Context: The Palghat Gap in the Western Ghats is a significant break in the mountain range, measuring about 40 km wide.
About the Gap:
Information
Details
Surrounding hills
It is characterized by the steep Nilgiris and Anamalai hills on either side, both rising above 2,000 meters above sea level.
Importance
Gateway into the State of Kerala for roads and railways
River flowing through it
Bharathappuzha river
Vegetation
Unlike the tropical rainforests found in other parts of the Western Ghats, the vegetation in the Palghat Gap is classified as dry evergreen forest.
Shear Zone
Geologically, the Palghat Gap is a shear zone running from east to west.
Shear zones are weak regions in the Earth’s crust, which occasionally result in tremors felt in the Coimbatore region.
Origin
The origin of the Gap can be traced back to the separation of Australia and Africa from the Gondwana landmass, causing continental drift.
Biogeographic distinctions
Several species of flora and fauna are found only on one side of the Gap. Also, the Mitochondrial DNA of elephants on the Nilgiris side differ from those in Anamalai and Periyar sanctuaries
Rainfall
The Western Ghats north of the Palghat Gap receive more annual rainfall, but the south experiences rainfall more evenly distributed throughout the year.
Biodiversity South of the Gap
Abundant species richness and diversity.
Reason: The warm weather, evenly distributed rainfall, proximity to the equator, and moist air
Other gaps
Thal Ghat Pass (Kasara Ghat) (connects Mumbai to Nashik); Bhor Ghat Pass (connects Mumbai to Pune via Khopoli); Amba Ghat Pass (connects: Ratnagiri district to Kolhapur); Naneghat Pass (connects Pune district with Junnar city); Amboli Ghat Pass (connects Sawantwadi of Maharashtra to Belgaum of Karnataka)