Journal
JOURNAL OF GLACIOLOGY
Volume 53, Issue 180, Pages 41-62Publisher
INT GLACIOL SOC
DOI: 10.3189/172756507781833901
Keywords
-
Ask authors/readers for more resources
The 3623 m long, 5C core collected at Vostok station, Antarctica, contains alternating layers of meteoric ice with two distinctly different microstructures. In this paper, we present the microstructure and impurity content of a number of specimens ranging in depth from 97 to 3416 m, describe in detail the characteristics of the different layers and propose a mechanism for their microstructural development. Digital image analysis, ion chromatography, scanning electron microscopy and energy dispersive X-ray spectroscopy were used to measure texture and the location and type of impurities; electron backscatter diffraction was used to determine crystal orientation. The ice associated with interglacial periods is characterized by relatively coarse grains and a strong preferred orientation of the c axes in a plane encompassing the coring direction, producing a vertical-girdle fabric. In contrast, ice from glacial periods is characterized by a much smaller grain size and a strong single-maximum fabric, where the c axes are clustered around the vertical. Calcium is uniquely present in the grain boundaries of the fine-grained glacial layers, and its effect on grain-boundary mobility and the misorientation dependence of mobility can explain the development of the discontinuous microstructure been in glacial ice at Vostok station.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available