20-October-2023-Special-Article

WHY ARE EARTHQUAKES FREQUENT IN AFGHANISTAN?

Afghanistan experiences a high frequency of devastating earthquakes due to its location over active fault lines where tectonic plates frequently collide.

Recent earthquake events highlight the urgent need for understanding and managing seismic risks in the region.

How do Earthquakes Occur?

Tectonic Plate Movement: Earthquakes primarily occur due to the movement of Earth’s tectonic plates, which are massive sections of the Earth’s lithosphere. These plates are constantly shifting due to the heat energy generated within the Earth.

Fault Formation: Where these plates meet or interact, discontinuities called fault lines develop. This is where most earthquakes originate. Stress and strain accumulate along these fault lines.

Release of Energy: When the accumulated stress surpasses the strength of rocks, it’s suddenly released, causing rocks to break and slip. This abrupt release of energy generates seismic waves that propagate through the Earth, resulting in ground shaking and causing an earthquake.

Fault Plane and Epicentre: The point within the Earth where the rupture begins is the focus or hypocentre, while the point directly above it on the Earth’s surface is the epicenter.

Plate Boundaries: Earthquake-prone areas are usually located near plate boundaries, where tectonic activity is most pronounced, including subduction zones, transform boundaries, and divergent boundaries.

Tectonic Plate Interactions in Afghanistan

Plate Collision Zones

Afghanistan is situated at the convergence of the Indian and Eurasian tectonic plates, resulting in significant tectonic activity.

Collision Zones:

1. Western Afghanistan: Arabian plate subducts northward under Eurasia.
2. Eastern Afghanistan: Indian plate subducts northward under Eurasia.
3. Southern Afghanistan: Arabian and Indian plates adjoin and both subducts northward under Eurasian plate.

Geological Complexity

The presence of the Hindu Kush Mountain range and the Pamir Knot creates geological complexity at plate boundaries.

Convergence and Collisions: The Indian Plate collides with the Eurasian Plate, leading to crustal folding and faulting.

Compression and Stress

The northward movement of the Indian Plate toward the Eurasian Plate results in compression.

Uplift of the Himalayas and tectonic stress transmission create a seismic hotspot in Afghanistan.

Crustal Deformation: Compression causes deformation in the Earth’s crust, leading to fault formation and slip.

Active Fault Systems

Afghanistan is intersected by several active fault systems, including the Chaman Fault and the Main Pamir Thrust.

These faults are sources of numerous earthquakes in the region.

Conclusion

Afghanistan’s susceptibility to frequent earthquakes is primarily due to its geographical location overactive tectonic plate boundaries. Understanding these geological factors is essential for earthquake preparedness and risk reduction in the region.

Mains Question

1. Discuss the geological factors that make Afghanistan prone to frequent earthquakes. How can a better understanding of these factors aid in earthquake preparedness and risk reduction in the region? (150 Words)