Abstract
Spectral reflectance of a green iceberg confirms that the color is inherent to the ice, not an artifact of the illumination. Pure ice appears blue owing to its absorption of red photons. Addition of a constituent that absorbs blue photons can shift the peak reflectance from blue to green. Such a constituent was identified by spectrophotometric analysis of core samples from this iceberg and from the Amery basal ice, and of seawater samples from Prydz Bay. Analysis of the samples by fluorescence spectroscopy indicates that the blue absorption, and hence the inherent green color, is due to the presence of marine-derived organic matter in the green iceberg, basal ice, and seawater. Thick accumulations of green ice, in icebergs and at the base of ice shelves, indicate that high concentrations of organic matter exist in seawater for centuries at the depth of basal freezing. -from Authors
Original language | English |
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Pages (from-to) | 6921-6928 |
Number of pages | 8 |
Journal | Journal of Geophysical Research: Oceans |
Volume | 98 |
Issue number | C4 |
DOIs | |
Publication status | Published - 1993 |