University of Twente Student Theses
Characterization of active and inactive hydrothermal alterations in the Ethiopian Rift Valley system
Seevaratnam, Bardhipan (2013) Characterization of active and inactive hydrothermal alterations in the Ethiopian Rift Valley system.
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| Abstract: | The characterization of active and inactive hydrothermal alteration provides information for geologists and stakeholders the recency of the system, thereby providing further knowledge about the geological phase a given hydrothermal alteration is in. Having this information is also crucial in making informed decisions for mining exploration, since it will illustrate the erosional processes of these two systems based on their exposed alteration zones. The characterization of active and inactive hydrothermal alteration systems was studied using band ratios and corrected night-time TIR images from ASTER. Selected band ratios from literature were used to characterize the active and inactive alteration. The night-time thermal images were also used along with STcorr application to remove the artifacts, for better discriminate between active and inactive hydrothermal zones. Band ratios on both inactive and active zones were inconclusive from both the dry and wet seasons. Band ratio values were high from using the Level 2 AST_07XT data product. The sensitivity issue was also studied in the results of the statistical tests and the results had shown statistical differences were found for areas that were visually similar in the box plots. This was due to the outliers in the data. Working with night-time imagery had also illustrated sensitivity to polynomial fits. The polynomial fit, which is user defined, results in different interpretation of active zones, while inactive zones, the polynomial fitting did not affect the discrimination. The study illustrate insight into the scale of temperature gradients, which are not localized to hydrothermal zones only, but actually have larger imprints that also influence other areas (active and inactive) in the Ethiopian Rift Valley system. Keywords: Active Hydrothermal Alteration, Inactive Hydrothermal Alteration, ASTER, Ethiopian Rift Valley, Geothermal, Berecha, Tendaho |
| Item Type: | Essay (Master) |
| Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
| Subject: | 38 earth sciences |
| Programme: | Geoinformation Science and Earth Observation MSc (75014) |
| Link to this item: | https://purl.utwente.nl/essays/93732 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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