A resort on Haiti. Photo: Junior Ceranor Nelson, pexels.com
We hopefully all know by now that we live on a very active planet. According to the United States Geological Survey, records suggest that we can expect around 16 major earthquakes in any given year – roughly 15 earthquakes within the magnitude 7 range and one magnitude 8.0 or greater. In 2010 there were 23 earthquakes of M7.0 or greater. One of those devastated Haiti on January 12.
Janine Krippner
Just reporting a magnitude is only part of the story; depth of the rupture is important as that strongly influences intensity felt at the surface. Is it just 13 km below the surface like the Haiti earthquake? Or 107 km depth like the one I felt in Wellington a couple of weeks ago.
Then there is location: how close is it to population centres and critical infrastructure? The fault that ruptured in 2010 was close to Port-au-Prince, Haiti’s capital.
Next, are those population centres prepared with funding and efforts put into earthquake safe housing and infrastructure? Or are they already in a vulnerable situation? Unfortunately, Haiti was, and still is, the latter category and the consequences were catastrophic. The numbers vary but all are staggering, with estimates of around 316,000 dead or missing, 300,0001 injured, and over 1.3 million homeless. One of the most destructive modern earthquakes, globally.
Housing loss was immense, with an estimated 300,000-plus homes collapsed or critically damaged. Roads and other lifelines were impacted, making response more difficult.
Port-au-Prince, Ouest Department, Haiti. Photo: Matteo Favre, pexels.com
The buildings themselves can put a population at greater risk. Prior to the event there was a lack of seismic building codes and building materials, consisting largely of poor-quality, reinforced but lower strength concrete (compared to the USA for example), that does not flex during earthquake shaking.
Work done to prepare for an event itself, and for the aftermath, is critical, but they do not create immediate or flashy results. This may make it seem less of a pressing issue. Haiti is a heartbreaking example of how disaster risk is shaped not only by geology, but also by vulnerability and capacity, and why preparedness cannot be allowed to fade into the background. When it does, the result can be utterly devastating.
Geologically, Haiti sits on the boundary region between the Caribbean plate and the North American plate, and the 2010 earthquake was caused by shallow strike-slip faulting where two sides of a fault move sideways past each other.
Their vulnerability is also shaped by a traumatic history of slavery and harmful financial reparations for their freedom, which still very much ripple into their current struggles. Our histories and current social makeup influence how we can respond, and therefore, how we come out the other end.
When I hear of a large magnitude earthquake hitting the news, these are all the thoughts that go through my head. How deep? How close to people and infrastructure? And how prepared are those communities? The faulting style (e.g., strike-slip or subduction zone earthquake) whether it occurs on land vs under the ocean (tsunami risk) are some of the other aspects that influence impacts.
A simple earthquake magnitude is a great headline grabber, but it only tells a fraction of a story.
A resort on Haiti. Photo: Junior Ceranor Nelson, pexels.com
