a-new-tectonically-active-zone-in-himalayas-has-been-found

Context: The Indus Suture Zone (ISZ) in the Ladakh region where Indian and Asian Plates are joined has been found to be tectonically active, as against current understanding that it is a locked zone.

More on the news: A group of Scientists from Wadia Institute of Himalayan Geology (WIHG), Dehradun (autonomous institute under the Department of Science and Technology), have found the active zone through observations and detailed mapping of geological features.

The new findings:

  • Himalaya were known to be made up of north dipping thrusts like the 
    • Main Central Thrust (MCT), 
    • Main Boundary Thrust (MBT), and
    • Main Frontal Thrust (MFT). 
  • Earlier: As per the established models, all of these thrusts except MFT are locked, and overall deformation in Himalaya is being accommodated only along with the MFT. 
  • The new findings: Suggest a more remote fault at the suture zone being neo-tectonically active. 

Implications: 

  • This could have major implications in terms of earthquake study, prediction, understanding the seismic structure of the mountain chains well as its evolution.
  • This could call for a serious relook into the existing evolutionary models using new techniques and a larger geological database.

Correlation between plate tectonics and earthquakes:

  • An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth‘s lithosphere that creates seismic waves. 
  • Plate tectonics: The earth’s lithosphere is composed of seven major plates and many minor plates. 
    • Plate tectonics is a scientific theory describing the large-scale motion of these minor and major plates. 
    • Plate motions create plate boundaries and each dynamic activity of earth is developed at plate boundaries including earthquakes.
  • Distribution of earthquake along plate boundaries:
    • Divergent Plate boundary: This happens when two plates move away from each other. Due to this, the energy from beneath finds a way to come out striking earthquakes along the rift. This creates shallow focus earthquakes. For example, mid-Atlantic ridge

 

Image source: wikipedia

  • Convergent plate boundary: When two plates collide, the impact leads to violent shaking and results in powerful and deep focus earthquakes. For example, Himalayas, Andes.

Image source: wikipedia

  • Transform plate boundary: Plates slide past each other. Due to this rocks rub against each other creating fracture. This is the site of an intermediate focus earthquake. For example, San Andreas fault.

Significance of plate tectonics:

  • Even though earthquakes are disasters for mankind but incidence of earthquakes beneath the oceans helps to understand seafloor expansion with respect to plate tectonics. 
  • Also, concentration of earthquakes in particular zones helps us to identify the nature, speed and direction of plate. 
  • This holds huge significance in the form of plate boundaries.