Glacial Systems and Landscapes | 冰川系统与地貌

📚 Glacial Systems and Landscapes | 冰川系统与地貌

Glacial systems and landscapes are a core topic in Edexcel A-Level Geography. They examine how glaciers operate as systems, how ice shapes the land through erosion and deposition, and how these environments respond to change over time.

冰川系统与地貌是爱德思 A-Level 地理的核心主题。它研究冰川如何作为系统运行、冰如何通过侵蚀和沉积塑造地表，以及这些环境如何随时间响应变化。

1. The Glacial System: Inputs, Stores and Outputs | 冰川系统：输入、储存与输出

A glacier is an open system because it exchanges both energy and matter with its surroundings. The main inputs are snowfall, avalanches and wind-blown snow; stores include glacier ice, meltwater and rock debris; outputs are meltwater, evaporation, sublimation and iceberg calving.

冰川是一个开放系统，因为它与周围环境交换能量和物质。主要输入包括降雪、雪崩和风吹雪；储存包括冰川冰、融水和岩屑；输出包括融水、蒸发、升华和冰山崩解。

Energy enters the system mainly from solar radiation and geothermal heat, while gravity drives the downslope transfer of ice and sediment. A healthy glacier depends on a positive balance between inputs and outputs over a long period.

能量主要通过太阳辐射和地热进入系统，重力驱动冰和沉积物向下坡转移。健康的冰川依赖长期内输入大于输出，即正平衡。

2. Glacier Mass Balance and Equilibrium Line | 冰川质量平衡与平衡线

Mass balance is the difference between accumulation (the input of snow and ice) and ablation (melting, sublimation and calving) over a hydrological year. If accumulation exceeds ablation, the glacier advances; if ablation exceeds accumulation, the glacier retreats.

物质平衡是积累（雪和冰的输入）与消融（融化、升华和崩解）在一个水文年内的差值。如果积累大于消融，冰川前进；如果消融大于积累，冰川后退。

Net balance = Accumulation − Ablation

净平衡 = 积累量 − 消融量。净平衡为正值时冰川前进，为负值时冰川后退。

The equilibrium line altitude (ELA) separates the accumulation zone in the upper part of the glacier from the ablation zone in the lower part. The ELA rises when the climate warms or becomes drier, and it falls when the climate cools or becomes wetter.

平衡线高度（ELA）将冰川上部的积累带与下部的消融带分开。当气候变暖或变干时，平衡线上升；当气候变冷或变湿时，平衡线下降。

3. Glacier Movement: Mechanisms and Rates | 冰川运动：机制与速率

Glaciers move by two main mechanisms: internal deformation and basal sliding. Internal deformation, also called creep, occurs when ice crystals deform and slide over each other under pressure, allowing the whole mass to flow slowly.

冰川通过两种主要机制运动：内部变形和基底滑动。内部变形又称蠕变，是冰晶在压力下相互变形和滑动，使整个冰体缓慢流动。

Warm-based glaciers have meltwater at their base, which reduces friction and permits faster basal sliding. Cold-based glaciers are frozen to bedrock and move mainly by internal deformation, so they erode less and are often less mobile.

温基冰川底部有融水，能减少摩擦并允许较快的基底滑动。冷基冰川冻结在基岩上，主要通过内部变形运动，因此侵蚀较少，移动性通常也较低。

Rates of movement vary from a few metres per year in polar glaciers to several hundred metres per year in temperate glaciers, and can change seasonally with meltwater inputs.

冰川运动速率从极地冰川的每年数

Published by TutorHao | A-Level Mathematics Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）