A team of international researchers is studying the evolution of the sea level curve and the record of tsunamis in the North Sea over the last 10,000 years, the University of Coimbra (UC) revealed.
According to a note from the UC, this project aims improve understanding of tsunami risk in the North Seaidentifying geological signatures of tsunamis in coastal areas and heading towards the seabed.
Pedro Costa, professor at the Department of Earth Sciences (DCT) of the Faculty of Science and Technology of the University of Coimbra (FCTUC), is the coordinator of the NORSEAT project at UC.
“The aim is to gather evidence of events, group terrestrial and marine archives to establish the dynamics of the main events and, finally, establish the evolution of the relative sea level curve of the Shetland Islands,” says Pedro Costa, quoted in the note.
These data are essential for developing more rigorous risk assessments and flood projectionsthe professor added.
UC also found that tsunamis are relatively rare in the North Sea basin, with the best-known example being the Storegga tsunami, triggered by a large submarine landslide on the Norwegian continental shelf 8,200 years ago, which left a sedimentary imprint of this great flood in several coastal locations in the North Atlantic and the North Sea.
Pedro Costa explained that the tests, recently determined, suggest a very low recurrence rate, on a geological scale, of tsunami events in the region.
“However, due to the nature of the North Sea basin and its coasts, characterised by limited sedimentary accommodation space, poor preservation of deposits from extreme events and anthropogenic erosion or reworking, we have seen a likely underestimation of tsunami risk for the entire Atlantic Basin.”
For Pedro Costa, the sedimentary archives of tsunamis detected on the seabed are of vital importance to improve the understanding of the danger of tsunamis in the North Sea.
Furthermore, “knowledge of the relative sea level position at the time when tsunamis inundated coastal areas is crucial for modelling and sediment transport for flood scenarios, which will allow for better risk assessments to be developed.”
In this way, researchers are tracing tsunami deposits, studying their extent and characteristics in detail, and checking whether the marine record contains evidence of more events, providing new insights into the intervals of occurrence.
“On the other hand, they seek to reconstruct the relative sea level curve for the Holocene, which until now has been poorly restricted for the Shetland Islands, thus evaluating with greater precision the heights of the paleotsunamis,” highlighted the UC.
Source: Observadora
