Long-wavelength optical logging for high-resolution detection of ash layers in glacier ice

A new instrument for high-resolution optical logging has been built and tested in Antarctica. Its purpose is to obtain records of volcanic products and other scattering features, such as bubbles and impurities, preserved in polar ice sheets, and it achieves this by using long wavelength near-infrare...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: WING S. CHAN, MERLIN L. MAH, RYAN C. BAY, JOSEPH J. TALGHADER
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press 2017
Subjects:
ash
Online Access:https://doi.org/10.1017/jog.2016.105
https://doaj.org/article/6df6b6a1ca6941aa8694441411aa0cf3
Description
Summary:A new instrument for high-resolution optical logging has been built and tested in Antarctica. Its purpose is to obtain records of volcanic products and other scattering features, such as bubbles and impurities, preserved in polar ice sheets, and it achieves this by using long wavelength near-infrared light that is absorbed by the ice before many scattering events occur. Longer wavelengths ensure that the return signal is composed primarily of a single or few backscattering event(s) that limit its spatial spread. The compact optical logger features no components on its body that draw power, which minimizes its size and weight. A prototype of the logger was built and tested at Siple Dome A borehole, and the results were correlated with prior optical logging profiles and records of volcanic products from collected ice core samples.