Gibraltar Strait

From unpolluted areas From moderately Hg-polluted areas From highly polluted areas Swordfish, Xiphius gladius Muscle NW Atlantic Peru Pacific W. Atlantic Gibraltar Strait... 

In Fig. 7, in three separated maps, all thrust (in red), strike-slip (in green), and extensional (in blue) focal mechanisms are shown these views help to study at larger scale the active tectonic styles. Thrust beach balls represent the compressive tectonic style and their distribution shows where the boundary between tectonic plates collides. This type of deformation occurs along a nearly continuous and narrow zone in Northern Africa, from Morocco to Northern Sicily, with two interruptions at the Gibraltar Strait (Fig. 6c) and south of Sardinia. Another continuous part of the tectonic boundary characterized by compressive features is along the eastern part of the Adriatic Sea, along Dinarides and Hellenides belts and partially around the Hellenic Trench. Other minor regions characterized by a compressive deformation are in the Northern Apeimines and around Cyprus Island. 

The largest evaporate basin formed in recent geological history is the Mediterranean basin. A closed, or almost closed, basin formed when mountain building blocked the Straits of Gibraltar some 6 million years ago. Before the Straits opened again, half a million years later, a layer of 1 kilometer of evaporates had accumulated on the basin floor. 

The modern Mediterranean Sea has a water volume of 3.7 x lo km. Net evaporation presently occurs at a rate of 3 3 x 10 km /y. If the Straits of Gibraltar were exposed today, the present-day Mediterranean Sea would dry up in about 1000 y. Assuming an average salinity of 37%o and a seasalt density of 2.165 g/cm, the Mediterranean would have had to been refilled and evaporated at least 15 times to accoimt for the volume of salt in the Messinian evaporites (1 x 10 km ). The evaporites on the margins of the Mediterranean Sea tend to be thinner than the deposits in the middle and deepest parts of the basin, which are up to 1600 m in thickness. In some limited areas on the eastern side of the basin, thicknesses up to 3500 m have been observed ... 

As the story goes, the Phoenicians set sail westward through the Straits of Gibraltar and discovered what were then known as the tin islands somewhere in the Adantic Ocean. Because this was a rich find of an essential metal, they kept the source a secret. It is now believed that they actually found tin on the coast of England in a section we now know as Cornwall, which still produces tin ore. 

Pandolfi M, Gonzalez-Catanedo Y, Alastuey A, de la Rosa JD, Mantilla E, Querol X, Pey J, Amato F, Moreno T (2011) Source apportionment of PM10 and PM2.5 at multiple sites in the strait of Gibraltar by PMF impact of shipping emissions. Env Sci Poll Res 18 260-269... 

Morocco, on the north coast of Africa directly across the Strait of Gibraltar from Spain, is the closest country to Western Europe where marijuana is extensively grown and used by the inhabitants. It is a poor country, with the per capita income less than 200 per year. Morocco obtained its independence from Spain and France only in 1956. Marijuana is grown in quantity by the mountain-dwelling "unaccultur-ated" Berber tribes in the Rif Mountains and is sold in the partially Westernized coastal plains. 

Figure 4.13. Elements of the global water balance with the role of the ocean taken into account. Notations wA0L, wA0P, wA0I, wA0P precipitation Hpo, Hop Straits of Gibraltar Rp, Rj, RL rivers EPA, E1A, EPA, ELA evaporation Apl, A1P the Antarctic Current MP1 the Cape Igolny Current CPj the East-Australian Current fiPL Bering Strait 1LP Arctic ice DPP Drake Passage IP Antarctic ice NPI Indonesian seas Slf> Sfl straits.

The concentration of dissolved nutrients in the deep waters of the Eastern Mediterranean is much lower than those in other oceans of the world, and when these are mixed into the surface waters they support very low primary productivity. The basic reason for this ultra-oligotrophic status is that the Mediterranean has an anti-estuarine (reverse thermohaline) circulation in which nutrient-depleted surface waters flow into the western basin at the Straits of Gibraltar and then on into the eastern basin at the Straits of Sicily. The deeper counter current consists of Levantine Intermediate Water (LIW) which contains a significant amount of dissolved nutrients. 

The Mediterranean is situated at the northern boundary of the desert climatic belt. As a result there is a significant net loss of water from the basin. The Mediterranean in general, and the Eastern Mediterranean in particular, has a large excess of evaporation over precipitation. This results in an anti-estuarine (reverse thermohaline) circulation. Low salinity water flows into the Mediterranean basin from the eastern North Atlantic. This water flows in within the upper water layers at the Straits of Gibraltar. The salinity of this surface water is 36.15. The surface water moves to the west generally following the coast of North Africa. It then flows through the Straits of Sicily. However, the flow of... 

VergnaudGrazzini C., Caralp M., Faugeres J.-C., Gonthier E., Grousset F., Puiol C. and Saliege J.-F. (1989) Mediterranean outflow through the Strait of Gibraltar since 18000 years BP. Oceanol. Acta 12, 305-324. 

Christie, R.R. Bordley, R.F. Boucher, C. Calvert, C.E. Petit, G. Willis, P. (1989). The Establishment of a Survey Network for Use on the Cross Channel Project. First International Workshop on Geodesy for the Europe-Africa fixed link feasibility studies in the Strait of Gibraltar. Madrid. 

And for a Voyage to the Straits of Gibraltar. From a Fifteenth Century MS. Edited by James Gairdner, Esq. with a Glossary by E. Delmar Morgan, Esq. (1889. Issued for... 

Stoeppler, M. Bernhard, F. Backhaus and . Schulte, Mercury in marine organisms from the Western Italian coast, the Strait of Gibraltar and the North Sea, Scl.Tot.Envlronm., 13 209 (1979). Ahmed, P. Valenta and H. W. Niimberg, Voltammetrlc determination of mercury levels in tuna fish, Microchlm.Acta, 171 (1981). Stoeppler and K. Brandt, Comparative studies on trace metal levels in marine biota. II. Trace metal in Krill, Krillproducts and fish from the Antarctic Scotia Sea, Z.Lebensm.Unters.Forsch., 169 95 (1979). 

Planning completed, or at least terminated, the assault and assault support convoys, late in October and early in November, sailed from Hampton Roads, Va., and England s Mersey ports. The first convoy from England entered the Strait of Gibraltar on 5 November 1942. 

---