Geography · Rung 6 of 12

Mountains and plains

Relief is drawn by plate tectonics. Where two continental plates collide you get a mountain range with no volcanoes, like the Himalaya, still rising a few millimetres a year; where an oceanic plate dives under a continental one you get a range with volcanoes and earthquakes, like the Andes; where two pull apart you get a mid-ocean ridge, and on land a Rift valley. The earthquake belts on the map are exactly the plate edges, and the Ring of Fire circles the Pacific. Hotspots are the exception: Hawaii is not on an edge, it sits over a fixed plume in the mantle and the plate slides over it, leaving a line of islands that get older along the way.

Where this sits

Comes after
The map and its signs
Opens up
Climates and biomes, Reading a real map

Exercises from this rung

Generated by the app, from easiest to hardest

  1. A 900 km west-east cross-section rising from the sea to 4,400 m. Which range is it?

    • The Andes
    • The Himalaya
    • The Alps
    • The Urals

    Why Two clues give it away: it starts at sea level and climbs very fast (the Andes drop straight into the Pacific) and it reaches 4,400 m, too much for the Urals and for the Alps across so wide a section. The Himalaya would be higher and would end on the Tibetan plateau at 4,500 m instead of dropping to the plain.

    easier

  2. Put these peaks in order, highest first.

    Answer Everest, Aconcagua, Denali, Puncak Jaya

    Why The order is: Everest (8,849 m), Aconcagua (6,961 m), Denali (6,190 m), Puncak Jaya (4,884 m).

    in between

  3. This cross-section does not rise to a peak: it stays high and flat for hundreds of kilometres. What landform is it?

    • A plateau
    • An alluvial plain
    • A young mountain range
    • A glacial valley

    Why A plateau is a raised, roughly flat surface, and on a profile you recognise it because the line climbs once and stays up instead of making peaks. Spain's Meseta Central averages about 650 m and covers 40 % of the country; the Bolivian Altiplano sits around 3,800 m. Young ranges, by contrast, give sawtooth profiles.

    harder