Chapter Hazard Analysis

Probability of Earthquake Event in The New Madrid Seismic Zone

Richter	Year 2000	Year 2035
6.3	40% - 63%	86% - 97%
7.6	5.4% - 8.7%	19% - 29%
8.3	0.3% - 1.0%	2.7% - 4.0%
Source: Illinois State Geological Survey

lthough it is estimated that the earthquakes of 1811 and 1812 are likely to occur once every 500 to 600 years, it is still likely that a damaging earthquake (6.0 to 7.6 on the Richter Scale) is likely to occur in this lifetime. The table to the right shows the estimated probability of damaging earthquakes in Illinois.

According to the Central U.S. Earthquake Consortium, Kane County is in an earthquake intensity zone of VI (MMI Scale) for a 7.6-magnitude earthquake along the New Madrid Seismic Zone. There is a 19% – 29% chance that the County will be hit with an earthquake with a MMI intensity of VI over the next 35 years. This would be slightly less than a 1% chance in any given year. As noted in the table on page 2-32, this level of quake would be felt by everyone, but would cause minor structural damage.

It is important to note that the level of damage is dependent on the location of the earthquake. There are faults and other potential sources of a quake closer to Kane County than New Madrid, Missouri.

Safety: Approximately 1,600 people have been killed by earthquakes in the US since colonial times, 1,000 of them were in California and 700 of those were in the 1906 San Francisco quake. “Trauma caused by partial or complete collapse of human-made structures is the overwhelming cause of death and injury in most earthquakes.” (The Public Health Consequences of Disasters, pages 18 – 19.)

V