Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy
Impurities control a variety of physical properties of polar ice. Their impact can be observed at all scales – from the microstructure (e.g., grain size and orientation) to the ice sheet flow behavior (e.g., borehole tilting and closure). Most impurities in ice form micrometer-sized inclusions. It h...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-11-1075-2017 https://tc.copernicus.org/articles/11/1075/2017/ |
id |
ftcopernicus:oai:publications.copernicus.org:tc55479 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:tc55479 2023-05-15T13:54:27+02:00 Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy Eichler, Jan Kleitz, Ina Bayer-Giraldi, Maddalena Jansen, Daniela Kipfstuhl, Sepp Shigeyama, Wataru Weikusat, Christian Weikusat, Ilka 2018-09-27 application/pdf https://doi.org/10.5194/tc-11-1075-2017 https://tc.copernicus.org/articles/11/1075/2017/ eng eng doi:10.5194/tc-11-1075-2017 https://tc.copernicus.org/articles/11/1075/2017/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-11-1075-2017 2020-07-20T16:23:44Z Impurities control a variety of physical properties of polar ice. Their impact can be observed at all scales – from the microstructure (e.g., grain size and orientation) to the ice sheet flow behavior (e.g., borehole tilting and closure). Most impurities in ice form micrometer-sized inclusions. It has been suggested that these µ inclusions control the grain size of polycrystalline ice by pinning of grain boundaries (Zener pinning), which should be reflected in their distribution with respect to the grain boundary network. We used an optical microscope to generate high-resolution large-scale maps (3 µm pix −1 , 8 × 2 cm 2 ) of the distribution of micro-inclusions in four polar ice samples: two from Antarctica (EDML, MIS 5.5) and two from Greenland (NEEM, Holocene). The in situ positions of more than 5000 µ inclusions have been determined. A Raman microscope was used to confirm the extrinsic nature of a sample proportion of the mapped inclusions. A superposition of the 2-D grain boundary network and µ-inclusion distributions shows no significant correlations between grain boundaries and µ inclusions. In particular, no signs of grain boundaries harvesting µ inclusions could be found and no evidence of µ inclusions inhibiting grain boundary migration by slow-mode pinning could be detected. Consequences for our understanding of the impurity effect on ice microstructure and rheology are discussed. Text Antarc* Antarctica Greenland Ice Sheet Copernicus Publications: E-Journals Greenland Tilting ENVELOPE(-54.065,-54.065,49.700,49.700) The Cryosphere 11 3 1075 1090 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Impurities control a variety of physical properties of polar ice. Their impact can be observed at all scales – from the microstructure (e.g., grain size and orientation) to the ice sheet flow behavior (e.g., borehole tilting and closure). Most impurities in ice form micrometer-sized inclusions. It has been suggested that these µ inclusions control the grain size of polycrystalline ice by pinning of grain boundaries (Zener pinning), which should be reflected in their distribution with respect to the grain boundary network. We used an optical microscope to generate high-resolution large-scale maps (3 µm pix −1 , 8 × 2 cm 2 ) of the distribution of micro-inclusions in four polar ice samples: two from Antarctica (EDML, MIS 5.5) and two from Greenland (NEEM, Holocene). The in situ positions of more than 5000 µ inclusions have been determined. A Raman microscope was used to confirm the extrinsic nature of a sample proportion of the mapped inclusions. A superposition of the 2-D grain boundary network and µ-inclusion distributions shows no significant correlations between grain boundaries and µ inclusions. In particular, no signs of grain boundaries harvesting µ inclusions could be found and no evidence of µ inclusions inhibiting grain boundary migration by slow-mode pinning could be detected. Consequences for our understanding of the impurity effect on ice microstructure and rheology are discussed. |
format |
Text |
author |
Eichler, Jan Kleitz, Ina Bayer-Giraldi, Maddalena Jansen, Daniela Kipfstuhl, Sepp Shigeyama, Wataru Weikusat, Christian Weikusat, Ilka |
spellingShingle |
Eichler, Jan Kleitz, Ina Bayer-Giraldi, Maddalena Jansen, Daniela Kipfstuhl, Sepp Shigeyama, Wataru Weikusat, Christian Weikusat, Ilka Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy |
author_facet |
Eichler, Jan Kleitz, Ina Bayer-Giraldi, Maddalena Jansen, Daniela Kipfstuhl, Sepp Shigeyama, Wataru Weikusat, Christian Weikusat, Ilka |
author_sort |
Eichler, Jan |
title |
Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy |
title_short |
Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy |
title_full |
Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy |
title_fullStr |
Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy |
title_full_unstemmed |
Location and distribution of micro-inclusions in the EDML and NEEM ice cores using optical microscopy and in situ Raman spectroscopy |
title_sort |
location and distribution of micro-inclusions in the edml and neem ice cores using optical microscopy and in situ raman spectroscopy |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-11-1075-2017 https://tc.copernicus.org/articles/11/1075/2017/ |
long_lat |
ENVELOPE(-54.065,-54.065,49.700,49.700) |
geographic |
Greenland Tilting |
geographic_facet |
Greenland Tilting |
genre |
Antarc* Antarctica Greenland Ice Sheet |
genre_facet |
Antarc* Antarctica Greenland Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-11-1075-2017 https://tc.copernicus.org/articles/11/1075/2017/ |
op_doi |
https://doi.org/10.5194/tc-11-1075-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
3 |
container_start_page |
1075 |
op_container_end_page |
1090 |
_version_ |
1766260325790777344 |