Jump to content

Strait of Sicily: Difference between revisions

Coordinates: 37°12′N 11°12′E / 37.20°N 11.20°E / 37.20; 11.20
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
added new content. Ask permission to rewrite stub. References do not numerate well.
Line 37: Line 37:


The island of [[Pantelleria]] lies in the middle of the strait.
The island of [[Pantelleria]] lies in the middle of the strait.

[[File:Strait of Sicily map.png|thumb|Location of the Strait of Sicily on map.<ref>{{Citation|last=NormanEinstein|title=English: Map showing the location of the Strait of Sicily, between Sicily, Italy in Europe and Tunisia in Africa.|date=2009-02-06|url=https://commons.wikimedia.org/wiki/File:Strait_of_Sicily_map.png|access-date=2021-05-13}}</ref>]]The '''Strait of Sicily''' is located between, at the eastern side [[Tunisia]] and the Malta Bank and on the northern side [[Sicily]], [[Italy]]. Within the Central [[Mediterranean Sea|Mediterranean sea]] it is one of the topographically complex regions. With a length of 600 km it connects the Eastern and Western Mediterranean basins. The strait is delimited by two systems; at the eastern side it is connected with the [[Ionian Sea]], south of the Malta Bank with a sill of 560 m deep, and, on the western side, two passages of 430 m and 365 m deep connect the strait with the Western Mediterranean basin. In the central region the strait is around 50 km till 100 km wide and 700 m till 900 m deep, but some parts consist of trenches of even 1800 m deep. <ref name=":0">{{Cite journal|last=Astraldi|first=M.|last2=Gasparini|first2=G. P.|last3=Gervasio|first3=L.|last4=Salusti|first4=E.|date=2001-12-01|title=Dense Water Dynamics along the Strait of Sicily (Mediterranean Sea)|url=https://journals.ametsoc.org/view/journals/phoc/31/12/1520-0485_2001_031_3457_dwdats_2.0.co_2.xml|journal=Journal of Physical Oceanography|language=EN|volume=31|issue=12|pages=3457–3475|doi=10.1175/1520-0485(2001)0312.0.CO;2|issn=0022-3670}}</ref>

=== Flows ===
At the surface and in the upper 200 m the strait consists of an eastward flow provided by the Modified Atlantic Water (MAW). Underneath this eastward flow, the Levantine Intermediate Water (LIW) flows in westward direction.  Just above the bottom of the Strait a relative small flow has been observed. This vein follows the same route as LIW but consist of different characteristics.<ref>{{Cite journal|last=Astraldi|first=M.|last2=Gasparini|first2=G. P.|last3=Moretti|first3=M.|last4=Sansone|first4=E.|last5=Sparnocchia|first5=S.|year=1996|title=The characteristics of the water masses and the water transport in the Sicily Channel at long time scales.|journal=Dynamics of Mediterranean Straits and Channels|location=Bulletin de l'Institut Océanographique, Monaco|volume=CIESM Science Series 2}}</ref> The water flow is named 'transitional Eastern Mediterranean Deep Water' (tEMDW) <ref>{{Cite journal|last=Sparnocchia|first=S|last2=Gasparini|first2=G.P|last3=Astraldi|first3=M|last4=Borghini|first4=M|last5=Pistek|first5=P|date=1999-04-XX|title=Dynamics and mixing of the Eastern Mediterranean outflow in the Tyrrhenian basin|url=http://dx.doi.org/10.1016/s0924-7963(98)00088-8|journal=Journal of Marine Systems|volume=20|issue=1-4|pages=301–317|doi=10.1016/s0924-7963(98)00088-8|issn=0924-7963}}</ref> and contains fresher, colder and denser (''σ<sub>θ</sub>'' ∼ 29.10) water then the LIW. In the [[Ionian Sea]] it fills the transitional layer between the Easter Mediterranean Deep Water and the LIW. This dense water exits the strait at a dept of 300 m at the sill and sinks down, because of its higher density then the LIW, till 1800 m when reaching the [[Tyrrhenian Sea]] flowing along the Sicilian slope. This sharp sinking down of the dense water flow is a topic of interest among Oceanographers. A second topic of interest regarding this little tEMDW flow is that it crosses the midline of the strait, more precisely the Malta sill. When the dense water flow reaches the western sill, it flows along the Tunisian coast instead of the Sicilian shelf. The water mass flows at a shallow depth of 300 m, while beneath the LIW, the tEMDW flows westward. Further downstream, the LIW has lower velocities and the dense water flow returns to the [[Geostrophic current|geostrophic]] position located naturally along the Sicilian coast. Here the dense water sinks into the deeper ocean sea, around 1500-1850m. This inversion of the interface slope is possible because the [[buoyancy]] and [[Coriolis]] forces are ballancing eachother in a so called 'geostrophic balance' which is possible because of the flow velocities of both LIW and EMDW.

The tEMDW shows little variations in height, width and path and is thus geometrically quite stable.<ref name=":0" />

<references />

=== Dynamics ===
The Central Mediterranean can be characterized by looking at differences in spatial and temporal scale. Three scales are common to use among oceanographers.

The first being the [[mesoscale]] with a horizontal scale around ten kilometers and periods of days till a maximum of ten days. The sea can be influenced within the mesoscale by [[wind stress]], [[topography]] and by internal dynamical processes. Boundery currents and jets can be created by these processes which can evolve into [[Vortex|vortices]] and filament patterns that can interact with large scale flows.<ref>{{Citation|last=Robinson|first=A.R.|title=Data Assimilation In Models|date=2001|url=http://dx.doi.org/10.1006/rwos.2001.0404|work=Encyclopedia of Ocean Sciences|pages=623–634|publisher=Elsevier|isbn=978-0-12-227430-5|access-date=2021-05-13|last2=Lermusiaux|first2=P.F.J.}}</ref> <ref>{{Cite journal|last=Lermusiaux|first=P.F.J.|date=1999-07-XX|title=Estimation and study of mesoscale variability in the strait of Sicily|url=http://dx.doi.org/10.1016/s0377-0265(99)00008-1|journal=Dynamics of Atmospheres and Oceans|volume=29|issue=2-4|pages=255–303|doi=10.1016/s0377-0265(99)00008-1|issn=0377-0265}}</ref>

Secondly, the large Mediterranean Basin scale which includes the [[thermohaline circulation]]. The thermohaline circulation in the Strait of Sicily is anti-[[Estuary|estuarine]] and is driven by at one site, the fresh waters entering from the [[Strait of Gibraltar|Gibraltar Strait]] and on the other side, the negative fresh water budget from the [[Mediterranean Basin]]. <ref name=":1">{{Cite web|last=Sorgente|first=R.|last2=Olita|first2=A.|last3=Oddo|first3=P.|last4=Fazioli|first4=L.|last5=Ribotti|first5=A.|date=2011-05-24|title=Numerical simulation and decomposition of kinetic energies in the Central Mediterranean Sea: insight on mesoscale circulation and energy conversion|url=http://dx.doi.org/10.5194/osd-8-1161-2011|access-date=2021-05-14|website=dx.doi.org}}</ref> Also the westward LIW in the intermediate layer and less saltier eastward [[Atlantic Ocean|Atlantic]] water on top are considered in this scale.

The last common used scale is the sub-basin scale with scales of 200 km till 300 km. This scale represents two dense water veins; the Atlantic Tunisian Current (ATC)<ref>{{Cite journal|last=Sammari|first=C|last2=Millot|first2=C|last3=Taupier-Letage|first3=I|last4=Stefani|first4=A|last5=Brahim|first5=M|date=1999-10-XX|title=Hydrological characteristics in the Tunisia–Sardinia–Sicily area during spring 1995|url=http://dx.doi.org/10.1016/s0967-0637(99)00026-6|journal=Deep Sea Research Part I: Oceanographic Research Papers|volume=46|issue=10|pages=1671–1703|doi=10.1016/s0967-0637(99)00026-6|issn=0967-0637}}</ref> which flows along the African coast and the Atlantic Ionian Stream (AIS)<ref>{{Cite journal|last=Robinson|first=A.R.|last2=Sellschopp|first2=J.|last3=Warn-Varnas|first3=A.|last4=Leslie|first4=W.G.|last5=Lozano|first5=C.J.|last6=Haley|first6=P.J.|last7=Anderson|first7=L.A.|last8=Lermusiaux|first8=P.F.J.|date=1999-04-XX|title=The Atlantic Ionian Stream|url=http://dx.doi.org/10.1016/s0924-7963(98)00079-7|journal=Journal of Marine Systems|volume=20|issue=1-4|pages=129–156|doi=10.1016/s0924-7963(98)00079-7|issn=0924-7963}}</ref> along the Sicilian coast. The AIS flows mainly eastward which can create [[upwelling]] on the Adventure Bank (AB) and the southern Sicilian coast. Upwelling is found to be the most intense during summer when the AIS is also relatively stronger then in other seasons. Due to the upwelling these coasts are of great interests of fishery. The ATC shows a specific path in winter while the route is less clearly-marked during summer. <ref>{{Cite book|last=Verfasser|first=Sorgente, R.|url=http://worldcat.org/oclc/1188462670|title=Seasonal variability in the Central Mediterranean Sea circulation|oclc=1188462670}}</ref><ref name=":1" /><ref>{{Cite journal|last=BERANGER|first=K|date=2004-05|title=The dynamics of the Sicily Strait: a comprehensive study from observations and models|url=http://dx.doi.org/10.1016/s0967-0645(04)00027-x|journal=Deep Sea Research Part II: Topical Studies in Oceanography|doi=10.1016/s0967-0645(04)00027-x|issn=0967-0645}}</ref>

The outflow of dense-water-masses characteristics of the Strait of Sicily are not stable but have been found to change interannually.<ref>{{Cite journal|last=Gasparini|first=G.P.|last2=Ortona|first2=A.|last3=Budillon|first3=G.|last4=Astraldi|first4=M.|last5=Sansone|first5=E.|date=2005-06|title=The effect of the Eastern Mediterranean Transient on the hydrographic characteristics in the Strait of Sicily and in the Tyrrhenian Sea|url=http://dx.doi.org/10.1016/j.dsr.2005.01.001|journal=Deep Sea Research Part I: Oceanographic Research Papers|volume=52|issue=6|pages=915–935|doi=10.1016/j.dsr.2005.01.001|issn=0967-0637}}</ref> Also the thermohaline circulation showed changes in structure and [[Stratification (water)|stratification]]. These changes were caused by deep water formed in the [[Aegean Sea]] which replaced the water formed in the [[Adriatic Sea|Adriatic]] during the 1990s. This dense water caused enhanced salinity and temperatures for a few years creating the Medirranean Transient (EMT).<ref>{{Cite journal|last=Roether|first=Wolfgang|last2=Klein|first2=Birgit|last3=Manca|first3=Beniamino Bruno|last4=Theocharis|first4=Alexander|last5=Kioroglou|first5=Sotiris|date=2007-09|title=Transient Eastern Mediterranean deep waters in response to the massive dense-water output of the Aegean Sea in the 1990s|url=http://dx.doi.org/10.1016/j.pocean.2007.03.001|journal=Progress in Oceanography|volume=74|issue=4|pages=540–571|doi=10.1016/j.pocean.2007.03.001|issn=0079-6611}}</ref> <ref>{{Cite journal|last=Theocharis|first=A.|last2=Klein|first2=B.|last3=Nittis|first3=K.|last4=Roether|first4=W.|date=2002-06|title=Evolution and status of the Eastern Mediterranean Transient (1997–1999)|url=http://dx.doi.org/10.1016/s0924-7963(02)00054-4|journal=Journal of Marine Systems|volume=33-34|pages=91–116|doi=10.1016/s0924-7963(02)00054-4|issn=0924-7963}}</ref>

The Biomodal Oscillating System (BiOS)<ref>{{Cite journal|last=Gačić|first=M.|last2=Borzelli|first2=G. L. Eusebi|last3=Civitarese|first3=G.|last4=Cardin|first4=V.|last5=Yari|first5=S.|date=2010-05|title=Can internal processes sustain reversals of the ocean upper circulation? The Ionian Sea example|url=http://dx.doi.org/10.1029/2010gl043216|journal=Geophysical Research Letters|volume=37|issue=9|pages=n/a–n/a|doi=10.1029/2010gl043216|issn=0094-8276}}</ref> connects the upper layer of the Ionian sea circulation with the thermohaline of the Adriatic deep water and the salt distribution over the Eastern Mediterranean. The upper-layer Ionian circulation reversed from [[Anticyclonic rotation|anticyclonic]] to [[Cyclonic rotation|cyclonic]] and back to anticyclonic on decadal time scales.<ref>{{Cite web|last=Bonanno|first=A.|last2=Placenti|first2=F.|last3=Basilone|first3=G.|last4=Mifsud|first4=R.|last5=Genovese|first5=S.|last6=Patti|first6=B.|last7=Di Bitetto|first7=M.|last8=Aronica|first8=S.|last9=Barra|first9=M.|date=2014-03-13|title=Variability of water mass properties in the Strait of Sicily in summer period of 1998–2013|url=http://dx.doi.org/10.5194/osd-11-811-2014|access-date=2021-05-14|website=dx.doi.org}}</ref>

<references />

=== Levatine intermediate water circulation ===
Through the strait of Sicilie passes the Levantine Intermediate Water (LIW). The LIW is a westward flowing water mass in the intermediate layers (from 200 m till 400 m) formed in the [[Levantine Sea|lavantine basin]], the most eastern part of the Mediterranean sea and ending in the [[strait of Gibraltar]] and the [[Atlantic Ocean]]. The LIW is characterized by high [[salinity]] and temperature. This high salinity concentrations is one of the important factors for the formation of the deep water in the Southern Adriatic and the [[Gulf of Lion|Gulf of Lions]]. <ref>{{Citation|last=Nittis|first=K.|title=Intermediate Water Formation in the Levantine Sea: The Response to Interannual Variability of Atmospheric Forcing|date=1999|url=http://dx.doi.org/10.1007/978-94-011-4796-5_31|work=The Eastern Mediterranean as a Laboratory Basin for the Assessment of Contrasting Ecosystems|pages=441–446|place=Dordrecht|publisher=Springer Netherlands|isbn=978-0-7923-5586-1|access-date=2021-05-13|last2=Lascaratos|first2=A.}}</ref>

=== Migrants ===
[[Pantelleria]] is an Italian island located in the Strait of Sicily around 64 km from Tunesia. Nowadays the island is one of the destinations migrants, mostly from Tunesia, try to reach. Sometimes even more then 200 people in only two days cross the Strait in little boats. <ref>{{Cite web|title=Migranti, a Pantelleria riprendono gli sbarchi dalla Tunisia: arrivati più di 200|url=https://trapani.gds.it/articoli/cronaca/2020/10/12/migranti-a-pantelleria-riprendono-gli-sbarchi-dalla-tunisia-arrivati-piu-di-200-268f5f3d-e479-4ad3-91fd-f45a80303631/|access-date=2021-05-13|website=Giornale di Sicilia|language=it}}</ref>

=== Winds ===
The winds that are found above the Strait of Sicily are the two Mediterranean winds: [[Sirocco]], bringing dry and warm air from the Sourth East and [[Mistral (wind)|Mistral]], bringing cold air from the North West.

=== Biology ===
The Strait of Sicily is rich in biodiversity due to its different water currents. Also its geographical  position between the Eastern and Western Mediterranean contributes to the high ecological importance of the Strait. Warm temperature and tropical species from the [[Levantine Sea|Lavantin basin]] cross the Strait. The vast variety in species cannot only be found near the surface and coasts but also the deep water contains communities of vulnerable species as the [[Scleractinia]], [[Black coral|Antipatharia’s]], [[Gorgonia|gorgonians]] and [[Precious coral|red corals]].<ref>{{Cite journal|last=Di Lorenzo|first=Manfredi|last2=Sinerchia|first2=Matteo|last3=Colloca|first3=Francesco|date=2017-10-11|title=The North sector of the Strait of Sicily: a priority area for conservation in the Mediterranean Sea|url=http://dx.doi.org/10.1007/s10750-017-3389-7|journal=Hydrobiologia|volume=821|issue=1|pages=235–253|doi=10.1007/s10750-017-3389-7|issn=0018-8158}}</ref>

The habitat of one of the corals in Strait, the [[Precious coral|Corallium rubrum]], family of the  [[Coralliidae]] ([[Anthozoa]], [[Alcyonacea|Gorgonacea]]) is between a few meters depth till 120 m.<ref>{{Cite journal|last=Taviani|first=Marco|last2=Freiwald|first2=Andre|last3=Beuck|first3=Lydia|last4=Angeletti|first4=Lorenzo|last5=Remia|first5=Alessandro|last6=Vertino|first6=Agostina|last7=Dimech|first7=Mark|last8=Schembri|first8=Patrick Joseph|title=The deepest known occurrence of the precious red coral Corallium Rubrum (L. 1758) in the Mediterranean Sea.|url=https://www.researchgate.net/publication/230866824_The_deepest_known_occurrence_of_the_precious_red_coral_Corallium_Rubrum_L_1758_in_the_Mediterranean_Sea|journal=Conference: Proceedings of the International Workshop on Red Coral Science, Management, and Trade: Lessons from the Mediterranean}}</ref>. It’s bright red calcific axis has been used for jewelry in the antique days till now.<ref>{{Cite journal|last=Cattaneo-Vietti|first=R.|last2=Cicogna|first2=F.|year=1993|title=Red Coral in the Mediterranean Sea: Art, History and Science.|journal=Ministero delle Risorse Agricole, Alimentari e Forestali|location=Rome|pages=263}}</ref><ref>{{Cite journal|last=Tsounis|first=Georgios|last2=Rossi|first2=Sergio|last3=Aranguren|first3=Maria|last4=Gili|first4=Josep-Maria|last5=Arntz|first5=Wolf|date=2006-01|title=Effects of spatial variability and colony size on the reproductive output and gonadal development cycle of the Mediterranean red coral (Corallium rubrum L.)|url=http://dx.doi.org/10.1007/s00227-005-0100-8|journal=Marine Biology|volume=148|issue=3|pages=513–527|doi=10.1007/s00227-005-0100-8|issn=0025-3162}}</ref> Although extinction of these corals is not the case yet because of high productivity in this ecosystem, a decline has been observed in the shallow waters.<ref>{{Cite journal|last=Tsounis|first=Georgios|last2=Rossi|first2=Sergio|last3=Gili|first3=Josep-Maria|last4=Arntz|first4=Wolf E.|date=2007-08-04|title=Red Coral Fishery at the Costa Brava (NW Mediterranean): Case Study of an Overharvested Precious Coral|url=http://dx.doi.org/10.1007/s10021-007-9072-5|journal=Ecosystems|volume=10|issue=6|pages=975–986|doi=10.1007/s10021-007-9072-5|issn=1432-9840}}</ref><ref>{{Cite journal|last=Santangelo|first=Giovanni|last2=Abbiati|first2=Marco|date=2001|title=Red coral: conservation and management of an over-exploited Mediterranean species|url=http://dx.doi.org/10.1002/aqc.451|journal=Aquatic Conservation: Marine and Freshwater Ecosystems|volume=11|issue=4|pages=253–259|doi=10.1002/aqc.451|issn=1052-7613}}</ref> <ref>{{Cite journal|last=Santangelo|first=G|last2=Carletti|first2=E|last3=Maggi|first3=E|last4=Bramanti|first4=L|date=2003|title=Reproduction and population sexual structure of the overexploited Mediterranean red coral Corallium rubrum|url=http://dx.doi.org/10.3354/meps248099|journal=Marine Ecology Progress Series|volume=248|pages=99–108|doi=10.3354/meps248099|issn=0171-8630}}</ref>

These corrals are part of an initiative of worldwide conservation. During the Conference of the Parties of CITES  number 14 (CoP14) two workshops were decided to be organized about the corals in the Pacific and Mediterranean. <ref>{{Cite journal|year=2009|title=Red Coral Science, Management and Trading: Lessons from the Mediterranean|journal=Ministero Affari Esteri, Ministero dell’Ambiente e della Tutela del Territorio e del Mare, Università degli Studi di Napoli “Parthenope”, International Workshop Napoli-Villa Doria D’Angri. 23-26 Settembre 2009|volume=Abstract|pages=49}}</ref><ref>{{Cite journal|last=IAPPCS|date=March 7, 2009|title=Report of the First Meeting in Hong Kong|journal=International Forum on Precious Coral|pages=50}}</ref>

Among the species that are fished at high rates, are the family of the [[Cephalopod|Cephalopods]]. These [[Mollusca|molluscans]], especially the O. Vulgaris specie, are of interest both for industrial as for artisanal fisheries.

Due to the high biodiversity, productivity rates and importance of the different species for the ecosystem, the Mediterranean Sea and the Strait of Sicily are becoming of more interest for researchers during the recent years. <ref>{{Cite journal|last=Garofalo|first=Germana|last2=Ceriola|first2=Luca|last3=Gristina|first3=Michele|last4=Fiorentino|first4=Fabio|last5=Pace|first5=Roberta|date=2010-08-04|title=Nurseries, spawning grounds and recruitment of Octopus vulgaris in the Strait of Sicily, central Mediterranean Sea|url=http://dx.doi.org/10.1093/icesjms/fsq101|journal=ICES Journal of Marine Science|volume=67|issue=7|pages=1363–1371|doi=10.1093/icesjms/fsq101|issn=1095-9289}}</ref>

Also regarding the current [[climate change]], information can be gained by researching the changes in biodiversity in the Strait of Sicily.<ref>{{Cite journal|last=Di Lorenzo|first=Manfredi|last2=Sinerchia|first2=Matteo|last3=Colloca|first3=Francesco|date=2017-10-11|title=The North sector of the Strait of Sicily: a priority area for conservation in the Mediterranean Sea|url=http://dx.doi.org/10.1007/s10750-017-3389-7|journal=Hydrobiologia|volume=821|issue=1|pages=235–253|doi=10.1007/s10750-017-3389-7|issn=0018-8158}}</ref>

=== Vulcanic activity ===
[[File:Sicily Tectonic Plates.png|thumb|224x224px|Tectonic Plates underneath the Strait of Sicily.<ref>{{Citation|last=FieldsetJ|title=English: Map of tectonic plates of Sicily, modified from File:Tectonic_plates_(empty).svg|date=2017-11-09|url=https://commons.wikimedia.org/wiki/File:Sicily_Tectonic_Plates.png|access-date=2021-05-13}}</ref>]]
Due to the natural position of the Strait of Sicily, above the conjunction of the [[Eurasian Plate|Eurasian]] and [[African Plate|African]] tectonic plate, volcanic activity occurs in the strait.

The volcanic activity is mainly focused on the islands [[Pantelleria]] and [[Linosa]]. A climax in volcanic activity was found in the [[Pleistocene]]. Although minor submarine eruptions can still be found, mostly located on the seafloor along the North west- and South east regional faults.<ref>{{Cite journal|last=Calanchi|first=N.|last2=Colantoni|first2=P.|last3=Rossi|first3=P.L.|last4=Saitta|first4=M.|last5=Serri|first5=G.|date=1989-05-XX|title=The Strait of Sicily continental rift systems: Physiography and petrochemistry of the submarine volcanic centres|url=http://dx.doi.org/10.1016/0025-3227(89)90145-x|journal=Marine Geology|volume=87|issue=1|pages=55–83|doi=10.1016/0025-3227(89)90145-x|issn=0025-3227}}</ref>

During historical times some [[Seamount|seamounts]] did erupt while other seamounts have been covered by Pliocene-Quaternary sediments.

The submarine volcanoes are located in the Adventure Plateau, Graham and Nameless Banks. In 1831 a submarine volcano erupted on the Graham Bank at a dept of around 200 m. This eruption gave rise to the [[Graham Island (Mediterranean Sea)|Graham Island]] 65 m above sea level. Also in the year 1863 this volcano erupted where ass the youngest eruption in the region was in 1891 around 5km north of Pantelleria. At the south east of Graham Bank, at the Pinne Bank an emission was observed in 1941.<ref>{{Cite journal|last=Carapezza|first=M.|last2=Ferla|first2=P.|last3=Nuccio|first3=P. M.|last4=Valenza|first4=M.|year=1979|title=Caratteri petrologici e geochimici delle vulcaniti dell’Isola «Ferdinandea».|journal=Rend. Soc. Ital. Mineral. Petrol.|volume=35|pages=377-388}}</ref> <ref>{{Cite journal|last=Imbò|first=G.|year=1965|title=Catalogue of the active volcanoes of the world including solfatara fields.|journal=Italy. Intern. Assoc. Volcanology.|location=Rome|volume=Part XVIII|pages=72}}</ref> <ref>{{Cite web|title=Sicily Channel (Sicilian Channel; Strait of Sicily), Italy|url=https://www.mindat.org/loc-291596.html|access-date=2021-05-13|website=www.mindat.org}}</ref>


==See also==
==See also==

Revision as of 19:02, 15 May 2021

For waters separating Sicily from the rest of Italy, see Strait of Messina.
Strait of Sicily
Strait of Sicily is located in Europe
Strait of Sicily
Strait of Sicily
Map showing the location of the Strait of Sicily
Coordinates37°12′N 11°12′E / 37.20°N 11.20°E / 37.20; 11.20
Basin countriesItaly, Tunisia
Max. width145 kilometres (90 mi)
Max. depth316 meters (1,037 ft)

The Strait of Sicily (also known as Sicilian Strait, Sicilian Channel, Channel of Sicily, Sicilian Narrows and Pantelleria Channel; Italian: Canale di Sicilia or the Stretto di Sicilia; Sicilian: Canali di Sicilia or Strittu di Sicilia, Arabic: مضيق صقلية Maḍīq Ṣiqillīyah or مضيق الوطن القبلي Maḍīq al-Waṭan al-Qiblī) is the strait between Sicily and Tunisia.[1][2] The strait is about 145 kilometres (90 mi) wide and divides the Tyrrhenian Sea and the western Mediterranean Sea, from the eastern Mediterranean Sea. The maximum depth is 316 meters (1,037 ft).

Deep currents in the strait flow from east to west, and the current nearer the surface travels from west to east. This unusual water flow is of interest to oceanographers.[3]

There are regular ferries between Sicily and Tunis across the Strait of Sicily.

The island of Pantelleria lies in the middle of the strait.

Location of the Strait of Sicily on map.[4]

The Strait of Sicily is located between, at the eastern side Tunisia and the Malta Bank and on the northern side Sicily, Italy. Within the Central Mediterranean sea it is one of the topographically complex regions. With a length of 600 km it connects the Eastern and Western Mediterranean basins. The strait is delimited by two systems; at the eastern side it is connected with the Ionian Sea, south of the Malta Bank with a sill of 560 m deep, and, on the western side, two passages of 430 m and 365 m deep connect the strait with the Western Mediterranean basin. In the central region the strait is around 50 km till 100 km wide and 700 m till 900 m deep, but some parts consist of trenches of even 1800 m deep. [5]

Flows

At the surface and in the upper 200 m the strait consists of an eastward flow provided by the Modified Atlantic Water (MAW). Underneath this eastward flow, the Levantine Intermediate Water (LIW) flows in westward direction.  Just above the bottom of the Strait a relative small flow has been observed. This vein follows the same route as LIW but consist of different characteristics.[6] The water flow is named 'transitional Eastern Mediterranean Deep Water' (tEMDW) [7] and contains fresher, colder and denser (σθ ∼ 29.10) water then the LIW. In the Ionian Sea it fills the transitional layer between the Easter Mediterranean Deep Water and the LIW. This dense water exits the strait at a dept of 300 m at the sill and sinks down, because of its higher density then the LIW, till 1800 m when reaching the Tyrrhenian Sea flowing along the Sicilian slope. This sharp sinking down of the dense water flow is a topic of interest among Oceanographers. A second topic of interest regarding this little tEMDW flow is that it crosses the midline of the strait, more precisely the Malta sill. When the dense water flow reaches the western sill, it flows along the Tunisian coast instead of the Sicilian shelf. The water mass flows at a shallow depth of 300 m, while beneath the LIW, the tEMDW flows westward. Further downstream, the LIW has lower velocities and the dense water flow returns to the geostrophic position located naturally along the Sicilian coast. Here the dense water sinks into the deeper ocean sea, around 1500-1850m. This inversion of the interface slope is possible because the buoyancy and Coriolis forces are ballancing eachother in a so called 'geostrophic balance' which is possible because of the flow velocities of both LIW and EMDW.

The tEMDW shows little variations in height, width and path and is thus geometrically quite stable.[5]

  1. ^ Strait of Sicily, Britannica Atlas, Encyclopædia Britannica, Chicago (U.S.A.), 1989. Page 36, Geographic coordinates 37.20N 11.20E.
  2. ^ Scott C. Truver (1980), The Strait of Gibraltar and the Mediterranean, Springer, 1st edition.
  3. ^ Allan R. Robinson, Wayne G. Leslie, Alexander Theocharis, Alex Lascaratos. "Mediterranean Sea Circulation" (PDF). robinson.seas.harvard.edu.{{cite web}}: CS1 maint: multiple names: authors list (link)
  4. ^ NormanEinstein (2009-02-06), English: Map showing the location of the Strait of Sicily, between Sicily, Italy in Europe and Tunisia in Africa., retrieved 2021-05-13
  5. ^ a b Astraldi, M.; Gasparini, G. P.; Gervasio, L.; Salusti, E. (2001-12-01). "Dense Water Dynamics along the Strait of Sicily (Mediterranean Sea)". Journal of Physical Oceanography. 31 (12): 3457–3475. doi:10.1175/1520-0485(2001)0312.0.CO;2. ISSN 0022-3670.
  6. ^ Astraldi, M.; Gasparini, G. P.; Moretti, M.; Sansone, E.; Sparnocchia, S. (1996). "The characteristics of the water masses and the water transport in the Sicily Channel at long time scales". Dynamics of Mediterranean Straits and Channels. CIESM Science Series 2. Bulletin de l'Institut Océanographique, Monaco.
  7. ^ Sparnocchia, S; Gasparini, G.P; Astraldi, M; Borghini, M; Pistek, P (1999-04-XX). "Dynamics and mixing of the Eastern Mediterranean outflow in the Tyrrhenian basin". Journal of Marine Systems. 20 (1–4): 301–317. doi:10.1016/s0924-7963(98)00088-8. ISSN 0924-7963. {{cite journal}}: Check date values in: |date= (help)

Dynamics

The Central Mediterranean can be characterized by looking at differences in spatial and temporal scale. Three scales are common to use among oceanographers.

The first being the mesoscale with a horizontal scale around ten kilometers and periods of days till a maximum of ten days. The sea can be influenced within the mesoscale by wind stress, topography and by internal dynamical processes. Boundery currents and jets can be created by these processes which can evolve into vortices and filament patterns that can interact with large scale flows.[1] [2]

Secondly, the large Mediterranean Basin scale which includes the thermohaline circulation. The thermohaline circulation in the Strait of Sicily is anti-estuarine and is driven by at one site, the fresh waters entering from the Gibraltar Strait and on the other side, the negative fresh water budget from the Mediterranean Basin. [3] Also the westward LIW in the intermediate layer and less saltier eastward Atlantic water on top are considered in this scale.

The last common used scale is the sub-basin scale with scales of 200 km till 300 km. This scale represents two dense water veins; the Atlantic Tunisian Current (ATC)[4] which flows along the African coast and the Atlantic Ionian Stream (AIS)[5] along the Sicilian coast. The AIS flows mainly eastward which can create upwelling on the Adventure Bank (AB) and the southern Sicilian coast. Upwelling is found to be the most intense during summer when the AIS is also relatively stronger then in other seasons. Due to the upwelling these coasts are of great interests of fishery. The ATC shows a specific path in winter while the route is less clearly-marked during summer. [6][3][7]

The outflow of dense-water-masses characteristics of the Strait of Sicily are not stable but have been found to change interannually.[8] Also the thermohaline circulation showed changes in structure and stratification. These changes were caused by deep water formed in the Aegean Sea which replaced the water formed in the Adriatic during the 1990s. This dense water caused enhanced salinity and temperatures for a few years creating the Medirranean Transient (EMT).[9] [10]

The Biomodal Oscillating System (BiOS)[11] connects the upper layer of the Ionian sea circulation with the thermohaline of the Adriatic deep water and the salt distribution over the Eastern Mediterranean. The upper-layer Ionian circulation reversed from anticyclonic to cyclonic and back to anticyclonic on decadal time scales.[12]

  1. ^ Robinson, A.R.; Lermusiaux, P.F.J. (2001), "Data Assimilation In Models", Encyclopedia of Ocean Sciences, Elsevier, pp. 623–634, ISBN 978-0-12-227430-5, retrieved 2021-05-13
  2. ^ Lermusiaux, P.F.J. (1999-07-XX). "Estimation and study of mesoscale variability in the strait of Sicily". Dynamics of Atmospheres and Oceans. 29 (2–4): 255–303. doi:10.1016/s0377-0265(99)00008-1. ISSN 0377-0265. {{cite journal}}: Check date values in: |date= (help)
  3. ^ a b Sorgente, R.; Olita, A.; Oddo, P.; Fazioli, L.; Ribotti, A. (2011-05-24). "Numerical simulation and decomposition of kinetic energies in the Central Mediterranean Sea: insight on mesoscale circulation and energy conversion". dx.doi.org. Retrieved 2021-05-14.
  4. ^ Sammari, C; Millot, C; Taupier-Letage, I; Stefani, A; Brahim, M (1999-10-XX). "Hydrological characteristics in the Tunisia–Sardinia–Sicily area during spring 1995". Deep Sea Research Part I: Oceanographic Research Papers. 46 (10): 1671–1703. doi:10.1016/s0967-0637(99)00026-6. ISSN 0967-0637. {{cite journal}}: Check date values in: |date= (help)
  5. ^ Robinson, A.R.; Sellschopp, J.; Warn-Varnas, A.; Leslie, W.G.; Lozano, C.J.; Haley, P.J.; Anderson, L.A.; Lermusiaux, P.F.J. (1999-04-XX). "The Atlantic Ionian Stream". Journal of Marine Systems. 20 (1–4): 129–156. doi:10.1016/s0924-7963(98)00079-7. ISSN 0924-7963. {{cite journal}}: Check date values in: |date= (help)
  6. ^ Verfasser, Sorgente, R. Seasonal variability in the Central Mediterranean Sea circulation. OCLC 1188462670. {{cite book}}: |last= has generic name (help)CS1 maint: multiple names: authors list (link)
  7. ^ BERANGER, K (2004-05). "The dynamics of the Sicily Strait: a comprehensive study from observations and models". Deep Sea Research Part II: Topical Studies in Oceanography. doi:10.1016/s0967-0645(04)00027-x. ISSN 0967-0645. {{cite journal}}: Check date values in: |date= (help)
  8. ^ Gasparini, G.P.; Ortona, A.; Budillon, G.; Astraldi, M.; Sansone, E. (2005-06). "The effect of the Eastern Mediterranean Transient on the hydrographic characteristics in the Strait of Sicily and in the Tyrrhenian Sea". Deep Sea Research Part I: Oceanographic Research Papers. 52 (6): 915–935. doi:10.1016/j.dsr.2005.01.001. ISSN 0967-0637. {{cite journal}}: Check date values in: |date= (help)
  9. ^ Roether, Wolfgang; Klein, Birgit; Manca, Beniamino Bruno; Theocharis, Alexander; Kioroglou, Sotiris (2007-09). "Transient Eastern Mediterranean deep waters in response to the massive dense-water output of the Aegean Sea in the 1990s". Progress in Oceanography. 74 (4): 540–571. doi:10.1016/j.pocean.2007.03.001. ISSN 0079-6611. {{cite journal}}: Check date values in: |date= (help)
  10. ^ Theocharis, A.; Klein, B.; Nittis, K.; Roether, W. (2002-06). "Evolution and status of the Eastern Mediterranean Transient (1997–1999)". Journal of Marine Systems. 33–34: 91–116. doi:10.1016/s0924-7963(02)00054-4. ISSN 0924-7963. {{cite journal}}: Check date values in: |date= (help)
  11. ^ Gačić, M.; Borzelli, G. L. Eusebi; Civitarese, G.; Cardin, V.; Yari, S. (2010-05). "Can internal processes sustain reversals of the ocean upper circulation? The Ionian Sea example". Geophysical Research Letters. 37 (9): n/a–n/a. doi:10.1029/2010gl043216. ISSN 0094-8276. {{cite journal}}: Check date values in: |date= (help)
  12. ^ Bonanno, A.; Placenti, F.; Basilone, G.; Mifsud, R.; Genovese, S.; Patti, B.; Di Bitetto, M.; Aronica, S.; Barra, M. (2014-03-13). "Variability of water mass properties in the Strait of Sicily in summer period of 1998–2013". dx.doi.org. Retrieved 2021-05-14.

Levatine intermediate water circulation

Through the strait of Sicilie passes the Levantine Intermediate Water (LIW). The LIW is a westward flowing water mass in the intermediate layers (from 200 m till 400 m) formed in the lavantine basin, the most eastern part of the Mediterranean sea and ending in the strait of Gibraltar and the Atlantic Ocean. The LIW is characterized by high salinity and temperature. This high salinity concentrations is one of the important factors for the formation of the deep water in the Southern Adriatic and the Gulf of Lions. [1]

Migrants

Pantelleria is an Italian island located in the Strait of Sicily around 64 km from Tunesia. Nowadays the island is one of the destinations migrants, mostly from Tunesia, try to reach. Sometimes even more then 200 people in only two days cross the Strait in little boats. [2]

Winds

The winds that are found above the Strait of Sicily are the two Mediterranean winds: Sirocco, bringing dry and warm air from the Sourth East and Mistral, bringing cold air from the North West.

Biology

The Strait of Sicily is rich in biodiversity due to its different water currents. Also its geographical  position between the Eastern and Western Mediterranean contributes to the high ecological importance of the Strait. Warm temperature and tropical species from the Lavantin basin cross the Strait. The vast variety in species cannot only be found near the surface and coasts but also the deep water contains communities of vulnerable species as the Scleractinia, Antipatharia’s, gorgonians and red corals.[3]

The habitat of one of the corals in Strait, the Corallium rubrum, family of the  Coralliidae (Anthozoa, Gorgonacea) is between a few meters depth till 120 m.[4]. It’s bright red calcific axis has been used for jewelry in the antique days till now.[5][6] Although extinction of these corals is not the case yet because of high productivity in this ecosystem, a decline has been observed in the shallow waters.[7][8] [9]

These corrals are part of an initiative of worldwide conservation. During the Conference of the Parties of CITES  number 14 (CoP14) two workshops were decided to be organized about the corals in the Pacific and Mediterranean. [10][11]

Among the species that are fished at high rates, are the family of the Cephalopods. These molluscans, especially the O. Vulgaris specie, are of interest both for industrial as for artisanal fisheries.

Due to the high biodiversity, productivity rates and importance of the different species for the ecosystem, the Mediterranean Sea and the Strait of Sicily are becoming of more interest for researchers during the recent years. [12]

Also regarding the current climate change, information can be gained by researching the changes in biodiversity in the Strait of Sicily.[13]

Vulcanic activity

Tectonic Plates underneath the Strait of Sicily.[14]

Due to the natural position of the Strait of Sicily, above the conjunction of the Eurasian and African tectonic plate, volcanic activity occurs in the strait.

The volcanic activity is mainly focused on the islands Pantelleria and Linosa. A climax in volcanic activity was found in the Pleistocene. Although minor submarine eruptions can still be found, mostly located on the seafloor along the North west- and South east regional faults.[15]

During historical times some seamounts did erupt while other seamounts have been covered by Pliocene-Quaternary sediments.

The submarine volcanoes are located in the Adventure Plateau, Graham and Nameless Banks. In 1831 a submarine volcano erupted on the Graham Bank at a dept of around 200 m. This eruption gave rise to the Graham Island 65 m above sea level. Also in the year 1863 this volcano erupted where ass the youngest eruption in the region was in 1891 around 5km north of Pantelleria. At the south east of Graham Bank, at the Pinne Bank an emission was observed in 1941.[16] [17] [18]

See also

References

  1. ^ Nittis, K.; Lascaratos, A. (1999), "Intermediate Water Formation in the Levantine Sea: The Response to Interannual Variability of Atmospheric Forcing", The Eastern Mediterranean as a Laboratory Basin for the Assessment of Contrasting Ecosystems, Dordrecht: Springer Netherlands, pp. 441–446, ISBN 978-0-7923-5586-1, retrieved 2021-05-13
  2. ^ "Migranti, a Pantelleria riprendono gli sbarchi dalla Tunisia: arrivati più di 200". Giornale di Sicilia (in Italian). Retrieved 2021-05-13.
  3. ^ Di Lorenzo, Manfredi; Sinerchia, Matteo; Colloca, Francesco (2017-10-11). "The North sector of the Strait of Sicily: a priority area for conservation in the Mediterranean Sea". Hydrobiologia. 821 (1): 235–253. doi:10.1007/s10750-017-3389-7. ISSN 0018-8158.
  4. ^ Taviani, Marco; Freiwald, Andre; Beuck, Lydia; Angeletti, Lorenzo; Remia, Alessandro; Vertino, Agostina; Dimech, Mark; Schembri, Patrick Joseph. "The deepest known occurrence of the precious red coral Corallium Rubrum (L. 1758) in the Mediterranean Sea". Conference: Proceedings of the International Workshop on Red Coral Science, Management, and Trade: Lessons from the Mediterranean.
  5. ^ Cattaneo-Vietti, R.; Cicogna, F. (1993). "Red Coral in the Mediterranean Sea: Art, History and Science". Ministero delle Risorse Agricole, Alimentari e Forestali. Rome: 263.
  6. ^ Tsounis, Georgios; Rossi, Sergio; Aranguren, Maria; Gili, Josep-Maria; Arntz, Wolf (2006-01). "Effects of spatial variability and colony size on the reproductive output and gonadal development cycle of the Mediterranean red coral (Corallium rubrum L.)". Marine Biology. 148 (3): 513–527. doi:10.1007/s00227-005-0100-8. ISSN 0025-3162. {{cite journal}}: Check date values in: |date= (help)
  7. ^ Tsounis, Georgios; Rossi, Sergio; Gili, Josep-Maria; Arntz, Wolf E. (2007-08-04). "Red Coral Fishery at the Costa Brava (NW Mediterranean): Case Study of an Overharvested Precious Coral". Ecosystems. 10 (6): 975–986. doi:10.1007/s10021-007-9072-5. ISSN 1432-9840.
  8. ^ Santangelo, Giovanni; Abbiati, Marco (2001). "Red coral: conservation and management of an over-exploited Mediterranean species". Aquatic Conservation: Marine and Freshwater Ecosystems. 11 (4): 253–259. doi:10.1002/aqc.451. ISSN 1052-7613.
  9. ^ Santangelo, G; Carletti, E; Maggi, E; Bramanti, L (2003). "Reproduction and population sexual structure of the overexploited Mediterranean red coral Corallium rubrum". Marine Ecology Progress Series. 248: 99–108. doi:10.3354/meps248099. ISSN 0171-8630.
  10. ^ "Red Coral Science, Management and Trading: Lessons from the Mediterranean". Ministero Affari Esteri, Ministero dell’Ambiente e della Tutela del Territorio e del Mare, Università degli Studi di Napoli “Parthenope”, International Workshop Napoli-Villa Doria D’Angri. 23-26 Settembre 2009. Abstract: 49. 2009.
  11. ^ IAPPCS (March 7, 2009). "Report of the First Meeting in Hong Kong". International Forum on Precious Coral: 50.
  12. ^ Garofalo, Germana; Ceriola, Luca; Gristina, Michele; Fiorentino, Fabio; Pace, Roberta (2010-08-04). "Nurseries, spawning grounds and recruitment of Octopus vulgaris in the Strait of Sicily, central Mediterranean Sea". ICES Journal of Marine Science. 67 (7): 1363–1371. doi:10.1093/icesjms/fsq101. ISSN 1095-9289.
  13. ^ Di Lorenzo, Manfredi; Sinerchia, Matteo; Colloca, Francesco (2017-10-11). "The North sector of the Strait of Sicily: a priority area for conservation in the Mediterranean Sea". Hydrobiologia. 821 (1): 235–253. doi:10.1007/s10750-017-3389-7. ISSN 0018-8158.
  14. ^ FieldsetJ (2017-11-09), English: Map of tectonic plates of Sicily, modified from File:Tectonic_plates_(empty).svg, retrieved 2021-05-13
  15. ^ Calanchi, N.; Colantoni, P.; Rossi, P.L.; Saitta, M.; Serri, G. (1989-05-XX). "The Strait of Sicily continental rift systems: Physiography and petrochemistry of the submarine volcanic centres". Marine Geology. 87 (1): 55–83. doi:10.1016/0025-3227(89)90145-x. ISSN 0025-3227. {{cite journal}}: Check date values in: |date= (help)
  16. ^ Carapezza, M.; Ferla, P.; Nuccio, P. M.; Valenza, M. (1979). "Caratteri petrologici e geochimici delle vulcaniti dell'Isola «Ferdinandea»". Rend. Soc. Ital. Mineral. Petrol. 35: 377–388.
  17. ^ Imbò, G. (1965). "Catalogue of the active volcanoes of the world including solfatara fields". Italy. Intern. Assoc. Volcanology. Part XVIII. Rome: 72.
  18. ^ "Sicily Channel (Sicilian Channel; Strait of Sicily), Italy". www.mindat.org. Retrieved 2021-05-13.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Strait_of_Sicily&oldid=1023318276"