How do Haiti earthquakes compare? Experts hope for less damage, death than in 2010
Haiti on Saturday was struck by a powerful earthquake that by one measure was actually stronger than the devastating 2010 quake that turned much of the capital city of Port-au-Prince into rubble.
The 7.2 magnitude earthquake has killed at least 225 people, an early toll that experts fear will rise dramatically in coming days. However, experts don’t think the damage will be as widespread or deadly as in 2010, when a 7.0 earthquake killed more than 300,000 people and destroyed the homes of 1.5 million people.
There are several reasons why.
Florida International University Professor Grenville Draper, a geologist who was involved in the study and mapping of the fault that caused the 2010 earthquake, says part of it has to do with where the quake occurred. Haiti has two prominent fault zones and both quakes happened over the Enriquillo-Plantain Garden fault zone.
But Saturday’s earthquake happened in Haiti’s southwest Tiburon peninsula, in a more rural area of the country, about 60 miles west of where the 2010 earthquake happened near Port-au-Prince, which is the most heavily populated area in the country.
The other reason is because structural damage is determined mostly by intensity, not magnitude, said Lucy Jones, a seismologist and founder of the Dr. Lucy Jones Center for Science & Society, who was tweeting information about the quake Saturday.
Magnitude measures the total energy released in the earthquake while intensity measures the shaking people feel, which can vary depending on where they are. An earthquake with an intensity of 2, for example, is something you would feel if you were lying in bed while an intensity 4 is when you might notice rattling teacups in the kitchen, Draper said. Intensity 7 can cause building damage.
The United States Geological Survey said the perceived shaking for Saturday’s earthquake ranged from “very strong to severe and weak to light in Port-au-Prince.”
“From location, magnitude and intensity of a quake, we estimate the distribution of strong shaking. @USGS maps that against population distribution to estimate losses. Today’s M7.2 Haiti quake gave 130k people Intensity VII shaking, so losses will be high,” Jones said on Twitter.
However, she said the damage should be less severe because Port-au-Prince was spared the worst of the quake, feeling an intensity of about 5. In 2010, the intensity hit 7 in the capital, the most heavily developed and populated area in the country.
“They should have gotten scary shaking today, Intensity V, but only really bad buildings would be damaged — and most of those were destroyed in 2010,” Jones said on Twitter.
Reginald Desroches, an earthquake expert who traveled to Haiti after the 2010 quake and currently serves as provost of Rice University, said experts will verify the exact magnitude once they find the fault line, narrowing it down from a current reported range of 6.9 to 7.2.
“It’s comparable, if not bigger than the previous one. It’s more shallow, which means it’s going to produce more shaking. The saving grace is that the area is not as populated as Port-au-Prince,” he said. “I imagine the structures are poorly built because it’s a more rural area, so that’s the thing we are dealing with — on a percentage basis we could be dealing with even more damage even though there aren’t as many people in those areas.”
Desroches, who is of Haitian descent, said that some expected the next big one to occur in the northern part of the country because of geological stresses that have built up but Saturday’s event underscored another reality of earthquakes.
“This is what they do. These are unusual phenomenons and you just never know where it’s going to happen,” he said.
Claude Prepetit, Haiti’s chief seismologist, also thinks the damage won’t be as widespread as the 2010 quake, but warns aftershocks could still topple buildings.
”This is why we are asking people not to run back into buildings,” he warned. “Wait on the evaluations.”
Miami Herald staff writers Jacqueline Charles and Syra Ortiz-Blanes contributed to this report.
This story was originally published August 14, 2021 at 5:13 PM.
