ENVS 319 Assignment 2: Research proposal
An investigation of climate and human activities as constraints for reliability of lake sediment archives in relation to Lake St Lucia Introduction
Lake sediment archives are viewed as exceptional as they contain variety of other materials suspended in it that are useful for palaeoclimatic studies (von Gruten et al, 2012; Smol, 2002). These can be referred to as multi-proxy analysis with the most common proxy occurring in sediment being fossil pollen. Lake sediments archives are obtained by drilling using a coring device such as gravity corer. Lake sediment archives have been the fascination of researchers of the Northern hemisphere and the tropics because of water availability, there are more lakes to study the lake sediments than the Southern hemisphere. Whereas the Southern hemisphere as whole lack studies on lake sediment archives, especially the arid to semi-arid southern Africa, this has resulted in inconclusive and discontinuous paalaeoclimatic records with low spatial resolution (Neumann et al, 2008). South Africa is no exception from scarcity of palaeoclimatic records, hence numerous palaeoclimatic studies have dwelled on springs and swamps (Neumann et al, 2008). Therefore the available palaeoclimatic have low spatial resolution such as the fossil pollen of St Lucia which is > 45000 year old also AMS dating reveal weak correlations of this the Holocene climate record (Neumann et al, 2008; Finch, 2005). Since the east coast of South Africa is relatively wetter due the presence of warm Mozambique current, most lake sediment archives used for palaeoclimate reconstruction are from the KwaZulu-Natal eastern coastline such as the Lake St Lucia estuarine lake which is the focus of this study. The lake St Lucia receives a mean precipitation of about 1000 mm on a yearly basis which is expected for a substantially subhumid eastern coastline of South Africa (Bate and Taylor, 2008). In...