Tectonic setting of gulf of aqaba
- 1. Tectonic setting of gulf of aqaba By: mohammed elsayed
- 3. Introduction • The gulf is east of the Sinai Peninsula and west of the Arabian Peninsula. • Latitude: 27° 56' 59.99" N • Longitude: 34° 35' 59.99" E • It reaches a maximum depth of 1,850 m in its central area. • the gulf is one of the world's premier sites for diving. • The area is especially rich in coral and other marine biodiversity .
- 4. • the Red Sea is well known as a place where the most extensive of the Earth's structural features. the rift system bifurcates, with the west branch of the V occupied by the Gulf of Suez, the eastern by the Gulf of aqaba. • The Gulf of Elat occupies the southern segment of the Dead Sea rift. This rift was formed in the Cenozoic by breakup of the once continuous Arabian—African platform. • Extending from the Red Sea via the Gulf of aqaba 600 km north to the Zagros-Taurus Mountains of Turkey, the transform-fault zone is known as the Gulf of Elat-Dead Sea Rift.
- 5. • about 105 km of left-lateral displacement has occurred on the Gulf of aqaba-Dead Sea rift .
- 6. • Movement took place in two stages, In the first stage, 65 km of left slip occurred possibly during the Miocene or somewhat earlier. • Over the lands which now border the southern Gulf of aqaba, especially on the eastern side, evaporites and other marine sediments of Miocene age accumulated. • Uplift of lands adjacent to the rift zone could have created as much as a kilometer of relief which was subsequently eroded nearly to base level, exposing large areas of Precambrian basement rock.
- 7. • Along the eastern side at the southern Gulf, the Miocene evaporites and other marine sediments survived the erosion. • The final stage of rifting, involving 40 to 50 km of left-lateral movement, took place 4 to 5 million years ago, shaping the present Gulf of aqaba.
- 8. • At that time the present deep basins formed as three in-echelon rhomb-shaped grabens (pull apart basins) formed by the strike-slip faulting.
- 9. • The Gulf with its deeper water, contains more than 2,000 to 3,000m of sediment infill, 5,000m of sediment infill in its northern and southern ends. • Relatively narrow marginal blocks and very steep slopes prevail on the eastern side of the Gulf, whereas relatively wide marginal blocks underlie the gentler slopes of the Western side. • Strike-slip movement on the rift is still active as shown by geologic, geomorphic and seismic studies.
- 10. Seismic activity of the Gulf of Aqaba region • The Gulf of Aqaba region has been affected by some 12 historical earthquakes within the last 10 decades with average recurrence periods 70–90, 167–200, and 333–500 years for M≥6.0, 6.5, and 7.0, respectively. At least, the largest four of these have occurred very close to the gulf or within it. • The epicentral distribution of the instrumental seismicity data indicates that all regional faults of the gulf area are active in the present. Most of the activity of the study period was concentrated within the area bound by latitudes 28.2°–29.8° and longitudes 34.4°–35.2°. This implies that the regional strike-slip and normal faults of the northern two basins Aqaba–Haqel and Nuwabie were the most active during this period. Their activity is at least twice that of the normal faults.
- 11. • The November 22, 1995, Aqaba earthquake demonstrated that this region is an active seismic area characterized by several strong earthquakes occurring at relatively short recurrence intervals. • On 22 November 1995 the largest earthquake iinstrumentally recordedin the area, with magnitude Mw 7.3, occurred in the Gulf of Aqaba. The main rupturecorresponding to the strike- slip mechanism is located within the gulf of Aqaba, which forms the marine extension of the Levantine fault, also known as the Dead Sea fault. • The earthquake swarms increase the hazard potential 24% in the northern part of the Gulf, while it has increased to 53% and 46% in the central and southern part of the Gulf, respectively.
- 12. thank you