NCERT Solutions for Class 9th Social Science Chapter 2 Does India have a risk of earthquakes? (Fig. 2.5) — LET'S EXPLORE

Book page 17 Updated on2026-09-08

Q1.

Can you find out which region is more vulnerable to earthquakes?

Answer

Yes — the Himalayan belt in the north and north-east is India's most vulnerable region, followed by the Kachchh region of Gujarat and the Andaman and Nicobar Islands.

The reasoning, from the maps in this chapter:

Fig. 2.3 shows the arrows on the Indo-Australian plate pointing north into the Eurasian plate. That collision has not stopped — it is what raised the Himalaya and it is still going on.
Fig. 2.4 confirms it independently: a continuous line of earthquake origins runs along the Himalayan arc, from Jammu and Kashmir through Himachal Pradesh, Uttarakhand, Nepal, Sikkim and the north-eastern states, and continues down through the Andaman Islands into Indonesia.
Fig. 2.5 gives a worked example of the damage — the Gujarat earthquake of 2001, in the Kachchh region, far from the Himalaya but on an active fault zone within the plate.

Ranking the regions by risk:

Region	Why it is at risk
The Himalayan belt and the north-east	Sits directly on the convergent boundary where the Indo-Australian plate is pushing under the Eurasian plate — the highest risk in the country
Kachchh, Gujarat	An active fault zone inside the plate; the source of the 2001 earthquake shown in Fig. 2.5
Andaman and Nicobar Islands	On the same plate boundary as it curves south into Indonesia
The Indo-Gangetic plain	Close to the Himalayan source, and its thick soft alluvium shakes far more strongly than hard rock does
The peninsular shield (most of central and south India)	Old, stable crust in the middle of the plate — the lowest risk, though not zero

Try this: place a piece of tracing paper over the earthquake map in Fig. 2.4, mark only the dots that fall on India, then compare your tracing with a physical map of India. The line of dots will lie along the Himalaya — the mountains and the earthquakes have the same cause.

Q2.

Why do you think human lives are at risk?

Answer

Because, as the box says, India is a densely populated country — so a single large earthquake reaches an enormous number of people at once. Past earthquakes here have already killed thousands.

The reasons, in order of importance:

Population density. The Indo-Gangetic plain, close to the Himalayan source, is one of the most crowded regions on Earth. The same shaking that would harm a few hundred people in an empty region can reach millions here.
It is buildings that kill, not the shaking itself. Fig. 2.5 shows exactly this — the ground is not torn open; what covers the ground is the rubble of collapsed buildings. Heavy unreinforced masonry, unplanned multi-storey construction and poor foundations turn a tremor into a burial.
Soft ground amplifies the shaking. The plains are built of thick river alluvium, which shakes much more violently than solid rock, so damage extends far from the source.
Earthquakes cannot be predicted. There is no warning, so people are indoors and asleep when it strikes.
Secondary effects follow. Landslides on Himalayan slopes, blocked roads, broken water and power lines, and fires prolong the disaster long after the shaking stops. Damage to the environment — the box's own words — comes with the damage to life.

The idea behind all of this: risk is not the hazard alone. Risk = hazard (how strong and how likely the earthquake is) × exposure (how many people and buildings are there) × vulnerability (how badly they are built). India cannot change the first — the plates will keep moving — but it can change the third, which is why earthquake-resistant building codes save more lives than anything else.

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