1929 Earthquake: The Laurentian Slope Disaster

Go to

Click on Historic Events. Read the introduction link on Earthquake zones page and click on Background on earthquakes in eastern Canada

  1. A) Would you consider the eastern coast of Canada to be tectonically stable?Explain.

B)Each year, ~ ______earthquakes occur in eastern Canada. Of this number, perhaps _____ will exceed magnitude 4, _____ will exceed magnitude 3, and ~ ______events will be reported felt. Every 10 years, on average, include three events greater than M______.

C)The causes of earthquakes in eastern Canada are not well understood. Why? What could be a reason for the quakes?

D)On average, an earthquake occurs in the Charlevoix region occurs ______. A Lower St. Lawrence earthquake occurs ______on average.

E)Which Seismic Zone has the greatest number of e’quakes? Possible reason?

The least? Possible reason?

  1. At the bottom of the Laurentian Slope link there is another link about the 1929 quake. ( Click on this, scroll down to view the isoseimal map. Click on the Rossi-Forel link. What is the 1883 Rossi-Forel Scale of Earthquake Intensity? Explain the scale, and list the effects expected for the value assigned to this quake.
  2. Going back to the 1929 link, describe the tsunami and its resulting damage that struck the area approximately 2.5 h after the quake.
  1. Give examples of some of the survivors’ stories and experiences – what were some strange circumstances or “miracles”?
  1. Read some of the newspaper accounts. What was the general feeling about this occurrence? Were people surprised or was this a common enough situation to experience?
  1. From the home page, click on Be Prepared on the left menu bar, and then look at How would your home stand up? Assess your situation – and on a scale of one to 5 (1 = not good; 5 = very safe), figure out an approximate rating.
  1. Go to the Historic Earthquakes link and click on the Canada's Earthquakes: 'The Good, the Bad and the Ugly' ( ; go to the Saguenay link. Describe the type of damage observed according to the Mercalli scale. Why was Montreal particularly affected? Explain.
  1. Read about the Cornwall quake – why was there so much damage? Would we have felt this quake in NS? Explain your answer.
  1. Read about the Charlevoix quake – why was this quake considered particularly significant? Explain your answer.
  1. Read about the 1700 quake along the Cascadia Subduction fault. How do you think they assigned the quake a magnitude of 9 on the Richter scale?
  1. Go to What is a megathrust earthquake? How is it different from a normal quake?(Another excellent reference and selection of stories -

Give five pieces of evidence of this ancient quake off the west coast.