冰川与冰盖

了解冰川和冰盖的形成与运动方式：积雪经过数百年累积并被压成致密的冰，冰川在自身重力的作用下缓慢向下流动，侵蚀出U形山谷并堆积冰碛物；格陵兰和南极冰盖所含的冰足以使海平面上升超过65米；从这些冰盖中钻取的冰芯含有被封存的气泡，可揭示地球长达80万年的气候历史。

Understand how glaciers and ice sheets form and behave — snow accumulates over centuries and compresses into dense ice, glaciers flow slowly downhill under their own weight carving U-shaped valleys and depositing moraines; the Greenland and Antarctic ice sheets together hold enough ice to raise sea levels by over 65 metres; and ice cores drilled from these sheets contain trapped air bubbles that reveal Earth's climate history going back 800,000 years

学习证据 / Evidence

• 描述冰川的形成过程：积雪不断累积、受压，变成致密的冰，并在自身重力作用下缓慢流动。
• 解释格陵兰和南极冰盖所含的水量如果融化，足以使海平面大幅上升。
• 描述冰芯如何通过封存数十万年前的气泡来揭示气候历史。

• Describe how glaciers form: snow accumulates, compresses, and becomes dense ice that flows slowly under its own weight
• Explain that the Greenland and Antarctic ice sheets hold enough water to raise sea levels dramatically if melted
• Describe how ice cores reveal climate history through trapped air bubbles from hundreds of thousands of years ago

评估问题 / Assessment

{{name}}能否解释冰川是如何由一层层积雪受压变成冰而形成的，它们如何缓慢地侵蚀出山谷，以及科学家为何钻取冰盖来了解数千年前地球的气候？

Can {{name}} explain how glaciers form from layers of snow pressed into ice, how they slowly carve valleys, and that scientists drill into ice sheets to learn about Earth's climate thousands of years ago?