“Testing regional synchronicity of abrupt climatic transitions during the last glacial-interglacial transition.”
With a prominent position at the North West tip of Europe, the British Isles have been at the forefront of Quaternary Ice Age cyclicity; and as a result of this positioning an extensive topographical and morphological legacy remains across much of the British and Irish landscape.
Of particular significance for the understanding of planetary dynamics, the last Glacial-Interglacial transition (LGIT), informally termed the ‘lateglacial’ and signifying the end of the last ice age, was a period characterised by a series of abrupt climatic oscillations and concomitant environmental instability. Clearly depicted in the annually resolved chronology of the GICC05 timescale, and echoed across the North Atlantic margin in a variety of depositional mediums; these oscillations are thought to have occurred at decadal and sub-decadal scaling’s, and in part driven by internal planetary factors, somewhat contrasting to the broader orbitally driven cycles characterising the large shifts in global climate during the last 2.6 million years. In Britain, such orbitally driven millennial-scale events have been well documented; however, the relative impact of these less pronounced and shorter-lived centennial to decadal scale events has yet to be fully quantified.
In line with the aims of the INTIMATE group, the scope of this project is to investigate and quantify the relative impact of shorter-lived centennial to decadal scale events in Scottish lacustrine deposits, and aims to begin to establish whether such events can be seen to lead or lag the Greenland stratotype.
The legacy of Scottish Quaternary research has yielded a wealth of information regarding the regional floristic signature, and local environmental fluxing. With comparatively recent developments in palaeoclimatic proxies, modes of analysis, and a better understanding of the subtleties of the lateglacial; a reinvestigation of some of these key sites, in conjunction with newly identified depositional basins will help to build a more coherent picture of such a dynamic and climatologically important phase in recent geologic past.
The preliminary work of the PhD has identified 3 lateglacial sites distributed across the West Scottish coastline, giving a broad North/South transect. The 3 sites, Crudale Meadow, Tanera Mor, and Little Lochans will hopefully provide an insight into gradients of change and regional synchronicity, both in a geographic and temporal context. Furthermore an assessment of the relative influence of the North Atlantic as a driver of climatic change during this period can be tested.
This work builds upon one aspect of the CQR, which has historically had a strong Scottish orientation. In many cases advancements in the discipline have in part been made via the study of Scottish lacustrine deposits. Such notable developments have included the microscale analyses of glaciolacustrine varve sediments (Palmer et al 2010; Palmer et al 2011); improvements in tephra extraction methods, tephrochronology and the tephrostatigraphic framework of the late glacial (e.g. Blockley et al 2005; Matthews et al 2011); as well as the adoption of more robust modes of statistical analysis i.e. Bayesian statistics for the construction of age depth models (e.g. Lowe and Walker 2000; Blockley et al 2004).
Focus here will be on palaeoclimatic proxies which are able to yield quantitative estimates of palaeoclimate (i.e. Chironomid and O-Isotope derived summer temperatures), as well as tephrostratigraphy as a means to correlate basins with wider research.