Seasonal variations of glaciochemical, isotopic and stratigraphic properties in Siple Dome (Antarctica) surface snow

• Main Authors: Kreutz, Karl J., Mayewski, Paul A., Twickler, Mark S., Whitlow, Sallie I., White, J. W. C., Shuman, C. A., Raymond, C. F., Conway, H., McConnell, J. R.
• Format: Text
• Language: unknown
• Published: University of New Hampshire Scholars' Repository 1999
• Subjects: Siple; Siple Dome; West Antarctica; Antarc*; Antarctica
• Online Access: https://scholars.unh.edu/faculty_pubs/346; https://scholars.unh.edu/cgi/viewcontent.cgi?article=1345&context=faculty_pubs

Six snow-pit records recovered from Siple Dome, West Antarctica, during 1994 are used to study seasonal variations in chemical (major ion and H202), isotopic (deuterium) and physical stratigraphic properties during the 1988-94 period. Comparison of δD measurements and satellite-derived brightness temperature for the Siple Dome area suggests that most seasonal SD maxima occur within ±4 weeks of each 1 January. Several other chemical species (H2O2, non-sea-salt (nss) SO4 2-, methanesulfonic acid and NO3-) show coeval peaks with SD, together providing an accurate method for identifying summer accumulation. Sea-salt-derived species generally peak during winter/spring, but episodic input is noted throughout some years. No reliable seasonal signal is identified in species with continental sources (nssCa2+ nss Mg2+), NH4 + or nssCl-. Visible strata such as large depth-hoar layers (>5 cm) are associated with summer accumulation and its metamorphosis, but smaller hoar layers and crusts are more difficult to interpret. A multi-parameter approach is found to provide the most accurate dating of these snow-pit records, and is used to determine annual layer thicknesses at each site Significant spatial accumulation variability exists on an annual basis, but mean accumulation in the sampled 10 km2 grid for the 1988-94 period is fairly uniform.