Late Holocene climate change of Frederick Sound, British Columbia, Canada

Diatom abundances and flora were analyzed from late Holocene piston core VEC02A04 (∼990--5270 cal yr BP) from Frederick Sound, an anoxic fjord within the Seymour-Belize Inlet Complex, mid-coastal British Columbia. Q-mode cluster analysis resulted in identification of four clusters. Stratigraphic oscillation between cluster types and similar changes in overall diatom abundance down core reflected changes in precipitation and cloudiness on an ∼60 year cycle, similar to the periodicity of the Pacific Decadal Oscillation, which in turn reflects changes in the intensity and position of the Aleutian Low. Higher order grouping of clusters revealed five distinct successive climatic zones through the late Holocene of centennial to millennial duration, which are also interpreted to be linked to changes in the intensity and position of the Aleutian Low. Paleoclimatic interpretation of these zones indicate that the Frederick Sound area was dry and sunny between ∼5270--3820 cal yr BP, then wetter and cloudier till ∼3390 cal yr BP, back to drier and sunnier conditions up to ∼2770, and then reverted back to the present cloudy and wet neoglacial conditions up to at least ∼990 cal yr BP.