Download Shaping of the Earth’s Surface – NCERT Class 9 Social Science Chapter 2 PDF from the new NCERT Class 9 Social Science book Understanding Society: India and Beyond (2026-27). Read the chapter online or download the free PDF. The Earth has three main layers — crust, mantle and core. The crust together with the upper mantle makes the rigid lithosphere (about 100 km thick in Fig. 2.1); below it lies the hot, partly molten asthenosphere (about 200 km), which is what lets…
Shaping of the Earth’s Surface PDF – Chapter 2 of Understanding Society: India and Beyond (Part I)
Read the chapter online or download the PDF.
| Chapter | Download | |
|---|---|---|
| Chapter 2 PDF | Shaping of the Earth’s Surface | View PDF |
| Full book | NCERT Class 9 Social Science – Understanding Society: India and Beyond | View Book |
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What Is in Shaping of the Earth’s Surface? (Class 9 Social Science Chapter 2)
- The Earth has three main layers — crust, mantle and core. The crust together with the upper mantle makes the rigid lithosphere (about 100 km thick in Fig. 2.1); below it lies the hot, partly molten asthenosphere (about 200 km), which is what lets the plates move at all.
- The lithosphere is broken into tectonic plates — continental, oceanic and mixed — that creep along at a few centimetres a year. Fig. 2.3 names seven major plates: Pacific, Eurasian, African, North American, South American, Indo-Australian and Antarctic.
- Plates move because of convection currents in the mantle: heated material rises, cooler material sinks, and the circulating mantle pushes and pulls the plates. Fig. 2.2 splits the total interior heat flow between crust (24%), upper mantle (22%), lower mantle (32%) and core (22%), and shows it travelling outward by advection, convection and conduction.
- The three plate boundaries explain where the big landforms sit — convergent (fold mountains such as the Himalaya; volcanoes and earthquakes where an oceanic plate sinks under a continental one), divergent (new crust and mid-ocean ridges such as the Mid-Atlantic Ridge) and transform (earthquakes such as along the San Andreas Fault). Comparing Fig. 2.3 with Fig. 2.4 shows earthquakes and volcanoes tracing the boundaries, above all the Ring of Fire.
- External forces then carve the raised land. Weathering breaks rock in place (physical, chemical, biological); erosion also carries the broken material away. The agents of gradation — running water, glaciers, wind, waves and groundwater — lower the high ground and fill the hollows, and each leaves its own family of landforms: waterfalls, meanders, oxbow lakes and deltas (rivers); beaches, sea cliffs, caves, arches and stacks (waves); U-shaped valleys, cirques, aretes, fjords and moraines (glaciers); yardangs, ventifacts, deflation hollows and dunes (wind); caves, stalactites, stalagmites and sinkholes — Karst topography (groundwater).
- Landforms shape human life, and their hazards too: landslides, avalanches, GLOFs and dust storms, along with the earthquakes and eruptions of plate boundaries — the Chamoli flood of February 2021 and the Gujarat earthquake of 2001 are the chapter’s own examples.
Quick revision – Shaping of the Earth’s Surface
| Term | What it means | Where it appears in the chapter | Example from the book |
|---|---|---|---|
| Lithosphere | The rigid outer layer of the Earth — the crust plus the upper mantle. It is this layer that is broken into plates. | Page 14, Fig. 2.1 | Shown as about 100 km thick in Fig. 2.1 |
| Asthenosphere | A hot, mobile layer of partially molten rock below the lithosphere. Because it can flow, the plates above it can move. | Page 14, Fig. 2.1 | Shown as about 200 km thick in Fig. 2.1 |
| Tectonic plate | A massive slab of solid rock that carries continents (continental), ocean floor (oceanic) or both (mixed), moving a few centimetres a year. | Pages 13–15, Fig. 2.3 | Indo-Australian Plate, Pacific Plate, Eurasian Plate |
| Convection current | The circulation set up in the mantle when hot material rises and cooler material sinks. It pushes and pulls the plates. | Page 15, Fig. 2.2 | Fig. 2.2 shows the loops, and magma zones under the crust |
| Convergent boundary | Where two plates move towards each other — crust is crumpled or destroyed. | Page 15 | The Himalaya, formed by colliding continental plates |
| Divergent boundary | Where two plates move apart; magma rises into the gap and makes new crust. | Page 15 | The Mid-Atlantic Ridge |
| Transform boundary | Where two plates slide past each other; no crust is made or destroyed, so earthquakes dominate. | Page 15 | The San Andreas Fault, United States |
| Ring of Fire | The belt around the Pacific Ocean where most of the world’s earthquakes and volcanoes occur. | Page 16, Figs. 2.3 and 2.4 | The dense band of dots and triangles rimming the Pacific in Fig. 2.4 |
| Weathering | The breaking down of rock where it lies — physical, chemical or biological. The broken material does not move. | Pages 19–20, Fig. 2.8 | Plant roots growing into cracks and splitting a rock |
| Erosion | Wearing away and carrying away of soil and rock by water, wind, ice or waves. | Page 20, Fig. 2.9 | Gullies cut by running water; soil lifted by wind |
| Agents of gradation | The natural forces that wear down, transport and deposit material, levelling the surface over time. | Pages 21–22 | Running water, glaciers, wind, waves, groundwater |
| Karst topography | The landscape made where underground water dissolves limestone and other soluble rock. | Pages 31–32, Figs. 2.24–2.26 | Caves, stalactites, stalagmites, sinkholes, underground rivers |
Old NCERT vs New – Class 9 Social Science
This chapter is from Understanding Society: India and Beyond, the new NCERT Class 9 Social Science book (NCF-SE 2023, used from 2026-27). It replaced the old book “India and the Contemporary World, Contemporary India, Democratic Politics and Economics”, so chapter numbers and names differ from older PDFs.
Solutions and All Chapters
Answers to the exercises and the full chapter list of Understanding Society: India and Beyond:
Shaping of the Earth’s Surface – Overview
| Class | Class 9 |
| Subject | Social Science |
| Book | Understanding Society: India and Beyond – new NCERT book |
| Part | Part I |
| Chapter | 2 of 15 – Shaping of the Earth’s Surface |
| Book pages | 13 – 38 |
| Edition | Latest NCERT edition (2026-27) |
| Session | 2026-27 |
| Free – read online or download |
Class 9 Social Science Chapter 2 – FAQs
Where can I download Shaping of the Earth’s Surface Class 9 PDF?
From the download table on this page – the chapter PDF is free, and the full book is linked too.
What is Class 9 Social Science Chapter 2 about?
The Earth has three main layers — crust, mantle and core. The crust together with the upper mantle makes the rigid lithosphere (about 100 km thick in Fig. 2.1); below it lies the hot, partly molten asthenosphere (about 200 km), which is what lets the plates move at all.
Is Shaping of the Earth’s Surface from the new NCERT Class 9 Social Science book?
Yes. It is chapter 2 of understanding society: india and beyond (part i), the new NCERT Class 9 Social Science book for 2026-27.
Is this the latest NCERT edition for 2026-27?
Yes – the PDF is NCERT’s latest edition for the 2026-27 session.
Where are the NCERT Solutions for Class 9 Social Science Chapter 2?
Open the NCERT Solutions link above for answers to the exercise questions.