On the nature, interpretation, and application of electromagnetic reflections in cold ice
The investigation of glaciers and ice sheets by means of ice penetrating radar has become one of the most commonly used geophysical techniques in glaciology.This doctoral thesis contributes new approaches and results to the analysis of electromagnetic reflections originating within cold ice bodies.M...
Main Author: | |
---|---|
Other Authors: | , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
Universität Bremen
2003
|
Subjects: | |
Online Access: | https://media.suub.uni-bremen.de/handle/elib/2073 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000011332 |
id |
ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/2073 |
---|---|
record_format |
openpolar |
spelling |
ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/2073 2023-05-15T13:42:30+02:00 On the nature, interpretation, and application of electromagnetic reflections in cold ice Zur Natur, Interpretation und Anwendung elektromagnetischer Reflexionen in kaltem Eis Eisen, Olaf Miller, Heinrich Villinger, Heinrich 2003-03-14 application/pdf https://media.suub.uni-bremen.de/handle/elib/2073 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000011332 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/2073 urn:nbn:de:gbv:46-diss000011332 info:eu-repo/semantics/openAccess radar res emr ice sheet Antarctica internal reflections internal layers numerical modelling ice core eiskern dielectric properties physical properties 31 ddc:31 Dissertation doctoralThesis 2003 ftsubbremen 2022-11-09T07:09:44Z The investigation of glaciers and ice sheets by means of ice penetrating radar has become one of the most commonly used geophysical techniques in glaciology.This doctoral thesis contributes new approaches and results to the analysis of electromagnetic reflections originating within cold ice bodies.Main subject is the direct comparison of synthetic radargrams with radar survey data and the explanation of results thereof, especially in view of climatic interpretation of ice core records.In addition, new evaluations of survey techniques and data analyses are presented.Focusing on the region surrounding the EPICA ice core deep drilling location in Dronning Maud Land, Antarctica, different numerical forward modeling techniques are used. Physical in-situ properties are taken from three shallow ice cores for which profiles of the complex dielectric constant are available, radar reference traces are determined from surface-based radar surveys.Application of combined ice core and radar analyses focus on internal reflection horizons.The successful forward modeling allows numerical sensitivity studies with altered dielectric ice core data. Findings confirm earlier assumptions that changes in permittivity are responsible for observed reflection horizons in the upper part of the ice sheet.Although variations in conductivity are negligible for causing reflections, strong correlations of permittivity and conductivity signals indicate a mutual influence, and validate the isochronous character of reflection horizons.Based on this property, the error involved in the dating of reflection horizons and synchronization of ice cores is evaluated for the ice sheet in Dronning Maud Land and additionally for the cold alpine saddle Colle Gnifetti (Monte Rosa, Valaisian Alps).The results are promising as the errors determined in both studies are only relatively larger than the initial uncertainty related to ice core dating. Doctoral or Postdoctoral Thesis Antarc* Antarctica Dronning Maud Land EPICA ice core Ice Sheet Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Dronning Maud Land Monte Rosa ENVELOPE(162.850,162.850,-70.917,-70.917) |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
radar res emr ice sheet Antarctica internal reflections internal layers numerical modelling ice core eiskern dielectric properties physical properties 31 ddc:31 |
spellingShingle |
radar res emr ice sheet Antarctica internal reflections internal layers numerical modelling ice core eiskern dielectric properties physical properties 31 ddc:31 Eisen, Olaf On the nature, interpretation, and application of electromagnetic reflections in cold ice |
topic_facet |
radar res emr ice sheet Antarctica internal reflections internal layers numerical modelling ice core eiskern dielectric properties physical properties 31 ddc:31 |
description |
The investigation of glaciers and ice sheets by means of ice penetrating radar has become one of the most commonly used geophysical techniques in glaciology.This doctoral thesis contributes new approaches and results to the analysis of electromagnetic reflections originating within cold ice bodies.Main subject is the direct comparison of synthetic radargrams with radar survey data and the explanation of results thereof, especially in view of climatic interpretation of ice core records.In addition, new evaluations of survey techniques and data analyses are presented.Focusing on the region surrounding the EPICA ice core deep drilling location in Dronning Maud Land, Antarctica, different numerical forward modeling techniques are used. Physical in-situ properties are taken from three shallow ice cores for which profiles of the complex dielectric constant are available, radar reference traces are determined from surface-based radar surveys.Application of combined ice core and radar analyses focus on internal reflection horizons.The successful forward modeling allows numerical sensitivity studies with altered dielectric ice core data. Findings confirm earlier assumptions that changes in permittivity are responsible for observed reflection horizons in the upper part of the ice sheet.Although variations in conductivity are negligible for causing reflections, strong correlations of permittivity and conductivity signals indicate a mutual influence, and validate the isochronous character of reflection horizons.Based on this property, the error involved in the dating of reflection horizons and synchronization of ice cores is evaluated for the ice sheet in Dronning Maud Land and additionally for the cold alpine saddle Colle Gnifetti (Monte Rosa, Valaisian Alps).The results are promising as the errors determined in both studies are only relatively larger than the initial uncertainty related to ice core dating. |
author2 |
Miller, Heinrich Villinger, Heinrich |
format |
Doctoral or Postdoctoral Thesis |
author |
Eisen, Olaf |
author_facet |
Eisen, Olaf |
author_sort |
Eisen, Olaf |
title |
On the nature, interpretation, and application of electromagnetic reflections in cold ice |
title_short |
On the nature, interpretation, and application of electromagnetic reflections in cold ice |
title_full |
On the nature, interpretation, and application of electromagnetic reflections in cold ice |
title_fullStr |
On the nature, interpretation, and application of electromagnetic reflections in cold ice |
title_full_unstemmed |
On the nature, interpretation, and application of electromagnetic reflections in cold ice |
title_sort |
on the nature, interpretation, and application of electromagnetic reflections in cold ice |
publisher |
Universität Bremen |
publishDate |
2003 |
url |
https://media.suub.uni-bremen.de/handle/elib/2073 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000011332 |
long_lat |
ENVELOPE(162.850,162.850,-70.917,-70.917) |
geographic |
Dronning Maud Land Monte Rosa |
geographic_facet |
Dronning Maud Land Monte Rosa |
genre |
Antarc* Antarctica Dronning Maud Land EPICA ice core Ice Sheet |
genre_facet |
Antarc* Antarctica Dronning Maud Land EPICA ice core Ice Sheet |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/2073 urn:nbn:de:gbv:46-diss000011332 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766168679019446272 |