Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland
Lake Ähtärinjärvi, at the northern end of the River Kokemäenjoki watercourse in northern central Finland, has been known to have an older outlet channel across the modern Suomenselkä watershed to the Bothnian Bay. The ancient connection over the watershed is indicated by the existence of a conspicuo...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Geological Society of Finland
2006-06-01
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| Series: | Bulletin of the Geological Society of Finland |
| Subjects: | |
| Online Access: | http://www.geologinenseura.fi/bulletin/Volume78/seppatikkanen.pdf |
| _version_ | 1818063740400041984 |
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| author | H. Seppä M. Tikkanen |
| author_facet | H. Seppä M. Tikkanen |
| author_sort | H. Seppä |
| collection | DOAJ |
| description | Lake Ähtärinjärvi, at the northern end of the River Kokemäenjoki watercourse in northern central Finland, has been known to have an older outlet channel across the modern Suomenselkä watershed to the Bothnian Bay. The ancient connection over the watershed is indicated by the existence of a conspicuously deep and wide palaeochannel that runs from the northern end of Lake Ähtärinjärvi to the headwaters of the River Ähtävänjoki Radiocarbon datings of the basal sediments of the channel show that the flow in the old outlet channel ceased at about 1500 cal yr BP; the old channel therefore functioned as an outlet since the isolation of the lake at about 9900 cal yr BP to 1500 cal yr BP. Sedimentological studies of Lake Ouluvesi, located below the modern outlet of the lake system, suggest opening of the modern outlet at 3200 cal yr BP, indicating that the lake system had a 1700-year period of bifurcation before the final drying up of the old outlet channel. The reconstruction of the tilting of the lake level supports this pattern, and demonstrates further that during the early-Holocene the lake consisted of three basins located at different levels until the transgression caused by the tilting gradually brought the basins to the same level. |
| first_indexed | 2024-12-10T14:24:54Z |
| format | Article |
| id | doaj.art-9051feb603ef4f7b8859ea232b6438a7 |
| institution | Directory Open Access Journal |
| issn | 0367-5211 1799-4632 |
| language | English |
| last_indexed | 2024-12-10T14:24:54Z |
| publishDate | 2006-06-01 |
| publisher | Geological Society of Finland |
| record_format | Article |
| series | Bulletin of the Geological Society of Finland |
| spelling | doaj.art-9051feb603ef4f7b8859ea232b6438a72022-12-22T01:45:06ZengGeological Society of FinlandBulletin of the Geological Society of Finland0367-52111799-46322006-06-0178151810.17741/bgsf/78.1.001Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western FinlandH. SeppäM. TikkanenLake Ähtärinjärvi, at the northern end of the River Kokemäenjoki watercourse in northern central Finland, has been known to have an older outlet channel across the modern Suomenselkä watershed to the Bothnian Bay. The ancient connection over the watershed is indicated by the existence of a conspicuously deep and wide palaeochannel that runs from the northern end of Lake Ähtärinjärvi to the headwaters of the River Ähtävänjoki Radiocarbon datings of the basal sediments of the channel show that the flow in the old outlet channel ceased at about 1500 cal yr BP; the old channel therefore functioned as an outlet since the isolation of the lake at about 9900 cal yr BP to 1500 cal yr BP. Sedimentological studies of Lake Ouluvesi, located below the modern outlet of the lake system, suggest opening of the modern outlet at 3200 cal yr BP, indicating that the lake system had a 1700-year period of bifurcation before the final drying up of the old outlet channel. The reconstruction of the tilting of the lake level supports this pattern, and demonstrates further that during the early-Holocene the lake consisted of three basins located at different levels until the transgression caused by the tilting gradually brought the basins to the same level.http://www.geologinenseura.fi/bulletin/Volume78/seppatikkanen.pdfpaleolimnologylakesupliftslake-level changestransgressionoutletspaleochannelsHoloceneLake ÄhtärinjärviFinland |
| spellingShingle | H. Seppä M. Tikkanen Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland Bulletin of the Geological Society of Finland paleolimnology lakes uplifts lake-level changes transgression outlets paleochannels Holocene Lake Ähtärinjärvi Finland |
| title | Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland |
| title_full | Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland |
| title_fullStr | Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland |
| title_full_unstemmed | Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland |
| title_short | Land uplift-driven shift of the outlet of Lake Ähtärinjärvi, western Finland |
| title_sort | land uplift driven shift of the outlet of lake ahtarinjarvi western finland |
| topic | paleolimnology lakes uplifts lake-level changes transgression outlets paleochannels Holocene Lake Ähtärinjärvi Finland |
| url | http://www.geologinenseura.fi/bulletin/Volume78/seppatikkanen.pdf |
| work_keys_str_mv | AT hseppa landupliftdrivenshiftoftheoutletoflakeahtarinjarviwesternfinland AT mtikkanen landupliftdrivenshiftoftheoutletoflakeahtarinjarviwesternfinland |