Development of a high-end computational technology to predict meteotsunami impact

This project will develop a novel computational technology to predict meteotsunami impact in British coastal waters. It aligns with the EPSRC Theme "Living with Environmental Change", whose ambition is to develop "innovative solutions and technologies to protect against high impact extreme events such as flooding".

Meteotsunamis (meteorological tsunamis) are sudden and massive waves which are triggered by fast-moving storms far at sea. At first, a pressure burst whips up waves in the deep ocean. Then, resonant mechanisms between the weather front and the ocean amplify the wave height. As the wave move towards the coast, nearshore shelf resonances further feed it with energy. As a result, when a meteotsunami hits the coast, it can be as tall as 6 metres and can produce significant damage to harbours, boats and beaches, occasionally claiming human lives. It is obvious that protecting the coastline from meteotsunami impact is of economic and social interest.

In the UK, weather-induced monster waves are rare, but they do occur. For example, in 1892 a meteotsunami killed up to 60 people in Chesil Beach (Dorset). Recent observations have revealed that meteotsunamis are more common than originally thought. For example, in July 2015 a strong convective system generated a 1.25 m meteotsunami at Stonehaven harbour, which caused damage to boats and a serious injury to a crewman. In the future, meteotsunami frequency in the UK is likely to grow, because of increasing intensity of mid-latitude North Atlantic cyclones and rising sea levels, driven by global climate change.

Despite meteotsunamis posing a risk in the UK, their impact has never been quantified. As a matter of fact, it is practically impossible to forecast a meteotsunami in the UK with the current technology. This uses tsunami-like simulations in which the earthquake source is replaced with an atmospheric pressure source. This methodology has consistently failed in reproducing recorded meteotsunamis. The reason is that an earthquake only feeds energy into the tsunami for a short time, while the atmospheric source continuously modifies the meteotsunami waves. This results in meteotsunamis having peculiar propagation mechanisms that cannot be captured by existing tsunami-like models.

The core objective of this proposal is exactly to develop a novel and reliable technology to make meteotsunami prediction possible in the UK. The fact that no meteotsunami computational model has been ever validated in the UK scenario confirms the ambitious and timely nature of this project. The recent development by the applicant of a novel mathematical theory capable to capture the complex energy exchange between the atmosphere, the waves and the coast is a game-changing innovation that has the potential to enable us to achieve reliable meteotsunami predictions.

The goal of our project is to use the new technology to identify vulnerable regions in the UK, leading to safer coastal communities, harbours and beaches. We will also synthesise the computational results in practical engineering formulae, which will enable us to predict key meteotsunami parameters from atmospheric pressure data. Our new formulae will help coastal engineers to design more resilient coastal structures and infrastructures.

We are aware that warning systems are truly effective only if they involve the communities at risk. Therefore, we have designed a range of impact activities (e.g. online platform, social media feeds, information boards) to actively involve the public from the beginning. Our work has the potential to have an impact in shaping policies and public behaviour that will lead to safer coastal communities and beaches in the UK.

As discussed in the Pathways to Impact statement, we have identified the following potential impacts and their relevant stakeholders:

1. Impact on public policies and services. The research outputs of this project will show the importance of recording tidal gauge data in real time to predict meteotsunami inundation. Hence, this project will make a case for support to improve the UK tidal gauge recording system, which is set to record at 15 minute intervals. In the long term, this project will provide the knowledge base to deliver a new public service, i.e. a meteotsunami alert system. Stakeholders: Maritime Authorities, Royal Naval Lifeboat Institution (RNLI), Government.

2. Impact on practitioners and professional services. The project has the potential to inform changes to professional standards and guidelines in coastal engineering. This will be achieved with the definition of new return periods of short-time sea level oscillations, which can be used to design more resilient coastal structures. Stakeholders: Institution of Civil Engineers (ICE), engineering companies, consultancies.

3. Economic impact. The project is of interest to insurance companies which insure properties at sea (houses, boats, commercial activities etc.). By providing insurance companies with improved methods of meteotsunami risk assessment, the project has the potential to help them mitigate future losses. Stakeholders: insurance companies (e.g. AXA, Verisk Analytics).

4. Impact on society. The project has the potential to inform awareness and understanding of beach users, making them aware of the dangers associated with the passage of storms far at sea. This will shape public behaviour and will lead to safer coastal communities. Stakeholders: beach users, town councils.