|Title:||On the impact of impurities on firnification and gas entrapment in Antarctic firn|
|Author:||Gregory, S., Albert, M.R. and Baker, I.|
|Periodical:||American Geophysical Union, Fall Meeting 2012, abstract #C51B-0780|
The influence of impurities on the microstructure of polar firn may affect the nature of post-depsitional metarmophism in the firn column and consequently the entrapment of atmospheric gases. Impacts from variations in impurity type and concentration can be seen through comparison of two Antarctic sites of different accumulation rates. Understanding how firn microstructure changes as a function of impurity concentration provides insight into how and when bubbles are most likely to form and trap gas within the firn column. Measurements of impurity concentrations and type were done on both fine and coarse grain firn samples from WAIS Divide and Megadunes. The relationships observed between impurity concentration, impurity type, density, and permeability are described.