The Gravity Filed and Crustal Structure of the Southern end of the Ethiopian Rift System
| dc.contributor.advisor | Alemu, Abera (PhD) | |
| dc.contributor.author | Lakew, Alemayehu | |
| dc.date.accessioned | 2018-06-18T06:02:47Z | |
| dc.date.accessioned | 2023-11-09T11:25:18Z | |
| dc.date.available | 2018-06-18T06:02:47Z | |
| dc.date.available | 2023-11-09T11:25:18Z | |
| dc.date.issued | 1993-07 | |
| dc.description.abstract | The Bouguer anomaly map of the rift zone south of the southern end of the Main Ethiopian rift between Lat. 4° OO'N .;; 7° OO'N and Long. 36° 00 I E - 39° 45 ' E is presented. The computed Bouguer anomaly map shows a complex pattern of positive and negative Bouguer gravity anomalies. A positive Bouguer gravity anomaly of -165 mGal occurs over the floor of the Abaya-Chamo rift and is flanked by negative anomalies that reside on its shoulders. The anomaly pattern associated with the Chew Bahir rift is completely different from the other regions. The floor has a negative gravity anomaly of magnitude -135 mGal and is flanked by positive gravity anomalies residing on its shoulders. This may be attributed to the swamp and volcano-Iacostrine nature of the rift floor. Further south in Kenya, the Bouguer anomaly map shows that there is a relative increase in magnitude of the regional gravity field with a complex pattern of alternating positive and negative anomalies which are generally oriented a NNW-SSE and E-W direction. Two profiles that run through the major tectonic systems (the Abaya-chamo rift and the Chew Bahir rift) of interest in the area were extracted from the Bouguer anomaly map. 2%-0 gravity models were constructed along these profiles. The results of the model calculations are that: Along Profile AA, the crust beneath the plateaus is 35 to 40 km thick. within the axis of the Abaya-Chamo rift the crust thins to 29 km. Along profile BB, the crust beneath the high lands in the vicinity of the Amaro horst is 35 to 40 km thick. Beneath the rift zone, i.e., the floor of the Chew Bahir rift and the flanking uplifted regions the crust thins to 27 km. The observed crustal thinning beneath_the rift zones along both profiles is thought to be caused by an upward progression of low density mantle material (anomalous mantle) that intrudes itself into the lower crust | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/1098 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Rift Structure in Southern Ethiopia | en_US |
| dc.title | The Gravity Filed and Crustal Structure of the Southern end of the Ethiopian Rift System | en_US |
| dc.type | Thesis | en_US |