Oceanographic characteristics of the Granada coast
Discover the unique oceanographic characteristics of the Tropical Coast of Granada, from the influence of the Alboran Sea to the diversity of its underwater fauna and flora. In this section, we will explore in detail the highlights of his oceanography.
THE ALBORAN SEA
The Alboran Sea, located on the Tropical Coast of Granada, is in a unique position between the Atlantic and the Mediterranean, which gives it significant oceanographic importance. Its connection with the Atlantic through the Strait of Gibraltar (Illustration 1) triggers a complex system of currents that influence its hydrography.
These currents generate anticyclonic gyres, as shown in Illustration 2, which cause turbulence and mixing of waters. This interaction between Atlantic and Mediterranean waters creates the "Almería-Oran" front, an area of great biological diversity along its path. It is important to note that this mixing of waters results in a relative scarcity of nutrients compared to Atlantic waters.
However, the circulation of water in middle layers and the topography of the seabed generate deep water outcrops, as illustrated in Illustration 5 with the "Estepona outcrop". These outcrops, although they may vary in intensity due to meteorological conditions, are consistent and give rise to areas of high primary productivity. This makes the Alboran Sea one of the most fertile regions of the Mediterranean, providing a suitable habitat for the reproduction and growth of a wide variety of marine species.
Illustration 1. Basic circulation scheme between the Atlantic and Mediterranean water masses (Hernández‐Molina et al., 2002).
Illustration 2. Main currents in the Ibero-Moroccan region. Blue arrows: surface currents, predominance of Atlantic waters towards the Mediterranean and anticyclonic gyre in the Alboran Sea. Green arrows: Mediterranean waters leaving towards the Atlantic. (Modified from Gofas and García Raso, 2004).
Geomorphological features of the Alboran Sea
From a physiographic perspective, the Alboran Sea is divided into three large units, separated by a threshold where Alboran Island is located. These sub-basins are limited by the Iberian and Maghreb continental margins, whose emerged facades are marked by mountain ranges. The Western sub-basin stands out for its abyssal plain and the Gibraltar Channel. Seamounts such as the Djibouti Bank, composed of Avempace, Djibouti and El Idrisi mountains, display rich biodiversity and intriguing geological phenomena, such as detachment scars and sedimentary deposits. The morphology of these mountains, their proximity to the coast and the presence of cold water corals make them of great interest for scientific research. The group of mountains borders the Alborán Channel and the Adra Ridge, which contributes to the transport of sediments towards the Strait of Gibraltar. (Illustration 3).
The presence of these seamounts significantly influences the hydrodynamics and sediment distribution in the region. Furthermore, the morphology and structure of these mountains are the subject of detailed studies due to their importance for marine biodiversity and their potential as habitats for vulnerable ecosystems. Mounts Avempace, Djibouti and El Idrisi display unique geological and morphological features, such as serpentine ridges, central depressions and detachment scars, which make them of great scientific interest. Studies on sedimentary dynamics and biodiversity associated with these seamounts are essential to better understand the geological and biological processes in the Alboran Sea. (Illustration 4).
Illustration 3. Geomorphological characteristics of the Alboran Sea (modified from Vázquez, 2001). The numbers indicate the position of the elements: 1. Ceuta Canyon. 2. Xauen Bank. 3. Monte Vizconde de Eza. 4. Avempace or Algarrobo bench. 5. Bank of Djibouti. 6. Bank of El Edrisi. 7. Alborán Island and platform. 8. Banco de Chella or Seco de los Olivos. 9. Almería Canyon. 10. Bank of Avenzoar or El Sabinal. 11. Provençaux Bank. 12. Yusuf-Habibas Escarpment. Drawing: Serge Gofas; bathymetry according to Laughton et al., 1975.
Illustration Illustration 4. Toponymy in the Alborán Basin based on bathymetric synthesis (modified from Martínez-García et al., 2009). The bathymetric irregularity stands out on the northern slope of the Alborán Channel, while the southern slope shows a smoother morphology, suggesting sedimentary predominance. The southern façade of the Alborán Ridge is characterized by its rectilinear shape and sediment collapses, creating a lobed morphology.
DRY OLIVE TREES
El Seco de los Olivos, also known as Banco de Chella, is located at 36º31'N and 02º51'W, 14 miles southeast of Adra. This underwater elevation, surrounded by volcanic peaks, experiences strong currents that generate upwellings, fostering an extraordinary diversity of fauna and flora. The area is crucial for the conservation of species and habitats, documented by organizations such as Oceana and Alnitak, as it is home to corals, gorgonians and cetaceans such as the bottlenose dolphin and the pilot whale, some species being sighted for the first time on the Almeria coast, highlighting their high ecological value.
TIDES
In the Mediterranean Sea, the practical absence of tides is striking, although they are actually very weak since the small size of the Mediterranean basin does not favor the creation of larger tides and because the tides of the Gulf of Cádiz and the North Atlantic barely penetrate into the Mediterranean Sea and lose energy as they advance. And in many cases, meteorological conditions (atmospheric pressure and wind) exert a greater influence on sea level variations than the tidal range itself. Depending on the winds, in some areas sea advances of more than 10 have been experienced. m above its natural level of spring tides. In any case, and despite everything mentioned, it is worth noting that the highest tides in the western Mediterranean occur in the Alboran Sea.
