Localization and analysis of calving-related seismicity at Kronebreen, Svalbard
The glacier calving process is poorly documented but closely related to glacier dynamics. Glaciers respond to many factors, such as air temperature or precipitation and can affect calving activity. Accessing calving rate data and mechanism can enhance understanding of the glacier behavior and may en...
| Main Author: | |
|---|---|
| Format: | Master Thesis |
| Language: | English |
| Published: |
2015
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/10852/45791 http://urn.nb.no/URN:NBN:no-50025 |
| Summary: | The glacier calving process is poorly documented but closely related to glacier dynamics. Glaciers respond to many factors, such as air temperature or precipitation and can affect calving activity. Accessing calving rate data and mechanism can enhance understanding of the glacier behavior and may enable estimating future response of the polar areas to the changing environment. This thesis is testing a possible tool for continuous calving monitoring. A non-permanent seismometer deployment was used to record seismic activity at Kronebreen, glacier in western Spitsbergen (Svalbard). Calving-related seismic events were separated from other activity based on the signal characteristics predefined from previous studies and localization of the signal. Three methods were used to obtain the location: frequency-wavenumber analysis (FK), spatial mapping by multi-array beamforming (SMAB) and phase picking. These methods were compared in order to choose the most appropriate one for future studies. More than 1300 calving-related icequakes were recorded and successfully localized. Temporal distribution of calving activity was affected by several factors: precipitation, temperature, tides and season variations. Terminus of the glacier retreated between May and September which was possible to observe through calving-related events locations as those retreated with time. SMAB was found to be the most accurate method and most appropriate for similar studies in the future. Array aperture, location and configuration can be improved to decrease uncertainty of the localization. The seismic processing can be automatized in order to apply this method for larger dataset and enable long-term calving monitoring. |
|---|