Aidan Wrethman

Active research projects:

In the transition to a low carbon UK economy, the safety of critical energy infrastructure is paramount. Many of these facilities are in exposed coastal regions and their vulnerability to extreme coastal change, and particularly storms and tsunami flood risk, is a major area of concern for national energy security. Recent geological evidence reveals a series of tsunamis having struck parts of the UK coastline with recurrence of less than 1:10,000 yrs. with a range of different source mechanisms, such as offshore earthquakes and submarine landslides. The largest and most destructive event was a tsunami that occurred across the North Atlantic 8200 yr ago caused by one of the world’s largest submarine landslides (the Storegga Slide) that took place on the continental slope west of Norway. The inventory of past tsunamis to have struck parts of the UK coastline is well-established, however, the maximum flood elevations reached by these tsunami waves are not well reconstructed. This is due to a poor understanding of the altitude of relative sea level at the time that the tsunami struck especially in the northern Isles (Orkney and Shetland) as well as information focused on the sediments rather than the waves in previous studies. High resolution sedimentology including micro Ct, sediment coring, geophysical survey interpretation & chronology will be used to examine offshore and onshore sediment cores from the North Atlantic continental shelf and slope which are likely to contain sedimentary evidence for past tsunamis. Sites across the Shetland Islands as well as detailed sedimentological study at sites around the Montrose Basin, lie close to marine infrastructure and will yield information on the sea level context of the tsunami sediments to allow a more detailed reconstruction of flood elevations at the site level. In addition to the field-based research, a set of parametric experiments using a tsunami wave flume will consider how flood inundation depths at the coastline are dependent on tsunami wave characteristics and the detail surrounding variability of local and regional bathymetry as well as coastal configuration. This project will provide valuable information on the safety or otherwise of nuclear, oil and gas and newly emerging renewables infrastructure across the UKCS.