LATE HOLOCENE SEA-LEVEL CHANGE AND SALINE INTRUSION, HUMBER ESTUARY, UK

Changing sea-levels are a key issue around the globe due to the direct and indirect effects of predicted climate change on coastal regions and resources. This has resulted in particular concerns over the preservation of potable and plentiful water supplies from chalk aquifers in coastal areas. Understanding the risk of saline intrusion into coastal aquifers requires consideration of both the sea-level history of the area, as well as the groundwater characteristics of the surrounding region.

This project will produce sea-level data for the late Holocene from the Humber Estuary, on the eastern UK coast, elucidating the history of sea-level change, and thus providing an insight into current and possible future trends.

Existing sea-level data points for the estuary provide a record of change during the early and mid Holocene, however there is a scarcity of data for the most recent ~2000 years. This project will establish a high resolution sea-level record for this period from the Humber Estuary through litho- and bio-stratigraphical analyses of sediment cores taken from locations around the estuary. Microfossils, primarily diatoms, will be used as the proxy data to reconstruct former relative sea-levels.

Presently active and buried saltmarshes are key sites for such reconstructions due to their potential to store records of past sea-level changes. However, utilising such sites is a particular challenge in this research due to the impact of anthropogenic activities in and around the Humber Estuary over the last few centuries. These impacts include the reclamation of marshland, as well as the construction of embankments surrounding the estuary margin; this has altered the development and preservation of saltmarshes throughout the estuary.

The production of late Holocene sea-level data from this project will further understanding of the Holocene evolution of the Humber Estuary, the implications of saline intrusion into an aquifer, and the consequences of possible future changes. Through working with the local water authority, the data can also be used to inform decisions, policies and management strategies to safeguard future water supplies for the region.