Why in the News?
Recent studies reveal that the Indian Plate is splitting into two, with the lower part detaching and sinking into the Earth’s mantle, a process called delamination, as published by the American Geophysical Union.
About Delamination:
- Delamination in tectonic plates refers to the process where the lower part of a continental plate, including the lower crust and/or lithospheric mantle, splits and sinks into the Asthenosphere.
- This process is driven by density differences and can lead to rapid uplift, changes in stress regimes, and altered magmatism.
- It can occur in various tectonic settings, including compressional zones, subduction zones, and intraplate regions.
- The denser lower part of the plate, including the lower crust and/or lithospheric mantle, is less buoyant than the less dense asthenosphere, leading to sinking.
- High temperatures can also weaken the lithosphere and facilitate delamination.
Indian Plate and Its Splitting:
- The Indian Plate has been colliding with the Eurasian Plate for about 60 million years, causing the formation of the Himalayas and influencing regional seismic activity.
- It is shifting northward at a rate of approximately 5 cm per year..
- The lower, denser part of the Indian Plate is detaching and sinking into the Earth’s mantle.
- This may lead to increased seismic activity due to shifts in tectonic stress.
- In regions like the Himalayan collision zone, delamination results in fractures that increase stress in the Earth’s crust, raising the likelihood of seismic events.
| [UPSC 2004] Consider the following geological phenomena:
1. Development of a fault 2. Movement along a fault 3. Impact produced by a volcanic eruption 4. Folding of rocks Which of the above cause earthquakes? Options: (a) 1, 2 and 3 (b) 2 and 4 (c) 1, 3 and 4 (d) 1, 2, 3 and 4 |
