Transition from continental rifting to oceanic spreading in the northern Red Sea area
- 1King Saud University, Saudi Arabia (k_sami11@yahoo.com) & (nalarifi@ksu.edu.sa)
- 2National Research Institute of Astronomy and Geophysics, Seismology Department, NRIAG, Helwan 11421, Egypt (k_sami11@yahoo.com)
- 3Novosibirsk State University, Novosibirsk, Russia, Pirogova 2, Novosibirsk 630090, Russia (ivan.science@gmail.com)
- 4Novosibirsk State University, Novosibirsk, Russia, Pirogova 2, Novosibirsk 630090, Russia (ivan.science@gmail.com)
- 5Institute of Volcanology and Seismology FEB RAS, Piip Boulevard, 9, 693006, Petropavlovsk-Kamchatsky, Russia (ivan.science@gmail.com)
- 6King Abdulaziz City of Science and Technology, Riyadh, Saudi Arabia (malajmi@kacst.edu.sa, aqadrouh@kacst.edu.sa).
Lithosphere extension, which plays an essential role in plate tectonics, occurs both in continents (as rift systems) and oceans (spreading along mid-oceanic ridges). The northern Red Sea area is a unique natural geodynamic laboratory, where the ongoing transition from continental rifting to oceanic spreading can be observed. Here, we analyze travel time data from a merged catalogue provided by the Egyptian and Saudi Arabian seismic networks to build a three-dimensional model of seismic velocities in the crust and uppermost mantle beneath the northern Red Sea and surroundings. The derived structures clearly reveal a high-velocity anomaly coinciding with the Red Sea basin and a narrow low-velocity anomaly centered along the rift axis. We interpret these structures as a transition of lithospheric extension from continental rifting to oceanic spreading. The transitional lithosphere is manifested by a dominantly positive seismic anomaly indicating the presence of a 50–70-km-thick and 200–300-km-wide cold lithosphere. Along the forming oceanic ridge axis, an elongated low-velocity anomaly marks a narrow localized nascent spreading zone that disrupts the transitional lithosphere. Along the eastern margins of the Red Sea, the lithosphere is disturbed by the lower-velocity anomalies coinciding with areas of basaltic magmatism.
How to cite: El Khrepy, S., Koulakov, I., Al-Arifi, N., S. Alajmi, M., and N. Qadrouh, A.: Transition from continental rifting to oceanic spreading in the northern Red Sea area, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4185, https://doi.org/10.5194/egusphere-egu21-4185, 2021.