Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift
Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise...
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ftdoajarticles:oai:doaj.org/article:48d629fa268d4d2ea13f1445090c63fb 2023-05-15T16:40:45+02:00 Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift A.J. (Tom) van Loon Małgorzata Pisarska-Jamroży Māris Nartišs Māris Krievāns Juris Soms 2016-09-01T00:00:00Z https://doi.org/10.1016/j.jop.2016.05.002 https://doaj.org/article/48d629fa268d4d2ea13f1445090c63fb EN eng Elsevier http://www.sciencedirect.com/science/article/pii/S2095383616300220 https://doaj.org/toc/2095-3836 2095-3836 doi:10.1016/j.jop.2016.05.002 https://doaj.org/article/48d629fa268d4d2ea13f1445090c63fb Journal of Palaeogeography, Vol 5, Iss 4, Pp 363-380 (2016) Soft-sediment deformation structures (SSDS) Seismites Latvia Glacio-isostatic rebound Earthquake recurrence time Paleontology QE701-760 article 2016 ftdoajarticles https://doi.org/10.1016/j.jop.2016.05.002 2022-12-31T16:18:21Z Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a Baltic country that was covered by an ice sheet during the last glaciation. The seismites were found at two sites: Near Valmiera in the NE part and near Rakuti in the SE part of the country. The seismites were found in sections of about 7 m and 4.5 m high, respectively, that consist mainly of glaciofluvial and glaciolacustrine sands and silts. At the Valmiera site, 7 seismites were found, and at the Rakuti site these were even 12 seismites. The two sections have not been dated precisely up till now, but lithological correlations and geomorphological characteristics suggest that the sediments at the Valmiera site cannot be older than 14.5 ka. Because the accumulation of the section did not take more than about 1000 years, the average recurrence time of the high-magnitude (M ≥ 4.5–5.0) earthquakes must have been maximally only 100–150 years, possibly only 6–7 years. The sediments at Rakuti must also have formed within approx. 1000 years (17–16 ka), implying a recurrence time of high-magnitude earthquakes of maximally once per 100–200 years. Article in Journal/Newspaper Ice Sheet Directory of Open Access Journals: DOAJ Articles Journal of Palaeogeography 5 4 363 380 |
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op_collection_id |
ftdoajarticles |
language |
English |
topic |
Soft-sediment deformation structures (SSDS) Seismites Latvia Glacio-isostatic rebound Earthquake recurrence time Paleontology QE701-760 |
spellingShingle |
Soft-sediment deformation structures (SSDS) Seismites Latvia Glacio-isostatic rebound Earthquake recurrence time Paleontology QE701-760 A.J. (Tom) van Loon Małgorzata Pisarska-Jamroży Māris Nartišs Māris Krievāns Juris Soms Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift |
topic_facet |
Soft-sediment deformation structures (SSDS) Seismites Latvia Glacio-isostatic rebound Earthquake recurrence time Paleontology QE701-760 |
description |
Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a Baltic country that was covered by an ice sheet during the last glaciation. The seismites were found at two sites: Near Valmiera in the NE part and near Rakuti in the SE part of the country. The seismites were found in sections of about 7 m and 4.5 m high, respectively, that consist mainly of glaciofluvial and glaciolacustrine sands and silts. At the Valmiera site, 7 seismites were found, and at the Rakuti site these were even 12 seismites. The two sections have not been dated precisely up till now, but lithological correlations and geomorphological characteristics suggest that the sediments at the Valmiera site cannot be older than 14.5 ka. Because the accumulation of the section did not take more than about 1000 years, the average recurrence time of the high-magnitude (M ≥ 4.5–5.0) earthquakes must have been maximally only 100–150 years, possibly only 6–7 years. The sediments at Rakuti must also have formed within approx. 1000 years (17–16 ka), implying a recurrence time of high-magnitude earthquakes of maximally once per 100–200 years. |
format |
Article in Journal/Newspaper |
author |
A.J. (Tom) van Loon Małgorzata Pisarska-Jamroży Māris Nartišs Māris Krievāns Juris Soms |
author_facet |
A.J. (Tom) van Loon Małgorzata Pisarska-Jamroży Māris Nartišs Māris Krievāns Juris Soms |
author_sort |
A.J. (Tom) van Loon |
title |
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift |
title_short |
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift |
title_full |
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift |
title_fullStr |
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift |
title_full_unstemmed |
Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift |
title_sort |
seismites resulting from high-frequency, high-magnitude earthquakes in latvia caused by late glacial glacio-isostatic uplift |
publisher |
Elsevier |
publishDate |
2016 |
url |
https://doi.org/10.1016/j.jop.2016.05.002 https://doaj.org/article/48d629fa268d4d2ea13f1445090c63fb |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Journal of Palaeogeography, Vol 5, Iss 4, Pp 363-380 (2016) |
op_relation |
http://www.sciencedirect.com/science/article/pii/S2095383616300220 https://doaj.org/toc/2095-3836 2095-3836 doi:10.1016/j.jop.2016.05.002 https://doaj.org/article/48d629fa268d4d2ea13f1445090c63fb |
op_doi |
https://doi.org/10.1016/j.jop.2016.05.002 |
container_title |
Journal of Palaeogeography |
container_volume |
5 |
container_issue |
4 |
container_start_page |
363 |
op_container_end_page |
380 |
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1766031170454159360 |