Editing Gulf of Finland (section)

==Geography==
[[File:la2-demis-gulf-of-finland.png|thumb|Gulf of Finland|300px]]
[[File:Record sea ice in Gulf of Finland 2003.jpg|thumb|Satellite image showing the gulf entirely frozen over in January 2003]]
The Gulf of Finland has an area of {{convert|30000|km2|sqmi|abbr=on}}.<ref>[https://www.britannica.com/EBchecked/topic/207525/Gulf-of-Finland Gulf of Finland] Encyclopædia Britannica</ref> The length (from the [[Hanko Peninsula]] to Saint Petersburg) is {{convert|400|km|abbr=on}} and the width varies from {{convert|70|km|abbr= on}} near the entrance to {{convert|130|km|abbr= on}} on the meridian of [[Moshchny Island]]; in the [[Neva Bay]], it decreases to {{convert|12|km|abbr= on}}. The gulf is relatively shallow, with the depth decreasing from the entrance to the gulf to the continent. The sharpest change occurs near [[Narva-Jõesuu]], which is why this place is called the Narva wall. The average depth is {{convert|38|m|abbr= on}} with the maximum of {{convert|115|m|abbr= on}}. The depth of the Neva Bay is less than {{convert|6|m|0}}; therefore, in March 2019, a channel was dug at the bottom for safe navigation. Because of the large influx of fresh water from rivers, especially from the Neva River (two-thirds of the total runoff), the gulf water has very low salinity – between 0.2 and 0.3&nbsp;‰ at the surface and 0.3–0.5&nbsp;‰ near the bottom. The average water temperature is close to {{convert|0|C|F}} in winter; in summer, it is {{convert|15|-|17|C|F}} at the surface and {{convert|2|-|3|C|F}} at the bottom. Parts of the gulf can freeze from late November to late April; the freezing starts in the east and gradually proceeds to the west. Complete freezing usually occurs by late January, and it may not occur in mild winters.<ref>{{Cite book|url= https://books.google.com/books?id=ouOA81nGkGkC&pg=PA336|page= 336|title= Operational oceanography: the challenge for European co-operation : proceedings of the First International Conference on EuroGOOS, 7–11 October 1996, The Hague, The Netherlands, Volume 1996|date= 12 December 1997|publisher= Elsevier|isbn= 0-444-82892-3}}</ref>
Frequent strong western winds cause waves, surges of water and [[floods in Saint Petersburg|floods]].<ref name="SPb Entsiklopediya" /><ref name="Leningradskaya oblast">Darinskii, A. V. [https://books.google.com/books?id=dHJ2HAAACAAJ ''Leningrad Oblast'']. Lenizdat, 1975</ref>

The northern coast of the gulf is high and winding, with abundant small bays and [[skerry|skerries]], but only a few large bays ([[Vyborg]]) and peninsulas (Hanko and [[Porkkalanniemi]]). The coast is mostly sloping; there are abundant sandy dunes, with occasional pine trees.<ref name="SPb Entsiklopediya" /> The southern shores are smooth and shallow, but along the entire coast runs a limestone escarpment, the [[Baltic Klint]], with a height up to {{convert|55|m|abbr= on}}.<ref name=envir.ee>{{cite web|url= http://www.envir.ee/klint/eng/17.html|title= East Viru Klint|work= North Estonian Klint as a symbol of Estonian nature|publisher= Ministry of the Environment|access-date= 2009-10-06|archive-url= https://web.archive.org/web/20091112092743/http://www.envir.ee/klint/eng/17.html|archive-date= 12 November 2009|url-status= dead}}</ref><ref name="Geologicheskie pamyatniki">{{Cite book |author = Khazanovich K.| title = Geological Monuments of Leningrad Oblast |publisher = Lenizdat |year = 1982}}</ref> In the east, the gulf ends with Neva Bay; in the west it merges with the Baltic Sea.

The gulf contains numerous banks, skerries and islands. The largest include [[Kotlin Island]] with the city of [[Kronstadt]] (population 42,800), [[Beryozovye Islands]], Lisiy Island, [[Maly Vysotsky Island]] with the nearby city of [[Vysotsk]] (population 1706), [[Gogland]] (Suursaari), [[Moshchny Island|Moshtchny]] (Lavansaari), [[Bolshoy Tyuters]] (Tytärsaari), [[Sommers]], [[Naissaar]], [[Kimitoön (island)|Kimitoön]], [[Kökar]], [[Seskar]] (Seiskari), [[Pakri Islands]] and others.<ref name="Atlas_USSR">Atlas of the USSR. – M.: GUGK, 1984</ref>

Starting in 1700, Russia constructed nineteen [[artificial island]]s with fortresses in the gulf. They aimed to defend Russia from maritime attacks, especially in the context of the [[Great Northern War]] of 1700–1721. Such fortresses include [[Fort Alexander (Saint Petersburg)|Fort Alexander]], [[Krasnaya Gorka fort|Krasnaya Gorka]], [[Fort Ino|Ino]], Totleben and {{ill|Kronshlot|ru|Кроншлот}}.<ref>[http://www.fingulf.ru/fort/ Gulf of Finland – Forts]. Fingulf.ru. Retrieved on 2011-08-14.</ref>

The largest rivers flowing into the gulf are the [[Neva River|Neva]] (from the east), the [[Narva River|Narva]] (from the south), and the [[Kymi (river)|Kymi]] (from the north). [[Keila River|Keila]], [[Pirita River|Pirita]], [[Jägala River|Jägala]], [[Kunda River|Kunda]], [[Luga River|Luga]], Sista and Kovashi flow into the gulf from the south. From the north flow the [[Sestra River (Leningrad Oblast)|Sestra River]], [[Porvoonjoki|Porvoo]], [[Vantaa (river)|Vantaa]] and several other small rivers. The [[Saimaa Canal]] connects the gulf with the [[Saimaa]] lake.<ref name="Atlas_USSR"/>

===Extent===
The [[International Hydrographic Organization]] defines the western limit of the Gulf of Finland as a line running from [[Spithami]] (59°13'N), in Estonia, through the Estonian island of [[Osmussaar]] from SE to NW and on to the SW extremity of [[Hanko Peninsula]] (22°54'E) in Finland.<ref>{{cite web
|url= https://iho.int/uploads/user/pubs/standards/s-23/S-23_Ed3_1953_EN.pdf
|title= Limits of Oceans and Seas, 3rd edition
|year= 1953
|publisher= International Hydrographic Organization
|access-date= 28 December 2020
|archive-url= https://web.archive.org/web/20111008191433/http://www.iho.int/iho_pubs/standard/S-23/S-23_Ed3_1953_EN.pdf
|archive-date= 8 October 2011
}}</ref>