Editing Geography of Finland (section)

===Relief and hydrography===
{{See also|List of islands of Finland}}
[[File:Svedjehamnin näkötorni 04.06.2016.jpg|thumb|An aerial view of the [[Kvarken Archipelago]]]]
About one third of Finland lies below 100 m, and about two thirds lies under 200 m.<ref name="Natenterrang" /> Finland can be divided into three topographical areas; the coastal landscapes, the [[Finnish Lakeland|interior lake plateau]] also known as Finnish lake district and [[Upland Finland]].<ref name="Natenterrang">{{cite web |url=https://www.ne.se/uppslagsverk/encyklopedi/l%C3%A5ng/finland?i_h_word=%25C3%25B6sterland |title=Finland: Terrängformer och berggrund |last1=Behrens |first1=Sven |last2=Lundqvist|first2=Thomas|author-link2=Thomas Lundqvist (geologist) |website=[[Nationalencyklopedin]] |publisher=Cydonia Development |access-date=November 30, 2017 |language=sv}}</ref> The coastal landscapes are made up mostly of plains below 20 m. These plains tilt gently towards the sea so that where its irregularities surpasses sea-level groups of islands like the [[Norra Kvarken|Kvarken Archipelago]] or the [[Åland|Åland Islands]] are found.<ref name="Natenterrang" /> Åland is connected to the Finnish mainland by a shallow submarine plateau that does not exceed 20 m in depth.<ref name="UppslagsFiUniv">{{cite web |url=http://uppslagsverket.fi/sv/sok/view-103684-Aaland |title=Åland |last=Lindberg |first=Johan  |date=May 26, 2016 |website=[[Uppslagsverket Finland]] |access-date=November 30, 2017 |language=sv}}</ref> Next to the [[Gulf of Bothnia]] the landscape of Finland is extremely flat with height differences no larger than 50 m.<ref name="Rudberg">{{cite book |last=Rudberg |first=Sten |author-link=Sten Rudberg |date=1960 |title=Geography of Norden |chapter=Geology and Morphology |pages=27–40|editor-last=Somme|editor-first=Axel|editor-link=Axel Sømme }}</ref> This region called the [[Ostrobothnian Plain]] extends inland about 100&nbsp;km and constitute the largest plain in the [[Nordic countries]].<ref name="Rudberg" />

The interior lake plateau is dominated by undulating hilly terrain with valley to top height differences of 100 or less and occasionally up to 200 m.<ref name="Natenterrang" /><ref name="Rudberg" /> Only the area around the lakes [[Pielinen]] and [[Lake Päijänne|Päijänne]] stand with a subtly more pronounced relief.<ref name="Rudberg" /> The relief of the interior lake plateau bears some resemblance to the Swedish [[Norrland terrain]].<ref name="Natenterrang" /> Upland Finland and areas higher than 200 m are found mostly in the north and east of the country where hills and mountains exceed 500 m in height in these regions.<ref name="Rudberg" /> [[Inselberg#Geology|Inselberg plains]] are common in the northern half of the country.<ref>{{cite journal |last1=Ebert |first1=K. |last2=Hall |first2=A. |last3=Hättestrand |first3=C. |last4= Alm |first4=G. |date=2009 |title=Multi-phase development of a glaciated inselberg landscape |journal=[[Geomorphology (journal)|Geomorphology]] |volume=115 |issue=1 |pages=56–66 |doi= 10.1016/j.geomorph.2009.09.030}}</ref> In the northern region more known as [[Lapland (Finland)|Lapland]], highest points reach mostly from  200 m to 600 m and the landscape is a [[Fell#Förfjäll|förfjäll]] (fore-fell).<ref name="Natenterrang" /> However the most northern parts represent a more dramatic [[Scandinavian Mountains|mountain landscape]] where the [[Halti]] fell represents a highest point (1361 m) in the country.<ref name="britannicaFinland">{{cite encyclopedia |title=Finland |url=https://www.britannica.com/place/Finland |encyclopedia=[[Encyclopædia Britannica]] Online |location=Chicago |publisher=Encyclopædia Britannica, Inc |access-date=18 November 2017 |df=dmy-all }}</ref><ref>{{Cite web |last=PeakVisor |title=Finland Mountains |url=https://peakvisor.com/adm/finland.html |access-date=2024-05-20 |website=PeakVisor |language=en}}</ref>

The subdued landscape of Finland is the result of protracted erosion that has leveled down ancient mountain massifs into near-flat landforms called [[peneplain]]s.<ref name="UppslagsFiBERG" /> The last major leveling event resulted in the formation of the [[Sub-Cambrian peneplain]] in [[Neoproterozoic|Late Neoproterozoic]] time.<ref name="UppslagsFiBERG" /><ref name="japsenetal2016">{{cite journal |last1=Japsen |first1=Peter |last2=Green |first2=Paul F.|last3=Bonow |first3=Johan M.|last4=Erlström |first4=Mikael |date=2016 |title=Episodic burial and exhumation of the southern Baltic Shield: Epeirogenic uplifts during and after break-up of Pangaea |journal=[[Gondwana Research]] |volume=35 |pages=357–377 |doi= 10.1016/j.gr.2015.06.005}}</ref> While Finland has remained very close to sea-level since the formation of this last peneplain some further relief was formed by a slight uplift resulting in the [[river incision|carving of valleys]] by rivers. The slight uplift also means that at parts the uplifted peneplain can be traced as [[summit accordance]]s.<ref name="UppslagsFiBERG">{{cite web |url=http://uppslagsverket.fi/sv/sok/view-103684-BerggrundOchYtformer |title=berggrund och ytformer |last=Lindberg |first=Johan  |date=April 4, 2016 |website=[[Uppslagsverket Finland]] |access-date=November 30, 2017 |language=sv}}</ref> The [[Quaternary glaciation|Quaternary ice age]]s resulted in the erosion of weak rock and loose materials by glaciers. When the ice masses [[deglaciation|retreated]] eroded depressions turned into lakes.<ref name="UppslagsFiBERG" />{{efn-ua|Compare to southern Sweden where its large number of lakes would according to [[Alfred Gabriel Nathorst]] be indebted to the creation of basins due to the stripping of an irregular mantle of [[weathering|weathered rock]] by [[glacier erosion]].<ref name=Karnaetal1999>{{cite book |last1=Lidmar-Bergström |first1=K. |last2=Olsson |first2=S.|last3=Roaldset |first3=E.|author-link=Karna Lidmar-Bergström |date=1999 |chapter= Relief features and palaeoweathering remnants in formerly glaciated Scandinavian basement areas |title=Palaeoweathering, Palaeosurfaces and Related Continental Deposits |editor-last=Thiry |editor-first=Médard |editor-last2=Simon-Coinçon |editor-first2=Régine |publisher=Blackwell Science Ltd |pages= 275–301 |isbn=0-632-05311-9 |volume=27|series=Special publication of the International Association of Sedimentologists }}</ref>}} [[Joint (geology)|Fractures]] in Finland's bedrock were particularly affected by weathering and erosion, leaving as result trace straight sea and lake inlets.<ref name="UppslagsFiBERG" />

[[File:Uusimaa, Finland - panoramio - pan-opticon (22).jpg|thumb|The [[Kuhakoski]] rapids in [[Uusimaa]]]]
[[File:Ice-age glacial striation in Finland.jpg|thumb|200px|Effects of the last ice age: [[glacial striation]]s in a country without glaciers]]
Except a few rivers along the coasts most rivers in Finland drain at some stage into one or more lakes.<ref name=britannicaFinland/> The drainage basins drain into various directions. Much of Finland drains into the [[Gulf of Bothnia]] including the country's largest and longest rivers, [[Kokemäenjoki]] and [[Kemijoki]] respectively.<ref name=britannicaFinland/> Finland's largest lake drains by [[Vuoksi River]] into [[Lake Ladoga]] in Russia.<ref name=Natenterrang/><ref name=britannicaFinland/> Upland Finland in the east drains east across Russian [[Republic of Karelia]] into the [[White Sea]].<ref name=britannicaFinland/> In the northeast [[Lake Inari]] discharges by [[Paatsjoki]] into [[Barents Sea]] in the Arctic.<ref name=britannicaFinland/>

{| class="wikitable" align="right" style="width=70%; font-size:90%;border:1px solid darkgray;" border="1"
|+Localities in Finland by approximate date of deglaciation<ref name=Stroevenetal2016/> 
|-
| valign="top"|Year before present
| valign="top" style="text-align:center;"|Deglaciated
|-
| valign="top"|12,700
| align="right" valign="top"| [[Helsinki]], [[Kotka]]
|-
| valign="top"|11,000
| align="right" valign="top"| [[Turku]], [[Kuopio]]
|-
| valign="top"|10,900
| align="right" valign="top"| [[Jyväskylä]], [[Mariehamn]], [[Tampere]] 
|-
| valign="top"|10,800
| align="right" valign="top"| [[Lake Inari]]
|-
| valign="top"|10,700
| align="right" valign="top"| All of [[Åland]]
|-
| valign="top"|10,500
| align="right" valign="top"|[[Kajaani]]
|-
| valign="top"|10,300
| align="right" valign="top"|[[Vaasa|Vasa]], [[Oulu]]
|-
| valign="top"|10,200
| align="right" valign="top"|[[Rovaniemi]]
|-
| valign="top"|10,100
| align="right" valign="top"|[[Tornio]]
|-
|}