to how the outcomes of this project could be furthered in future projects.