Air bubbles and clathrate hydrates in the transition zone of the NGRIP deep ice core

Abstract.Field studies of air bubble and clathrate inclusions in the NGRIP ice core reveal two stages of clathrate formation. In the transition zone translucent primary clathrates with rough surfaces and irregular shapes, formed from individual bubbles, split up and form smaller specimens. Deeper do...

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Bibliographic Details
Main Authors: Kipfstuhl, Sepp, Pauer, F., Kuhs, W. F., Shoji, H.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2001
Subjects:
Online Access:https://epic.awi.de/id/eprint/1658/
https://hdl.handle.net/10013/epic.12249
Description
Summary:Abstract.Field studies of air bubble and clathrate inclusions in the NGRIP ice core reveal two stages of clathrate formation. In the transition zone translucent primary clathrates with rough surfaces and irregular shapes, formed from individual bubbles, split up and form smaller specimens. Deeper down in the transition zone (~1100 m), clathrate metamorphosis sets in, giving rise to the formation of transparent secondary clathrates, with smooth and regular, often poly-hedral or faceted shapes. Rod-like crystals of great length (~2 mm) often show signs of separation into smaller units that fragment into smaller specimens. These findings imply that the simplified picture of one bubble forming one clathrate has to be modified.