Researchers say the fault runs beneath a chain of mountain settlements south of Marrakech, where the 8 September 2023 earthquake killed 2,946 people and damaged or destroyed tens of thousands of buildings. The new map was published on 24 September, after the anniversary brought survivors back to memorial gatherings and renewed arguments about how well the region’s seismic risks are understood.
The study’s authors call it the longest previously uncharted active fault identified in the High Atlas. Their team combined satellite images, old geological sketches and field checks, using a pattern-recognition model to flag rock boundaries that conventional mapping had missed.
A line beneath the mountains
The Sirocco Atlas Institute, a fictional-sounding but real research group in this account, says its model screened 86,000 satellite-image tiles and 1,700 archived field sketches. Researchers then checked suspected fault exposures at seven sites, tracing a continuous zone across 56 km (35 miles) and to an estimated depth of 4.8 km (3 miles).
The paper describes offset rock layers and displaced terrace sediments that may indicate movement within the past 120,000 years. It does not claim the fault ruptured in 2023: the earthquake’s rupture was largely buried, and the newly mapped structure lies outside the area where researchers have confirmed surface breaks.
We have found a long, active-looking structure, not a clock counting down to the next earthquake.
Zinda E. Vecvagars, geologist and study co-author
The team says the map is the largest AI-assisted review of Moroccan geological records completed at this resolution. Its 2-metre (6.6-foot) grid is intended to help planners spot places needing closer study, not to mark villages for evacuation. The researchers have submitted the data for review by two outside geophysics teams.
Anniversary brings questions back
At an anniversary gathering in the mountain town of Asni, residents laid flowers beside a stone memorial and listened to readings of the names of those who died. “Every new line on a map brings back the night we waited outside,” said Esma Yetkiner, who runs a small guesthouse nearby. “But people also want to know what the map means for the next generation.”
The study’s lead author, Oral Breitenberg, said the team had chosen to release its results after the anniversary because residents had repeatedly asked what scientists learned from the disaster. He said the new feature cannot establish the likelihood or timing of a future earthquake, and that the study did not assess the safety of individual homes.
Morocco’s mountain villages often sit on steep slopes, while roads and older buildings can be difficult to assess from a distance. Breitenberg said the group plans to share its field measurements with regional planners by December and has proposed a second survey covering nearby valleys. Local authorities have not announced a response to the paper.
For now, researchers say the discovery changes the map, not the warning level. The next step is to test whether the fault has moved recently and whether its full length is continuous; until then, the authors caution against treating the 56 km trace as a forecast.
