Palaeoceanography: marine environments of the past and the establishment of long baselines

Paul Butler (Bangor), Stella Alexandroff (Bangor), James Scourse (Bangor) & Catriona Purcell  (Bangor), David Reynolds (Cardiff),  Bill Austin (St Andrews) 

Time series of ocean observations are inherently limited. Observations with good spatial coverage have very short timescales, of the order of a few decades at most. Longer records exist, but are sparse, and even these are generally no more than about one hundred years in length. These limitations present a fundamental challenge, because the historical period covered by modern instrumental observations is also a period of rapid environmental change; the combination of anthropogenic climate change, industrial activities in the shelf seas and intensive fisheries have generated a marine environment that is very likely anomalous in the context of past centuries.

The establishment of long baselines is essential to contextualise present day ocean observations. In this session we will showcase recent advances in the use of proxy archives to investigate marine environmental variability in the past.  In particular we will present (i) very high resolution proxy records of North Atlantic climate during the past few centuries that make use of the geochemistry of the annually banded shells of very long-lived bivalve molluscs; and (ii) records from marine sediment cores of ocean variability during deglaciation and throughout the Holocene.