Integrated Geophysical Investigations to Characterize the Shashamane-Aje 2016 Ground Fissures, Main Ethiopian Rift
| dc.contributor.advisor | Haile, Tigistu (Professer) | |
| dc.contributor.author | Samuel, Mekdes | |
| dc.date.accessioned | 2019-05-01T06:13:59Z | |
| dc.date.accessioned | 2023-11-04T12:22:42Z | |
| dc.date.available | 2019-05-01T06:13:59Z | |
| dc.date.available | 2023-11-04T12:22:42Z | |
| dc.date.issued | 5/3/2017 | |
| dc.description.abstract | In this thesis work two integrated geophysical methods, namely magnetic and electrical resistivity (resistivity sounding and axial Dipole-Dipole profiling) have been carried out over the large size ground fissure that occurred following the heavy inundation in the summer of 2016 at Oine Chafo Umbure, Shashamane area which is located within the Central part of the Main Ethiopian Rift (CMER). The electrical data were then analyzed and interpreted with appropriate software and presented in the form of apparent resistivity pseudodepth and geoelectric section as well and 2D inverse model sections for the Dipole-Dipole survey. The pseudodepth section shows that the shallow zones (approximately up to depth of 50m) have high resistivity and the extensive substratum part have low resistivity values. The geoelectric section constructed for the same profile shows that the subsurface consists of 4 geoelectric horizons. The 2D inverse model section of the two Dipole-Dipole profiles show that there are three subsurface horizons up to the depth of 18m with some layer discontinuities. The top and bottom layers have high resistivity while the intermediate horizon has moderate to low resistivity. The magnetic data were corrected and the resulting anomaly plots are presented in terms of residual plots and analytic signal maps. The residual magnetic profile values were also modeled to obtain possible subsurface stratification of the area. Interpretation of magnetic data and the 2D magnetic model section both show that there are a number of discontinuities transecting the area around the fissures. The combined geophysical survey result shows that the low resistivity second layer is the weakest layer on the subsurface that resulted in sliding of the top layers and formation of the fissures due to excessive clogging with the water. It was no, however, possible to correlate the various discontinuities mapped with the survey to the deeper Rift structures because of the limitation of the depth of investigation of the electrical surveys. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/18176 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Integrated Geophysical | en_US |
| dc.subject | Investigations | en_US |
| dc.subject | Characterize the Shashamane | en_US |
| dc.subject | Ground Fissures | en_US |
| dc.subject | Geology | en_US |
| dc.title | Integrated Geophysical Investigations to Characterize the Shashamane-Aje 2016 Ground Fissures, Main Ethiopian Rift | en_US |
| dc.type | Thesis | en_US |