Submitted by Anonymous on Sat, 12/13/2008 - 17:04
Forums
Ancient Buried Ice in Antarctica

Ms. Hams,

How many years per centimeter (average) are recorded in the ice core samples you pull out ?

Also, what time zone are you in ?

Chris Rizzo

Sat, 12/13/2008 - 18:46

Jacquelyn Hams

Typically, most ice-core studies include some type of age assessment vs depth, as you suggest.  But, the ice in Beacon Valley is different from typical ice cored in Antarctica.  Rather than having a simple progression of age with depth (as would be the case for horizontally layered ice), the ice in Beacon Valley is deformed, and most likely sheared in places.  This means that a simple chronology with depth is not possible.  The researchers are interested in archiving gasses from various geologic epics (snap shots, if you will), rather than colleting continuous core with a nice age progression with depth.
New Zealand time  - UTC +12
Jacquelyn Hams
Los Angeles Valley College 

Tue, 05/12/2009 - 15:30

Newkirk Family…

Given that you have a deformed ice layering, how do you determine that the ice in the area is many millions of years old?

Tue, 05/12/2009 - 21:48

La Vergne Rosow

Jackie,
What do you actually see when you look at one of those samples?
Is there anything that is interesting to the naked eye or do you need a microscope to see what is so exciting?
La Vergne

Thu, 05/28/2009 - 12:07

Jacquelyn Hams

 La Vergne
I sent you an email at school, but I will answer here as well.
As far as the ice cores go, Dave is looking for clear clean ice with well defined bubbles.  The presence of bubbles indicates that the atmospheric gases are present and the gases will be dated at a laboratory.
In other research areas in Antarctica, Dave and his graduate students have discovered fossils of plants and insects indicating that Antarctica was once a warmer tundra climate.
Jacquelyn Hams
Los Angeles Valley College 

Thu, 05/28/2009 - 12:11

Jacquelyn Hams

To the Newkirk Family:
The researchers base the chronology of the ice on the minimum ages of the overlying ash fall deposits. Also, previous studies have demonstrated that the ages of the glacier increase from the headwall as the glacier moves down valley.
Jacquelyn Hams
Los Angeles Valley College