Melchior Grab

Last Name

Grab

First Name

Melchior

ORCID

0000-0002-8293-4872

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Publications 1 - 10 of 47

High-resolution helicopter-borne ground penetrating radar survey to determine glacier base topography and the outlook of a proglacial lake
Church, Gregory James; Bauder, Andreas; Grab, Melchior; et al. (2018)
2018 17th International Conference on Ground Penetrating Radar (GPR)
Fault hydromechanical characterization and CO2-saturated water injection at the CS-D experiment (Mont Terri Rock Laboratory)
Wenning, Quinn; Rinaldi, Antonio Pio; Zappone, Alba; et al. (2020)
EGUsphere
CO2 Sequestration: Studying Caprock And Fault Sealing Integrity, The CS-D Experiment in Mont Terri
Zappone, Alba; Rinaldi, Antonio Pio; Grab, Melchior; et al. (2018)
Ice volume estimation in the Swiss Alps from helicopter-borne GPR and glaciological modeling
Grab, Melchior; Langhammer, Lisbeth; Bauder, Andreas; et al. (2018)
Abstract Volume 16th Swiss Geoscience Meeting, Bern 30th November - 1st December 2018, A Habitable Planet
Active seismic monitoring of Co2-saturated brine injection into a fault (CS-D experiment in the Mont Terri Rock Laboratory)
Grab, Melchior; Zappone, Alba; Rinaldi, Antonio Pio; et al. (2020)
EGUsphere
Geophysical instrumentation for monitoring CO2-brine injected into the main fault in Mont Terri
Grab, Melchior; Obermann, Anne; Rinaldi, Antonio Pio; et al. (2018)
Abstract Volume: 16th Swiss Geoscience Meeting
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps
Hellmann, Sebastian; Kerch, Johanna; Weikusat, Ilka; et al. (2021)
The Cryosphere
Crystal orientation fabric (COF) analysis provides information about the c-axis orientation of ice grains and the associated anisotropy and microstructural information about deformation and recrystallisation processes within the glacier. This information can be used to introduce modules that fully describe the microstructural anisotropy or at least direction-dependent enhancement factors for glacier modelling. The COF was studied at an ice core that was obtained from the temperate Rhonegletscher, located in the central Swiss Alps. Seven samples, extracted at depths between 2 and 79 m, were analysed with an automatic fabric analyser. The COF analysis revealed conspicuous four-maxima patterns of the c-axis orientations at all depths. Additional data, such as microstructural images, produced during the ice sample preparation process, were considered to interpret these patterns. Furthermore, repeated high-precision global navigation satellite system (GNSS) surveying allowed the local glacier flow direction to be determined. The relative movements of the individual surveying points indicated longitudinal compressive stresses parallel to the glacier flow. Finally, numerical modelling of the ice flow permitted estimation of the local stress distribution. An integrated analysis of all the data sets provided indications and suggestions for the development of the four-maxima patterns. The centroid of the four-maxima patterns of the individual core samples and the coinciding maximum eigenvector approximately align with the compressive stress directions obtained from numerical modelling with an exception for the deepest sample. The clustering of the c axes in four maxima surrounding the predominant compressive stress direction is most likely the result of a fast migration recrystallisation. This interpretation is supported by air bubble analysis of large-area scanning macroscope (LASM) images. Our results indicate that COF studies, which have so far predominantly been performed on cold ice samples from the polar regions, can also provide valuable insights into the stress and strain rate distribution within temperate glaciers.
Comparison of seismic velocities derived from crystal orientation fabrics and ultrasonic measurements on an ice core
Hellmann, Sebastian; Kerch, Johanna; Grab, Melchior; et al. (2020)
EGUsphere
Seismic velocity structure of a fossilized Icelandic geothermal system: A combined laboratory and field study
Grab, Melchior; Zürcher, Benjamin; Maurer, Hansruedi; et al. (2015)
Geothermics
Seismic velocity structure of a fossilized Icelandic geothermal system - a combined laboratory and field study
Grab, Melchior; Maurer, H.-R.; Greenhalgh, S.A (2015)

Publications 1 - 10 of 47

Melchior Grab

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