Coastal erosion study could hold valuable lessons for climate change mitigation
The erosion rates of cliffs along the Sussex coast have rapidly sped up in the last 200 years, a new study has found.
The authors suggest that rising sea levels and increasingly severe storms have rapidly eroded the Beachy Head and Seaford Head shorelines. The loss of beach means that the cliffs are exposed to the eroding wave action forces, which is causing them to collapse into the sea. The researchers suggest this erosion process is probably happening along other coastlines in the UK and elsewhere around the world, with implications for how coasts will respond to climate change and what we can do to manage the impact on important coastal infrastructure.
|Dr Rood taking rock samples [Credit: Imperial College London]|
The scientists used a process called cosmogenic dating to learn how the chalk cliffs at Beachy Head and Seaford Head have eroded. Cosmogenic dating allows scientists to analyse the build-up of a rare isotope of beryllium (beryllium-10). This isotope is created when cosmic radiation reacts with oxygen atoms in the exposed flint rock, so by measuring its accumulation, it acts as a kind of 'rock clock' to show the rate of rock erosion.
|Eroded chalk with pieces of flint (the darker material), which the researchers analysed |
for levels of beryllium-10 [Credit: Imperial College London]
Dr Rood added: "Cosmogenic isotopes including beryllium-10 are advancing the science of retreating coastlines in Great Britain and worldwide. These new tools provide a rare insight into how dramatically environmental change and human impact affected sensitive coastal landscapes. We still need to better understand how other rocky coastlines have responded in the past, and cosmogenic isotopes are the key to unlocking this mystery."
The researchers now hope to use their observations to create a more accurate predictive model of how climate change will affect coastal erosion in the future, which could help authorities make more informed decisions about coastal management.
The research was published in the Proceedings of the National Academy of Sciences.
Author: Caroline Brogan | Source: Imperial College London [November 16, 2016]