Physical Geography: Earth & Landforms
Physical geography rewards understanding why rather than memorising lists. If you know that the Earth's tilt is 23.5° and that it causes the seasons, you can reason out solstices, equinoxes and day length instead of recalling them separately.
Don't read this page — work through it. Each block asks you to commit to an answer before it tells you anything.
Start here: what do you already know?
Physical geography — true or false?
6 statements · 12s each
The Earth's structure
| Layer | Roughly | Note |
|---|---|---|
| Crust | 5–70 km | Thinnest; oceanic crust is thinner than continental |
| Mantle | ~2,900 km | Thickest layer; source of magma |
| Outer core | ~2,200 km | Liquid; generates the magnetic field |
| Inner core | ~1,250 km | Solid, mostly iron and nickel |
The lines that matter
- Equator — 0°, divides north from south
- Tropic of Cancer — 23.5° North (passes through India)
- Tropic of Capricorn — 23.5° South
- Arctic Circle — 66.5° North
- Prime Meridian — 0° longitude, through Greenwich
The tilt of 23.5° is why the tropics sit exactly where they do — the same number appears in both places, which is the point worth noticing.
Sort by layer
Which part of the Earth is described?
0/6The thickest layer
Which group does it belong to?
Fix the numbers
Commit, then check
1/4What is the Earth's axial tilt, in degrees?
25°
Method, in order
Match the term to its meaning
Quick reference
Exam tip: the number 23.5 appears three times — the axial tilt, the Tropic of Cancer and the Tropic of Capricorn. They are the same number because the tilt is what places the tropics. Understand that link and you stop needing to memorise them separately.