ImproviNg coastal commUNity hazarD AssessmenT usIng nOvel experimeNts (INUNDATION)

Global sea level is rising and it is likely that the rate of rise will accelerate, significantly threatening coastal communities. The “low elevation coastal zone” (land 10% of total world GDP, contains trillions of dollars of coastal infrastructure and assets, and hosts rich and important marine ecosystems. Understanding future sea-level rise and coastal flood risk from storms and tsunamis is therefore of utmost socio-economic importance.

One of the risks to the coastal zone is a tsunami event. Recent tsunami events in the Indian Ocean (2004) and Japan (2011) resulted in over 300,000 fatalities and caused over 30 billion US$ of damage. However, neither event was unprecedented as both regions contain sedimentary deposits that indicate large historic and prehistoric tsunamis have previously occurred. Many other coastlines, such as the USA, Chile, the South China Sea, and Australia and even the UK, have a long history of tsunami events. The archive of these large events are the sediments left behind, however, we do not fully understand the processes behind their deposition due to the rare nature of the events themselves and the inconsistent preservation of tsunami deposits. This lack of understanding represents a critical impediment for forming accurate hazard assessments for extreme events that may only happen once every thousand years or more.

To tackle this problem a collaborative approach is required. Our established and early-career experts will conduct a pilot study, which aims to identify and quantify how tsunami deposits form using state-of-the-art laboratory experiments. We will focus on a series of experiments, with associated numerical modelling so we can understand the formation of these deposits and compare them to those found in the field.

Our objectives for our pilot project are:

O1: Perform unique laboratory experiments recording sediment movement under a tsunami wave. This project will use a 6m flume tank at the NERC Sorby Environmental Fluid Dynamics Laboratory, University of Leeds and build a suitable wave generator and beach profile to examine sediment behaviour during a tsunami-like wave.

O2: Conduct numerical experiments to increase our understanding of the physical processes occurring in the laboratory experiments.

O3: Compare the results to cores and field measurements from the Storegga tsunami (UK, ~8200 BP)

This project will identify key processes that form tsunami deposits and use that information in future grant proposals to NERC, EPSRC and Leverhulme.