As we reflect upon the two year anniversary of the devastating M7.0 earthquake in Haiti, and approach the bicentennial of the 1811-1812 New Madrid earthquake sequence, many parallels may be drawn. Looking at these two events, there are numerous similarities that can inform the preparedness efforts we can effect now, in the United States, to keep buildings safe and businesses operational when the next significant event occurs in the New Madrid Seismic Zone.
One of the most striking similarities is the historical context of the timeframes and generational memories of the inhabitants within the regions. Prior to the Haiti earthquake of 2010 just over two hundred years had elapsed since a previous similarly devastating event had occurred. Further, like the New Madrid region, the expected frequency of large earthquakes is measured in centuries rather than decades.
Absence of Historic Context
As our conversations with residents of Port-au-Prince found, this long time period allowed generations to come and go without passing along prominent memories or personal stories of past experiences to influence the present or future mindset of the current populations.
This absence of context for potential earthquakes creates a lack of awareness and therefore, a false sense of security and certainly a lack of urgency for those living within the potentially affected areas.
When asked where significant earthquakes occur in the United States, most of the population will quickly identify the states of California, Alaska, and possibly Hawaii. Some individuals may even include Oregon and Washington, but few individuals will identify the Central United States as a region that could be affected and in fact has felt the effects of a major earthquake. An example of this lack of awareness and urgency can be measured by the participation in preparedness drills; last year’s Great Central U.S. Shakeout drew an approximate 3 million participants or under 5% of the populations of the eight states most likely to be affected by an event within the New Madrid Fault zone, by comparison last year’s Great California Shakeout drew over 8.5 million participants, approximately 25% of the state’s population.
Lessons from Haiti
So what should the remaining 95% of the New Madrid region’s residents learn from Haiti, and why should they care?
On January 12, 2010, the Republic of Haiti was struck by a M7.0 earthquake. According to USGS, during the 20th century and prior to this event, seismic activity within the island of Hispaniola had been concentrated on the eastern 2/3 of the island in the Dominican Republic, with only one earthquake in the Port-au-Prince region since 1964 registering greater than M4.0. Historically, though, larger (>M7.0) earthquakes have affected the region in 1701, 1751, 1770, and 1860 due largely to movement of the east-west-oriented Enriquillo Fault located just south of Port-au-Prince.
From December 1811 to February 1812, a series of three earthquakes with a magnitude of 7.0 or greater rocked New Madrid Seismic Zone. According to USGS, the main shocks were followed by many hundreds of aftershocks that lasted for decades. Many of the aftershocks were major earthquakes themselves. The area that was strongly shaken by the three main shocks was 2–3 times as large as the area shaken by the 1964 M9.2 Alaskan earthquake, and 10 times as large as that of the 1906 M7.8 San Francisco earthquake.
New Madrid Seismic Zone
It is estimated that the ground motion for a possible major earthquake event in the New Madrid Seismic Zone could be higher than associated with a major California Earthquake. In fact, according to USGS data, the anticipated ground motion which can result from an earthquake event triggered within the New Madrid Seismic Zone could be up to 17% greater than the anticipated ground motions in Los Angeles and up to 92% greater than anticipated ground motions in San Francisco for comparably significant earthquake events in those areas. But what is the likelihood of such an event happening? USGS reports indicate the chance of having a magnitude 6.7 or larger earthquake over the next 30 years is greater than 65% for Los Angeles and the chance of having a 6.0 or greater magnitude earthquake in the next 50 years within the New Madrid Zone is between 25 to 40 percent. And while a M6.0 earthquake in Memphis is smaller than the 6.7 considered for Los Angeles, it must be remembered that the capacity to resist such earthquakes is significantly less due to far less stringent building practices in the New Madrid region.
Haiti’s devastating earthquake highlights what could happen in Middle America near the vicinity of New Madrid, Missouri. Over 70% of the building inventory in Port-au-Prince collapsed, was significantly damaged or was deemed unusable for a considerable time. The majority of the affected buildings were unreinforced masonry buildings with and without nominally reinforced concrete frames. Middle America has a similarly high number of unreinforced masonry buildings which, while of slightly different vintage or construction practice, have equally low capacity to resist significant ground shaking. Pictures of downtown Port-au-Prince give vivid examples of what could happen to downtown Main Streets across the New Madrid region.
The Haiti earthquake also provides a view of the impact to society beyond the damage. The collapse of a significant number of schools in Haiti has placed a huge burden on the next generation. So many schools failed in the Port-au-Prince region that the national government suspended the school year for approximately 3 months nationwide, and while many schools outside of the immediate Port-au-Prince region are back to teaching, a significant number of students are still without classrooms in Haiti. As another example, in Chile, the extent of major damage to schools following its M9.0 earthquake three months after Haiti was less impactful; however, the loss of operations due to interior damage and disruption of contents still resulted in closed school buildings for months after the event. The disruption of their education will likely impact this generation of students well beyond the immediate recovery and rebuilding of these two nations.
Business Disruption Risks
Disruption or continuity of business can be just as critical to the recovery of a devastated region as is ability to protect and care for the injured. In Haiti, the garment industry is a major contributor to the national economy. It was imperative that the manufacturers were able to ensure their clients that the production of apparel was operational within days after the earthquake. Had a lengthy down-time ensued, clients likely would have shifted contracts to other providers in different nations, resulting in a critical loss to Haiti’s economic ability to respond and rebuild. It is reported that the massive damage to the port facilities in Kobe, Japan (1995 6.8M) caused much of that port’s shipping commerce to move elsewhere. One of the world’s busiest ports prior to the earthquake, Kobe has yet to regain its former status as Japan’s principal shipping port.
Firestorm and MHP, Inc. Structural Engineers continue to support our clients throughout the United States with preparedness planning and disaster response by participating in post-earthquake reconnaissance in Haiti, maintaining an extensive portfolio of seismic and risk assessment and mitigation experience, and developing continuity plans with clients to ensure better response before, during, and after a disruption or disaster. Preparations are underway for this year’s Great Central U.S. Shakeout (scheduled for February 7, 2012, at 10:15 a.m. CST, http://www.shakeout.org/centralus/). Regardless of your location, we encourage you to look to the Great Central U.S. Shakeout as a great opportunity to test your preparedness. More information on topics like this is forthcoming in our structurally-focused preparedness webinar series for 2012.
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