Kvarken Archipelago Example of glacial landforms – Laser DEM Jaakko Auri and Olli Breilin Geological Survey of Finland (GTK) Kokkola HC/KA Workshop 14.11.2013, Vaasa J.Auri and O.Breilin 14.11.2013 1 Carta Marina 1539 Bishop Olaus Magnus J.Auri and O.Breilin 14.11.2013 2 Kvarken Archipelago with numbers •Area 194 400 ha, 85 % sea area •Coast line 2416 km •Number of islands and islets 5600 •Inhabitants 2500 •Water depth 10 – 15 m, deepest course 25 metres near Holmö Island (Sweden) •Brackish water, salt content 4-5 ‰ •Ice covered 140-150 days per year •Water flow 17 000 m3 per second (from NE to SW) •The total size of the KA/HC transboundary serial property is 336,900 hectares. J.Auri and O.Breilin 14.11.2013 3 Deglaciation - The history of the Baltic Sea Baltic Ice Lake (early) Ancylus Lake Baltic Ice Lake (late) Yoldia Sea Litorina Sea M. Saarnisto (2003), drawings O. Sallasmaa Possible strait connections between Baltic Ice Niko Putkinen (2011). Late Weichselian deglaciation chronology and lake and ice lake in White Sea area 12 000 BP palaeoenvironments in northern Karelia, NW Russia. Geological Survey of Finland, Espoo 2011. J.Auri and O.Breilin 14.11.2013 4 Glacial isostatic land uplift Year 4000 Picture Hanna Virkki (GTK) Botnian Bay High Caost Kvarken Archipelago Botnian Sea Ågren & Svensson 2007 Baltic Sea ”The main ongoing geological process – changes the shoreline and scenery in a span of human life time.” J.Auri and O.Breilin 14.11.2013 5 Land is arising from the sea, Gåsgrund 1978 ja 2006 © Metsähallitus, Photo Seppo Lammi 2006 J.Auri and O.Breilin 14.11.2013 6 Geology of central area of the Kvarken Archiplago Based on 1:20 000 mapping of Quaternary deposits and formations (Genat 2002 – 2005) Glacial till Glacial formations, De Geer-moraines Glacial formations, Ribbed-moraines Deep water sediments, silt and clay Glaciofluvial formations, sand and gravel (esker) Littoral deposits, sand and gravel Bedrock outcrops N 10 km J.Auri and O.Breilin 14.11.2013 7 Complex flow pattern of the continental ice sheet Age Relation of the Striations Undefined age relation The Youngest Local Direction Older Local Direction The Oldest Local Direction Picture Jukka Ojalainen,GTK J.Auri and O.Breilin 14.11.2013 8 Complex flow pattern of the continental ice sheet Hundreds observations of striations – Normally 2, often 3 and even 5 different directions 45º 310º N 355º Picture and interpretation Jukka Ojalainen, GTK J.Auri and O.Breilin 14.11.2013 9 Geodiversity on glaciated terrain Glacial formations and features created by continental ice sheet Drumlins Flutings Ribbed - moraines De Geer - moraines Hummocky moraine Boulder field Deep water sediments, clay/silt Continental ice sheet J.Auri and O.Breilin Drawings Harri Kutvonen (GTK) 14.11.2013 10 De Geer moraine – field, Svedjehamn, Björkö © Metsähallitus, Photo Seppo Lammi 2006 J.Auri and O.Breilin 14.11.2013 11 Interpretation by Niko Putkinen J.Auri and O.Breilin 14.11.2013 12 Björkö / Svedjehamn De Geer moraines Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 13 Björkö De Geer moraines Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 14 Djupskäret Small bedrock outcrops / flutings / De Geer moraines Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 15 Haggisgrund Drumlins / Flutings / De Geer moraines Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 16 Ribbed – moraines, Valassaaret-islands Picture © Metsähallitus J.Auri and O.Breilin 14.11.2013 17 Lappören Ribbed moraines / De Geer moraines Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 18 Flada-klu – lagoon-lake series , Lappören © Metsähallitus, Photo Seppo Lammi 2006 J.Auri and O.Breilin 14.11.2013 19 Märaskäret Ribbed moraines / De Geer moraines / beach ridges Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 20 Littoral deposits Raised beaches and on going littoral processes. Photos Olli Breilin (upper) ja Jukka Ojalainen (lower), Drawings Harri Kutvonen Märäskäret Norrskär J.Auri and O.Breilin 14.11.2013 21 Norrskat Ribbed moraines / De Geer moraines Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 22 Slåttskäret Ribbed moraines / De Geer moraines / Drumlins Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 23 Bergö gaddarna Rocky terrain / bedrock outcrops Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 24 Mickelsörarna Ribbed moraine / fluting Laser scanning and map © Maanmittauslaitos J.Auri and O.Breilin 14.11.2013 25 Rönnskäret / underwater formations (ULTRA) J.Auri and O.Breilin 14.11.2013 26 Thank you for your attention ! “Sampling” at Norra Djupörbådan © Photo Hannu Kujala;GTK 2004 J.Auri and O.Breilin 14.11.2013 27
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