| Titre | Earthquake Waves: The Damaging Cornwall, Ontario Earthquake of 1944 |
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| Auteur | Cassidy, J F |
| Source | L'Association Canadienne du Génie Parasismique, Bulletin vol. 7, issue 1, 2022 p. 1-2 |
| Image |  |
| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210522 |
| Éditeur | Association canadienne du génie parasismique |
| Document | publication en série |
| Lang. | anglais |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Ontario; Québec |
| SNRC | 30; 31; 21E; 21L; 21M |
| Lat/Long OENS | -80.0000 -70.0000 48.0000 40.0000 |
| Sujets | secousses séismiques; ondes sismiques; dégât causés par les tremblements de terre; Vallée du Saint-Laurent; tectonique |
| Illustrations | cartes de localisation |
| Programme | Géoscience pour la sécurité publique Risques géologique du tremblement de terre |
| Diffusé | 2022 01 01 |
| Résumé | (disponible en anglais seulement)
Canada has remained quiet in terms of significant earthquakes during the past few months. As a result, this column will again highlight a significant historic
Canadian earthquake - this one in eastern Ontario, near the St. Lawrence River. At 12:38 a.m. (Eastern time) on September 5, 1944, a damaging Mw5.8 earthquake occurred between Cornwall, Ontario and Massena, New York. Shaking was felt from Quebec City
to Toronto to New York City to Lake Michigan (and most points in between). Pictures and dishes came crashing down, water pipes broke, plaster walls cracked and many cemetery headstones were rotated (these rotation patterns were later used to study
the location and faulting style of this earthquake). This earthquake caused an estimated $10-15 million (2021 dollars) of damage in, and within ~50 km of Cornwall, ON (where about 2000 chimneys were damaged in this community of ~15,000 people at the
time), and also caused significant damage in nearby Massena, New York (where 90% of the chimneys were damaged or destroyed). Substantial damage occurred at the Collegiate and Vocational School, a two-storey brick building in Cornwall. The
out-of-plane failure of a top-floor unreinforced masonry wall was surprising, given the moderate magnitude (Mw5.8) of this earthquake, but a clear reminder of the risk (especially to older buildings) in the seismically active areas of eastern Canada.
Modern studies of this earthquake revealed oblique thrust faulting (combination thrust and strike slip) at a depth of ~20 km. The faulting style is similar to smaller, recent earthquakes, and consistent with an ENE-oriented crustal stress field
mapped in this region. There is also evidence of the significant role of local geology. Much of the damage coincided with structures built in areas underlain by the Leda Clay (ancient glacial lake sediments) of the St. Lawrence River valley. There
were numerous impacts to these soft soils (e.g., fissures, liquefaction, water well effects - with some drying up and others overflowing) - a clear reminder of the importance of geological engineering here, and in all earthquake-prone regions. This
earthquake was followed by numerous felt aftershocks, reminding us that the effects and impacts of a significant earthquake will last for days, weeks or sometimes months. For additional information on this earthquake, see Bruneau and Lamontagne
(1994). |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cette série d'articles « Earthquake Waves » rappelle les séismes importants qui ont touché le Canada. Cet article résume le tremblement de terre
dommageable de 1944 à Cornwall, en Ontario (Magnitude 5,8), y compris les effets sur les structures de la région, les observations de liquéfaction, la zone où le tremblement de terre a été ressenti (dans une grande partie de l'est du Canada et du
nord-est des États-Unis), les répliques et la cause de ce séisme (contraintes crustales). |
| GEOSCAN ID | 329401 |
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