For Kids · The land and the sky · The ground under you
Gauteng · Highveld & Drakensberg · basalt country
Try it
Drag the spade down, or tap Dig deeper, through the leaves, the living topsoil and the subsoil, all the way to the bedrock that is really down there.
About 0 cm down
The grass
the top of the ground
Under the grass is a whole hidden world. Drag the spade down — or press Dig deeper — to find out what is down there.
Layer 0 of 5
It takes hundreds of years to make one centimetre of topsoil. The depths are typical — every place is different — and the ruler is squashed at the bottom so the rock fits on the screen.
Say it like this
Go outside: Dig a small hole in the garden and count how many worms live in one shovelful — then put them all back and fill it in.
The river right now
389%
of the ten-year median for this date · 1.1 m³/s against 0.3 normally
very highWell above normal. The river is moving gravel and wood, the banks are undercut and unreliable, and this is the state in which people drown. Watch it from the bank. It is rising — about 429% more water by the end of the week.
Under your feet
About 2.5 billion years old — laid down before anything with a shell or a backbone existed.
All the kinds of rock, and how each one forms →
Paleoproterozoic sedimentary and volcanic rocks · Siderian
· Mesoarchean
volcanic-sedimentary · Mesoarchean
Bedrock and soil figures are modelled from national geological surveys and global soil mapping, at a resolution of a few hundred metres — right for the shape of a district, not for a particular garden. River discharge is modelled, not gauged. For anything that matters, dig a hole and look.
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Try it
Drag the spade down, or tap Dig deeper, through the leaves, the living topsoil and the subsoil, all the way to the bedrock that is really down there.
About 0 cm down
The grass
the top of the ground
Under the grass is a whole hidden world. Drag the spade down — or press Dig deeper — to find out what is down there.
Layer 0 of 5
It takes hundreds of years to make one centimetre of topsoil. The depths are typical — every place is different — and the ruler is squashed at the bottom so the rock fits on the screen.
Say it like this
Go outside: Dig a small hole in the garden and count how many worms live in one shovelful — then put them all back and fill it in.