Ice, powder and hardpack

Three surfaces

The snow under the board is never just snow. Every point on the mountain carries two weights, ice and powder, laid out by two independent noise fields; where neither is strong you are on hardpack, which is the baseline everything else is measured against. Ice wins where the bands overlap — a frozen patch cannot also be bottomless fluff — so the two never blend into a third thing.

You can see all three. Ice is glossy: it reflects the sky, which is what makes it readable in motion long before you reach it, and it tints toward a dark steel blue. Powder is warm and lumpy — pillowed with soft relief, because colour alone flattens out under the lighting. Hardpack is the bright, textured white in between.

What ice does

• Grip drops by two thirds. The carve force that bends your line is cut to 32% of normal on full ice. You do not turn; you drift, wide, and the board slides sideways across the fall line while you hold the edge.
• It is fast. Sliding friction falls to 30%, so ice carries speed a hardpack traverse would bleed.
• Stopping takes room. A hockey stop's edge holds about two thirds as hard on ice, so the stop turns into a long slide, roughly twice the distance. Plan it before the patch.
• It throws a skid. Steering on ice produces visible side-slip — the powder spray you see is the edge letting go.
• Landings get no help. Nothing softens a landing on ice.

The tactical answer is line choice: cross ice straight, carry the speed, and do the turning either side of it.

What powder does

• It ploughs. Aerodynamic drag is up 90% and there is an extra 1.7 m/s² of resistance on top, so powder is slow — a tucked run through a deep field is a full gear down.
• It throws a wake. The board pushes a bow wave of snow that reads from the chase camera.
• Landings are kinder. Impact is reduced by 45% and every landing window is widened by up to 17°. A rotation that would have been a wipeout on hardpack can be a sketchy landing in deep powder, and a sketchy one can come up clean.

Powder is where you throw the big rotation. It is not where you set a distance record.

Where they are

Both surfaces are laid out by the same deterministic noise as the terrain, so a patch is always in the same place — two riders in a race hit the identical ice at the identical metre. Powder fields are broad and slow-changing; ice patches are smaller and sharper-edged.

Ice grows with depth. The threshold that decides where a patch forms eases as the mountain deepens (see how the mountain is built): over a sample grid, ice covers about 29% of the ground near the top and about 49% six kilometres down. Powder does not scale — it is a feature of the mountain, not a punishment.

Nothing grows through ice, so frozen patches are open ground: the trees and rocks scatter around them, never on them. A big ice field is often the cleanest line through a tight section, if you can hold it.