Introduction to glaciated upland landscapes

Today, I'm glacier hunting here in the Lake District in England. Although it's hard to imagine, we once had glaciers here in the UK.

Going back eighteen thousand years to the last Ice Age, these mountains were buried in ice and were perfect glacier forming territory and it was these glaciers that radically transformed the landscape into what we see today.

It was high up in the mountains, where the glacier was born in a corrie, or coom as they're known in Wales.

These corries were formed when snow collected year on year in hollows on the mountainside gradually forming incredibly strong tightly packed ice. Once there was enough ice, it started to move because the ice at the bottom, or sole of the glacier, melts under intense pressure from the weight of the ice above, allowing the ice to move in what is known as rotational slip. It's a bit like your bottom sliding down the back of a car seat.

Freeze thaw weathering takes place above the glacier as ice thaws and then refreezes inside cracks or fissures in the rock. Each time water freezes, it expands, widening the crack a small amount. Eventually, the rock will burst apart.

Stone fragments called scree fall onto the glacier. These rocks other debris picked up by the ice at the sole of the glacier. As the glacier moves, abrasion kicks in as these stones scrape along the rock floor and you can see how these stones scower the surface of the land like supercharged sandpaper, deepening and smoothing it.

Over time by melting and refreezing around a large rock, the ice simply lifts it away in a form of erosion known as plucking to create the steep back walls and the armchair shaped hollow of the corrie.

Once the glacier moved beyond the corrie, it carved its way through the valley. V-shaped valleys were turned into U-shaped valleys or glacial troughs by abrasion and plucking.

Smaller and weaker glaciers with less eroding power left behind these hanging valleys in the trough.

When the glacier crashed through the ancient interlocking spurs, it sliced off their ends, leaving behind truncated spurs. And when the ice melted around eleven thousand five hundred years ago, it revealed a landscape transformed by the glaciers. The corries filled with melt water to create tarns and all these rocks and boulders, known as erratic stones were carried down the mountain by you know what. Even more evidence of the incredible power of glaciers here in the Lake District. We did have glaciers in the UK, you just have to look for clues and use your imagination.