October 27, 1998
To:Emergency and Protective Services Committee
From:Fire Chief Alan F. Speed
Subject:Earthquake Probabilities and Preparedness
Purpose:
This report responds to questions raised in the letter presented by Councillor Frances Nunziata at the Emergency and
Protective Services Committee meeting held on October 6, 1998.
Recommendations:
That this report be received as information.
Council Reference/Background/History:
Letter from Councillor Nunziata, September 28, 1998 re: Earthquake, Northeastern Pennsylvania, September 25, 1998.
Comments and/or Discussion and/or Justification:
Councillor Nunziata, in a letter to the Mayor on September 28, raised four questions regarding the potential of an
earthquake occurring here and the safety of the residents of the City in the event one strikes.
1. "Media reports, 'September 25th earthquake, A warning of more to come.' Is this true?"
The September 25th earthquake was centred in the United States, approx. 75 kms SSE of Erie, Pennsylvania, 300 kms
from Toronto. The seismic waves that reached Canada were non-damaging and only slightly noticeable. It was noticed
here largely because the underlaying rock structure in Eastern North America is more dense than the rest of the continent,
making seismic waves noticeable at greater distances from the epicenter of the quake.
The western end of the Lake Ontario Basin, [Toronto and area] is an area of seismic stability and does not have a history
of damaging events. Probability of earthquakes occurring is partially judged using past history, and in this case, there is no
history to support the, "More to come," claim. This in no way means that we shouldn't maintain or improve our levels of
emergency preparedness, only that earthquakes are not generally an imminent danger.
The lack of seismic events in this area is also noted by the National Building Code. Used by architects and designers, it
provides construction standards for structures. The code also prescribes environmental needs in differing geographic and
climatic areas across Canada.
One of the references in the Code is the National Seismic Index. The index gives probabilities of occurrence and estimates
of strength of seismic events that a structure may need to withstand. The ratings range from 0, which is extremely low
probability/strength to 6, which is extremely high. The table below shows the rating for Toronto, Ottawa and Vancouver
based on this system.
|
City |
Primary Factor
[Za] |
Secondary Factor
[Zv] |
|
Toronto |
0 |
1 |
|
Ottawa |
2 |
4 |
|
Vancouver |
4 |
4 |
Measurement: 0=Ext. Low; 6=Ext. High
Za=acceleration-related risk [a factor affecting the design of small buildings]
Zv=velocity related risk [a factor affecting the design of large buildings(3 stories or greater)]
This lack of activity doesn't mean that we won't have an earthquake. Probabilities being what they are, we can never say
that a major earthquake will not happen in our City. However, the likelihood of such an event is low.
2. "Two Fault lines intersect under Lake Ontario under the Pickering Nuclear Hydro Generating Station. These are
deeply fractured and seismically active."
There are fault lines wherever stresses on the earth's plates have caused them. Once a fault is produced, for whatever
reason, it is there forever. Many faults are undetected. Most faults are not visible, unlike the San Andreas fault in
California, which is an example of both a very visible and very active fault.
When considering the risk associated with a fault, its activity is the measure of the risk associated with it. The Lake
Ontario/Pickering fault has no recorded history of activity. According to Robert Wetmiller of the Earthquake Seismology
office in Ottawa, any predictions that this fault is active or about to become active are purely, "Speculative." There is no
evidence that this fault has ever been active since recordings of these events began.
3. "What emergency planning information is available? What procedures are in place to deal with situations like this?"
Personnel of the City are actively involved in Emergency Planning. The City has an Emergency Plan Bylaw, #47-1998.
This bylaw draws its authority from the Emergency Plans Act, R.S.O. 1990, an act allowing municipalities to design
emergency plans and enact them when necessary. The Toronto Emergency Plan would be enacted in the event of a major
incident.
Our Emergency Plan is used to clarify roles and identify extra resources available to the City if a situation arose that
would overwhelm the day-to-day resources available to the organization. Roles for City staff have been designated and
responsibilities established to restore the City to normal function as quickly and safely as possible.
The Mayor enacts the Emergency Plan with advice from one or all of the following personnel: Fire Chief, Police Chief,
Medical Officer of Health or Commissioner of Works and Emergency Services through the Municipal Control Group.
The Municipal Control Group is comprised of elected and appointed officials whose role is to assess events as they occur
and agree on a course of action to overcome problems or situations.
The Department is in the research and development phase of Heavy Urban Search And Rescue, [HUSAR]. This emerging
technology deals with the rescue of people entrapped by structural collapse. HUSAR is an excellent response tool in these
situations as staff will be capable of dealing with these incidents more efficiently whether or not it is caused by the
environment or is human-induced.
4. "What emergency procedures have been coordinated between the City and Ontario Hydro?"
The Toronto Nuclear Emergency Plan is a supplement to the Toronto Emergency Plan. It has been established to
safeguard the public in the event of a nuclear emergency. This Plan complies with the Provincial Nuclear Emergency
Plan, which addresses the safety needs of communities in proximity to nuclear facilities.
The Metro Regional Nuclear Preparedness Committee is made up of personnel from the following services:
<Toronto Public Health
<Toronto Fire
<Toronto Police
<Toronto Ambulance
<Toronto Community and Neighbourhood Services
<Toronto Works and Emergency Services
<Toronto Separate School Board
<Toronto District School Board
<Toronto Transit Commission
<Emergency Measures Ontario
Ontario Hydro
This committee meets on a regular basis, bringing information to the table for analysis and action. This group will also,
from time to time, oversee training exercises to test the validity of the plan and introduce refinements to ensure it's
efficiency in the event of a true emergency.
Conclusions:
Emergency planning is a living process. We must work at this constantly to ensure that our staff foresee, to the best of
their ability, potential dangers posed to the City and communities therein.
Given the information currently available, we believe that the City is not at great risk from an earthquake.
That being said, we should continue to consider this natural phenomenon when dealing with emergency planning, and in
some respects, building design.
Contact Name:
Alan F. Speed
Fire Chief
Tel: 397-4300
Alan F. Speed
Fire Chief
Barry Gutteridge
Commissioner, Works and Emergency Services
SC
