Maps and place knowledge

The easting

HintGo along the corridor before you go up the stairs.

The whyEastings are the numbers that increase from left to right across the map; northings increase up it. A four-figure reference names one grid square, a kilometre across.

Six

HintAdd one more digit to each half of a four-figure reference.

The whyA four-figure reference names a whole 1 km square. Adding an extra digit to each half splits that square into tenths, so the reference locates you to within 100 m.

1 kilometre

HintWork out what a single centimetre is worth first, then double it.

The whyA scale of 1:50 000 means 1 cm on paper stands for 50 000 cm on the ground, which is 500 m. Two centimetres is therefore 1000 m. Most OS Landranger maps use this scale.

steep

HintThe lines are squeezed because you gain a lot of height over very little ground.

The whyEach contour joins points of equal height, so lines close together mean a big height change across a short distance. Widely spaced contours mean gentle, easy walking.

The Pacific Ocean

HintIt sits between Asia and the Americas, and its name means peaceful.

The whyIt covers about a third of the planet - wider than every landmass put together. The five oceans are the Pacific, Atlantic, Indian, Southern and Arctic.

0 degrees

HintIt is the starting line from which every other parallel is counted north or south.

The whyLatitude is measured outwards from the Equator, so the poles sit at 90° north and 90° south. Longitude is measured the same way from the Prime Meridian at Greenwich.

Wales

HintThe country immediately west of England, with Snowdonia in its north.

The whyThe four capitals are London for England, Edinburgh for Scotland, Cardiff for Wales and Belfast for Northern Ireland. Cardiff stands on the Bristol Channel in the south.

The mantle

HintThe thick, slowly creeping layer that carries the plates on its back.

The whyIt is by far the thickest layer, made of hot rock that flows a few centimetres a year. Convection currents within it are what drag the plates about.

A constructive boundary

HintNew rock rises to fill the gap, so land is being made rather than destroyed.

The whyAt a constructive (divergent) boundary such as the Mid-Atlantic Ridge, magma rises into the gap and cools into fresh crust. Iceland is being widened by one right now.

The Sahara

HintIts name is simply the Arabic word for desert.

The whyIt is the largest hot desert on Earth, roughly the size of the United States. South of it lies the dry grassland of the Sahel, and further south again the Congo rainforest.

The Himalayas

HintIt holds Everest and separates the subcontinent from Tibet.

The whyThe range was thrown up where the Indian plate crashed into Asia, and it is still rising. It blocks cold northern air and shapes the monsoon that waters India.

Russia

HintIt spans eleven time zones, from the Baltic to the Pacific.

The whyIt covers about an eighth of the world's land, though much of that is Siberian forest and tundra. Most of its people live in the European west, near Moscow and St Petersburg.