| Title | Deglacial and postglacial paleoseismological archives in mass-movement deposits of lakes of south-central Quebec |
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| Author | Trottier, A -P; Lajeunesse, P; Normandeau, A ; Gagnon-Poiré, A |
| Source | ISC2018 - 20th International Sedimentological Congress, abstract volume; 2018 p. 1 |
| Image |  |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180225 |
| Publisher | IAS |
| Meeting | ISC2018 - 20th International Sedimentological Congress; Québec, QC; CA; August 13-17, 2018 |
| Document | Web site |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf |
| Province | Quebec |
| NTS | 21E; 21L; 21M; 21N; 22C; 22D; 31F; 31G; 31H; 31I; 31J; 31K; 31L; 31M; 31N; 31O; 31P; 32A; 32B; 32C; 32D |
| Area | Maskinongé Lake; Lac-aux-Sables; Lake Saint-Joseph |
| Lat/Long WENS | -80.0000 -68.0000 49.0000 45.0000 |
| Subjects | surficial geology/geomorphology; geophysics; stratigraphy; seismology; earthquakes; glacial history; deglaciation; glacial deposits; postglacial deposits; landslide deposits; surface waters; lakes;
geophysical surveys; acoustic surveys; bathymetry; core samples; deposition; Western Québec Seismic Zone; Charlevoix-Kamouraska Seismic Zone; lacustrine sediments; Phanerozoic; Cenozoic; Quaternary |
| Program | Public Safety
Geoscience Marine Geohazards |
| Program | NSERC Natural Sciences and Engineering Research Council of
Canada |
| Released | 2018 08 01 |
| Abstract | Investigation of seismic activity in southern Québec is important for natural hazard management since two major active seismic zones with many historical records are located in the region: the Western
Québec and the Charlevoix-Kamouraska seismic zones, with the latter being the most active in northeastern America. This poster describes a dataset of high-resolution bathymetry imagery, subbottom profiles and sediments cores collected in three lakes
(Maskinongé, Lac-aux-Sables and Lake Saint-Joseph) located between two active seismic zones, in south-central Québec. The lacustrine geomorphology observed on high resolution swath bathymetry imagery, acoustic subbottom profiles and the sediment
analysis indicate that the lakes were disturbed by seismically-induced mass-movements since deglaciation. Mass-movement deposits (MMDs) were observed on subbottom profiles at three different stratigraphic levels. The position of the MMDs in the
stratigraphic sequence of the region and the use of the depositional rate from 210Pb activity on sediment cores from each lake allow the identification of three distinct and major earthquake events: 1) during deglaciation between ~11.1 and 10 ka cal.
BP; 2) around 810 ± 370 AD; and 3) the well documented 1663 AD M>7 historical earthquake. The second earthquake event that occurred prior the the 1663 AD event is responsible for remobilizing the largest volume of sediments in the entire
stratigraphic sequences of the lakes. However, this event did not necessarily reached a higher magnitude than the historical 1663 earthquake, as its epicenter could have been located closer to the studied lakes or sediments could have been more
readily available to be remobilized when it occurred. |
| Summary | (Plain Language Summary, not published)
We identified and dated sublacustrine landslides in southern Québec triggered by earthquakes during the past 10000 years, allowing us to refine the
history of earthquakes in southeastern Québec. |
| GEOSCAN ID | 311307 |
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