Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Submarine Landslides in Lake Orsa, central Sweden
Stockholm University, Faculty of Science, Department of Geological Sciences.
2019 (English)Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Abstract [en]

Lake Orsa is situated in the county of Dalarna in central Sweden. The lake is part of the Siljan Ring, which formed approximately 380 Ma by the largest known impact in Europe. The area is of high interest due to its location during the Weichselian deglaciation. The deglacial history in the area is complex, and the behavior of the receding ice sheet is to some extent not yet fully understood. Submarine landslides were revealed during a geophysical survey, aimed as a site study for a drilling project with the purpose to retrieve an undisturbed sedimentary sequence for studying late- to postglacial evolution in the area. The largest landslide in Lake Orsa mobilized more than 620 000 m3 of sediment. It has a length of over 630 m and is over 400 m wide. The slides in Lake Orsa are characterized as both confined and emergent submarine landslides. Units with different sedimentological properties have been identified, with a plausible weak horizon in between. The upper unit is believed to prevent up-ward movement of water or gas, possibly leading to overpressure in the lower sediments. The landslides are thought to have occurred during several occasions and seem not to be related to one single event. Plausible causes may be a combination of steep slopes, overpressure zones, and/or low strength horizons in the sub-bottom. The landslides in Lake Orsa have several similarities with the Finneidfjord slide which occurred in northern Norway 1996. The slide was responsible for the loss of four human lives and destroyed nearby houses and a road. Characterizing and understanding submarine landslides are thus an important task to be able to protect citizens as well as infrastructure. Dating the landslides will be possible once the retrieved sediment core during the drilling campaign in one of the slide deposits has been analysed. Relating the slides to the postglacial evolution of the area has proven to be difficult without an age.

Place, publisher, year, edition, pages
2019.
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:su:diva-169512OAI: oai:DiVA.org:su-169512DiVA, id: diva2:1321805
Supervisors
Examiners
Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-06-10Bibliographically approved

Open Access in DiVA

fulltext(2252 kB)9 downloads
File information
File name FULLTEXT01.pdfFile size 2252 kBChecksum SHA-512
342b64701e91f3b22ac0e0e6826733357eb55563c9dec0c0536b2427a9ab4d665755cbe6c7cfa5249c997ae11253f77ee6075e7291aa50935090ecc1e064bb7d
Type fulltextMimetype application/pdf

By organisation
Department of Geological Sciences
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 9 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 19 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf