Glaciers and ice ages

In short: Glaciers are large ice masses that form over years from compressed snow and move slowly. Ice ages are periods of Earth’s history when large parts of the planet were permanently covered in ice.

In more detail: Earth has gone through several major ice ages, separated by warmer interglacial periods, one of which we currently live in.

In detail

• Glacier formation: Over decades, snow compresses into ice that flows downhill under its own weight.
• Glacier types: Valley glaciers flow through mountain valleys, while ice sheets like those in Antarctica cover entire continents.
• Erosive power: Glaciers shape landscapes by grinding and transporting rock over long periods.
• Ice age cycles: Fluctuations in Earth’s orbital parameters affect sunlight exposure and trigger periodic ice ages.
• Last ice age: About 20,000 years ago, ice sheets covered large parts of Northern Europe and North America.
• Glacier melt today: Current climate change significantly accelerates glacier melt worldwide.
• Consequences of retreat: Melting glaciers contribute to sea level rise and change local water supplies (polarregionen-arktis-und-antarktis, klimazonen-der-erde).