surface water south for about four months at a velocity of , whereas in winter the flow is reversed resulting in the inflow of water from the Gulf of Aden into the Red Sea. The net value of the latter predominates, resulting in an overall drift to the north end of the Red Sea. Generally, the velocity of the tidal current is with a maximum of at the mouth of the al-Kharrar Lagoon. However, the range of the north-northeast current along the Saudi coast is . Wind regime The north part of the Red Sea is dominated by persistent north-west winds, with speeds ranging between and . The rest of the Red Sea and the Gulf of Aden are subjected to regular and seasonally reversible winds. The wind regime is characterized by seasonal and regional variations in speed and direction with average speed generally increasing northward. Wind is the driving force in the Red Sea to transport material as suspension or as bedload. Wind-induced currents play an important role in the Red Sea in resuspending bottom sediments and transferring materials from sites of dumping to sites of burial in quiescent environment of deposition. Wind-generated current measurement is therefore important in order to determine the sediment dispersal pattern and its role in the erosion and accretion of the coastal rock exposure and the submerged coral beds. Geology The Red Sea was formed by the Arabian peninsula being split from the Horn of Africa by movement of the Red Sea Rift. This split started in the Eocene and accelerated during the Oligocene. The sea is still widening (in 2005, following a three-week period of tectonic activity it had grown by 8m), and it is considered that it will become an ocean in time (as proposed in the model of John Tuzo Wilson). In 1949, a deep water survey reported anomalously hot brines in the central portion of the Red Sea. Later work in the 1960s confirmed the presence of hot, , saline brines and associated metalliferous muds. The hot solutions were emanating from an active subseafloor rift. Lake Asal in Djibouti is eligible as an experimental site to study the evolution of the deep hot brines of the Red Sea. By observing the strontium isotope composition of the Red Sea brines, it is possible to deduce how these salt waters found at the bottom of the Red Sea could have evolved in