TITLE:
Evaluation of the Crustal Features of the Gulf of Aqaba Deduced from Geophysical Data
AUTHORS:
A. Z. Hamouda, S. El-Gharabawy
KEYWORDS:
Gulf of Aqaba, Bouguer Map, Bathymetry, Crustal Thickness, Moho Discontinuity, Tectonics Activity, Red Sea
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.4,
April
17,
2019
ABSTRACT: The Gulf of Aqaba is considered as an interesting rift system. Therefore, it is
important to understand the crustal features and thickness variation along the
Gulf; to be able to evaluate the effect of tectonic activities in shaping the Gulf.
The obtained data were used to estimate the reliable empirical relations between
the Bouguer anomalies (ΔgB) and crustal thickness (Hc) in the Gulf of
Aqaba. This equation was used to calculate the depth reliefs to the Moho
boundary. The output map of the Moho relief and the corresponding crustal
thickness were constructed for the Gulf of Aqaba. The depth from sea level
down to the Moho discontinuity in the Gulf of Aqaba varies between about
37 km in the northern deep and abruptly changes to about 28 km at the
southern area, Tiran Strait. Below the central part of the gulf, a Moho depth
of about 34 km is obtained. The Red Sea crust is thinner than that of the Dead
Sea rift; indicating the presence of a mantel upwelling that is related to the
spreading of the sea floor. The asymmetry of crustal thickness between the
eastern and western borders of the Gulf of Aqaba could be attributed to simultaneous
strike-slip motion. The relative displacement between the two
borders is observed clearly through the sea floor and Moho discontinuity. The
displacement is nearly equivalent to 0.18° (i.e. about 20.4 km) and is assumed
to be achieved in about 4.08 to 3.4 million years, according to the estimated
rate of the transform motion along the Gulf of Aqaba (Dead Sea transform)
that is about 0.5 to 0.6 cm/y.