---
title: "Why the Himalaya is vulnerable"
subject: "Engineering Geology II"
chapter: 2
key: "semester_4/engineering_geology_ii:why-himalaya-vulnerable"
source: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/why-himalaya-vulnerable
site: BCT Engineering
---

# Why the Himalaya is vulnerable

Engineering Geology II · Chapter 2: Engineering Geology in Himalayas

- Asked in: 2079 Chaitra, 1 marks
- Video: [The Great Himalayan Earthquake: A Mega Disaster Waiting To Strike!](https://www.youtube.com/watch?v=woxOcrxhNiE) — Earthly
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/why-himalaya-vulnerable
- Whole chapter: https://www.bctengineer.com/md/semester_4/engineering_geology_ii/chapter-2

## Question

Why are the Himalayas so vulnerable?

## Short answer

Young, tectonically active mountains with continuing plate collision (4-5 cm/yr), highly folded/fractured rocks, steep slopes, intense monsoon rainfall, weak rocks, frequent earthquakes, glacier melting, deforestation, and unplanned construction.

## Answer

The Himalaya is vulnerable to geological hazards because:
- It is a **young, tectonically active mountain** formed by the continuing collision of the Indian and Eurasian plates; India moves north by about 4-5 cm per year.
- Rocks are highly **folded, faulted and fractured**, with active thrusts such as MFT, MBT and MCT.
- **Very steep slopes** and high relief give high gravitational energy.
- **Intense monsoon rainfall** saturates slopes and increases erosion.
- Many rocks are **weak** (phyllite, schist, Siwalik mudstone).
- Frequent **earthquakes**, glacier melting and deforestation add to the instability.
- Rapid, unplanned road construction and human settlement increase the risk.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Why is the Himalaya tectonically active?
   A. Continuing collision of Indian and Eurasian plates
   B. Volcanoes only
   C. Ocean tides
   D. Human mining only
   Answer: A. India moves north about 4-5 cm per year, keeping the range young and active. (Key point: Tectonic origin)

2. How does intense monsoon rainfall add to vulnerability?
   A. It dries slopes
   B. It saturates slopes and increases erosion
   C. It strengthens rocks
   D. It stops earthquakes
   Answer: B. Saturation reduces slope stability and raises erosion. (Key point: Rainfall)

3. Which rock condition makes the Himalaya vulnerable?
   A. Massive unjointed granite everywhere
   B. Folded, faulted, fractured and weak rocks like phyllite and Siwalik mudstone
   C. Only limestone
   D. Only alluvium
   Answer: B. Intense folding, faulting and weak rocks reduce stability. (Key point: Rock condition)