Figures & data
FIGURE 1. Studied area and sampling sites for the cores Y4, N1, and Y2. In the top panel, marker A shows lakes, marker B shows network of meltwater channels. In the bottom panel, the contour interval is 10 m
FIGURE 2. (a) Sediment lithostratigraphy for the core Y4; (b) 210Pb, 137Cs versus depth in the sediment core G. Highest peak value of 137Cs corresponds to the 1965 fallout maximum from the atmospheric testing of nuclear weapons, in good agreement with the result of CRS 210Pb model (CitationSun et al., 2001b). (c) Linear depth-age model for the core G using the radiometric and calibrated ages, except one with an age of 666 cal. yr B.P. (G-08). The linear sedimentation rate (S) is 0.027 cm a−1
FIGURE 3. Concentrations of some elements versus depth in the Y4 lake sediments
FIGURE 4. R-cluster analysis result for the chemical elements in the Y4 lake sediments
FIGURE 5. Plots of element K versus Ba (A) and element ratio Al/Mg against Ba/Mg (B)
FIGURE 6. The change of penguin populations during the past ∼1300 years obtained by Q-factor analysis for the sediment core Y4 on the Ardley Island. The factor 2 is opposite to the factor 1; variation in loadings of factor 1 represents the variation in penguin population during the past 1300 years. At the top of the graph, the climatic optimum is based on the work of CitationSun et al. (2000), CitationSun and Xie (2001), CitationXie (2001), and CitationZhao (1991, Citation1997); the period of glacial advance is from CitationBarsch and Mäusbacher (1986); the Little Ice Age is derived from the work of CitationKreutz et al. (1997), CitationGoodwin (1998), CitationEmslie et al. (1998), CitationSmith et al. (1999), and CitationEmslie and McDaniel (2002). The abnormally warming climate period is from the work of CitationFraser et al. (1992), CitationStark (1994), CitationKing (1994), and CitationTurner et al. (2002). With regard to the correlation between the climatic change and penguin population fluctuation, see text for detailed discussion
TABLE 1 14C conventional and calibrated ages of the samples from G and Y4 lake sediment cores
TABLE 2 Chemical element concentrations in the proglacial sediments (N1), the local bedrocks, and the lake sediments Y4, Y2, and Xihu
TABLE 3 The correlation coefficients between the eight elements in the Y4 lake sediments
TABLE 4 The correlation coefficients between element Ba and lithological elements and bio-elements in the Y4 lake sediments
