Thomas Dhoop (2016)
Keywords: Thirding, storminess, middle ages, micro-XRF, sediment cores
Thirding Storms and Medieval History: Correlating historical sources with environmental proxy records using micro-XRF studies of sediment cores
It is a procedure archaeologists are particularly familiar with; two separate datasets are brought together with the expectation that through their synthesis a more comprehensive historical narrative will be produced. Yet, this does not always work out. Different spatial and temporal resolutions can throw a spanner in the works, causing datasets to not line up, or worse, they might appear to be contradicting one another. This paper will argue that this is not necessarily problematic. By ‘thirding’ the problem and working in the space between the two datasets – in other words through practice – new insights can still be produced, perhaps eventually leading to synthesis, or perhaps not.
This idea will be demonstrated by attempting to correlate a high-resolution dataset, historical sources describing storms, with a low-resolution but long-term dataset, an environmental proxy record for storminess. The concept is explored in medieval Winchelsea (East Sussex, UK) where written sources describing storm events – in 1230, 1250 and 1288 – are correlated with the GISP 2 Greenland ice core record of NA+ (sodium) concentrations between AD 1000 and 2000, an established proxy for storminess. This is done by subjecting a rhythmite sequence in a sediment sample, extracted from the ancient Winchelsea waterfront, to micro-XRF analysis using the ITRAX core scanner. The resulting geochemical proxy data is evaluated for indications of environmental change and in the process becomes an instrument to think about the effects of dynamisms in storminess on coastal communities, but also (maritime) technologies, connectivity and attitudes towards the sea.