Aicha Coulibaly : “More studies will spring from this seism to thoroughly assess the region”

Aicha Coulibaly is a Geohazard Staff Professional with a background in seismology and a professional focus on pipeline geohazard assessment. She gives her viewpoint on the earthquake that occurred a few weeks ago in Morocco.

Al Haouz, the epicentre of the earthquake, was classified as having a very moderate seismic risk. Can we say today that every area of the country could be potentially seismic?

Earthquakes are results of fault ruptures that occur when there is plates collision, rifting, or sliding along each other. Al Haouz, located on the African plate, is on top of a fault zone caused by the heterogeneity of the direction of movement of the African plate.

Faults, either active or dormant, are a substantial ingredient to making an area seismically active. Areas located at fault zones are more prone to seismic activities while others are less likely to show current signs of seismic activities. Also depending on the magnitude of the earthquake and the depth, the mainshock and aftershocks can possibly affect other areas proximal to the epicenter.

The planet is constantly in movement and currently dormant fault zones could be reactivated due to (most likely) natural triggers or (rarely) anthropogenic triggers.

Though tragic this seismic event is, more studies will spring from it to thoroughly assess the region and provide deeper understanding of the subsurface.

Entire villages have been devastated by the earthquake. Many people are homeless. Is it safe to rebuild on these same sites today?

Countries like the United States of America and Japan have established a seismic building code for areas that are historically known for or prone to seismic activities. The areas impacted by the Al Haouz earthquake may require a thorough seismic assessment followed by a reevaluation and some modifications of the construction codes to reinforce infrastructures and mitigate future risks.

What measures do you think should be taken when building in areas known to be earthquake-prone?

It is very important to thoroughly assess any area for all potential hazards before, during, and after construction to mitigate the effects of geological hazards, or seismic hazards in our case here. When potential hazards are identified in the region, a mitigation plan is set up to address or circumvent the hazards using sophisticated engineering tools and methods. Subsequently, a geological hazards assessment is the first step that will define other necessary measures.

Today, many people are wondering whether such disasters can be anticipated to prevent and protect people in the future. What about earthquake prevention?

The first signs of earthquake could be recorded before any visible signs on the surface due to the first waves (compressional waves) traveling through the subsurface. These first waves do not create much destruction at the surface in comparison to the waves called surface waves, which comes after compressional and shear waves. Detecting the compressional waves could help warn about the potential of earthquakes that could happen in the following seconds.

The geological history of a region provides clues on the possibility of an earthquake to occur in the region. These are probabilities and not definite predictions. Furthermore, nature is its own boss, is very complex, and is constantly evolving. Therefore, predictions could help in substantially reducing risks and possibly avoid tragic outcomes. Growing scientific research and technology could foster significant advancements in earthquake predictions.

Interview by Danielle France Engolo