Atlas Mountains: A Brief Overview
The Atlas Mountains, which extend mainly through Morocco, Algeria and Tunisia, are an important range in north-west Africa. They stand as witness to the constantly changing dynamics between the Eurasian and African (Nubia) tectonic plates. Although seismic activity is low here compared to other tectonic boundaries, historical events such as the 1960 Agadir earthquake are painful reminders of the region's potential seismic power.
Understanding the Geology of the Atlas Mountains
A distinguished consortium of geologists, geophysicists and geodesists from several Moroccan and Spanish institutions have tirelessly dedicated their expertise to unraveling the secrets hidden within these mountains. Their objective is to understand the evolution of the Atlas Range and its interesting position at the edge of the continental plate boundary. Various methods, including seismic activity studies and gravity measurements, provide insight into the Earth's deep structure, diving to depths greater than 100 km.
Field geological expeditions enable the detection and analysis of cracks in the Earth's crust. These faults manifest themselves as manifestations of horizontal, vertical or diagonal movements. Such movements are induced due to the enormous forces acting on the Earth's tectonic plates.
A Journey Through Time: The Formation of the Atlas Mountains
Evidence suggests that the Atlas Mountains were created during the breakup of the Pangea supercontinent. Their active height is evidenced by towering peaks and steep slopes. Interestingly, the sheer slopes and pronounced cracks in the earth's crust indicate recent underground movements. It is a puzzle that seismic activities are not more intense here.
From year to year, the mountains see shrinkage at the rate of about 1 millimetre. This is due to the Eurasian and African plates coming closer together. The region's highest peaks form at the southern edge of the convergence of these giant plates.
Reading between the seismic lines: the origins of recent earthquakes
The devastating earthquake occurred in the northern region of the Western Atlas Mountains and in the southern region of Marrakesh, at a depth of between 8 km and 26 km. It was born from a "reverse fault", a phenomenon that occurs when tectonic plates collide and cause the Earth's crust to condense. When such geological activities trigger earthquakes, rocks suddenly adjust to release buried stress, which marks a seismic fault.
The magnitude of 6.8 implies that a fault, approximately 30 km long, was responsible for this seismic event. This magnitude-fault length relationship provides invaluable data for understanding seismic dynamics.
Still, a burning question remains: Why are earthquakes an anomaly in a region marked by tectonic activity and rising mountains? Gaps in recorded seismic activity indicate underground accumulation of stress over long periods of time. The inability of the fault to withstand this stress resulted in the recent earthquake.
Preparing for the Future: A Seismic Blueprint
Although predicting earthquakes remains a challenge, strategies to mitigate their impacts are indispensable. A holistic approach incorporating geological, geophysical and geodetic research of the area can pinpoint active seismic faults. These insights are paramount to predicting the frequency and intensity of potential earthquakes. Recognizing faults capable of producing powerful earthquakes after long periods of inactivity is important for future seismological studies.
To reduce earthquake damage, it is important to adopt stringent seismic building design codes. By strengthening structures to withstand maximum seismic activity, destruction can be reduced. Furthermore, strengthening traditional habitations in hill settlements is important for avoidable disasters. Potential constructions must conform to evolving seismic building standards, ensuring both economic feasibility and strength.
The Atlas Mountains, with their rich geological tapestry, provide invaluable insights into the dynamic processes of our planet. As we continue to explore, understand, and respect these ancient ranges, it is important to arm ourselves with the knowledge and preparedness to ensure the safety and prosperity of the people who live in their shadow.