Submitted by Anonymous on Thu, 08/14/2008 - 04:22
Forums
High Arctic Change 08

I understand that the ice cores from the glacier are melted down then stored at a cool temperature.  Are the cores sectioned (cut) before they are melted so that the depth is noted before the oxygen isotope readings are taken or is depth of no concern. Also at what temperature does this particular oxygen isotope change?

 

Fri, 08/15/2008 - 23:36

Jesse Burrows

Sections from the cores were collected from a depth of 25-100cm.  However, depth should not be of great concern provided the ice can be verified to be true glacial ice rather than superimposed refreeze; in the field this was based on visual inspection.  The water molecule isotopes to be analyzed are stable, and thus do not degrade over time.  The purpose of keeping the samples cool is to limit any exchange which may happen with air in the sample bottles, or outside, such changes would vary the isotopic ratio and alter the results.