Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments
Eastern North America experiences large intracratonic earthquakes that are not well understood but pose a risk to urban centers and other infrastructure. Compilation of regional earthquake epicentres for south-central Ontario and western Quebec demonstrate a close association with sutures and failed...
Main Author: | |
---|---|
Other Authors: | , |
Format: | Thesis |
Language: | English |
Published: |
2014
|
Subjects: | |
Online Access: | http://hdl.handle.net/11375/15480 |
id |
ftmcmaster:oai:macsphere.mcmaster.ca:11375/15480 |
---|---|
record_format |
openpolar |
spelling |
ftmcmaster:oai:macsphere.mcmaster.ca:11375/15480 2023-05-15T16:41:20+02:00 Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments Doughty, Michael Eyles, Carolyn Geography and Earth Sciences 2014 http://hdl.handle.net/11375/15480 en eng http://hdl.handle.net/11375/15480 mid-plate seismicity lake sediments sub-bottom profiling co-seismic deformation Thesis 2014 ftmcmaster 2022-03-22T21:12:27Z Eastern North America experiences large intracratonic earthquakes that are not well understood but pose a risk to urban centers and other infrastructure. Compilation of regional earthquake epicentres for south-central Ontario and western Quebec demonstrate a close association with sutures and failed rifts (the St. Lawrence Rift) recording the formation and breakup respectively of successive supercontinents Rodinia and Pangea. Where seismic potential could be underestimated through lack of historical seismicity or where little is known about active faults, lake deposits can provide a valuable record of past seismic shaking events in the form of sediment deformation structures (i.e. ‘seismites’). In central Canada, the lacustrine seismographic record began approximately 10,000 years before present with the retreat of the Laurentide Ice Sheet, older records having been removed by glacial erosion. Most bedrock lake basins are structurally-controlled and underlain by the same Precambrian basement structures (shear zones, terrane boundaries and other lineaments) implicated as the source of ongoing mid-plate earthquake activity. High resolution seismo-stratigraphic data presented here supports the model that ongoing mid-plate earthquake activity is a consequence of brittle deformation of the upper crust of the North American plate. Such activity appears to have been greatest during deglaciation but continues today. The detailed geophysical and sedimentary studies, as shown here, have major societal relevance in areas of eastern North America affected by intraplate earthquakes. The recognition and mapping of earthquake related features in lakes for seismic risk analysis is a means of constraining seismic recurrence intervals and more realistically assess seismic risk across the populated area of Ontario and Quebec where events occur on time scales much longer than recorded history. Dissertation Doctor of Philosophy (PhD) Thesis Ice Sheet MacSphere (McMaster University) Canada |
institution |
Open Polar |
collection |
MacSphere (McMaster University) |
op_collection_id |
ftmcmaster |
language |
English |
topic |
mid-plate seismicity lake sediments sub-bottom profiling co-seismic deformation |
spellingShingle |
mid-plate seismicity lake sediments sub-bottom profiling co-seismic deformation Doughty, Michael Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments |
topic_facet |
mid-plate seismicity lake sediments sub-bottom profiling co-seismic deformation |
description |
Eastern North America experiences large intracratonic earthquakes that are not well understood but pose a risk to urban centers and other infrastructure. Compilation of regional earthquake epicentres for south-central Ontario and western Quebec demonstrate a close association with sutures and failed rifts (the St. Lawrence Rift) recording the formation and breakup respectively of successive supercontinents Rodinia and Pangea. Where seismic potential could be underestimated through lack of historical seismicity or where little is known about active faults, lake deposits can provide a valuable record of past seismic shaking events in the form of sediment deformation structures (i.e. ‘seismites’). In central Canada, the lacustrine seismographic record began approximately 10,000 years before present with the retreat of the Laurentide Ice Sheet, older records having been removed by glacial erosion. Most bedrock lake basins are structurally-controlled and underlain by the same Precambrian basement structures (shear zones, terrane boundaries and other lineaments) implicated as the source of ongoing mid-plate earthquake activity. High resolution seismo-stratigraphic data presented here supports the model that ongoing mid-plate earthquake activity is a consequence of brittle deformation of the upper crust of the North American plate. Such activity appears to have been greatest during deglaciation but continues today. The detailed geophysical and sedimentary studies, as shown here, have major societal relevance in areas of eastern North America affected by intraplate earthquakes. The recognition and mapping of earthquake related features in lakes for seismic risk analysis is a means of constraining seismic recurrence intervals and more realistically assess seismic risk across the populated area of Ontario and Quebec where events occur on time scales much longer than recorded history. Dissertation Doctor of Philosophy (PhD) |
author2 |
Eyles, Carolyn Geography and Earth Sciences |
format |
Thesis |
author |
Doughty, Michael |
author_facet |
Doughty, Michael |
author_sort |
Doughty, Michael |
title |
Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments |
title_short |
Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments |
title_full |
Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments |
title_fullStr |
Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments |
title_full_unstemmed |
Postglacial Seismicity in Ontario-Quebec Determined Through Analysis of Deformation Stuctures in Lake Sediments |
title_sort |
postglacial seismicity in ontario-quebec determined through analysis of deformation stuctures in lake sediments |
publishDate |
2014 |
url |
http://hdl.handle.net/11375/15480 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
http://hdl.handle.net/11375/15480 |
_version_ |
1766031766536060928 |