In IAM News’s Winter Special, Iphigenia explored the potential for InSAR to monitor the behaviour of glaciers, and how this analysis may be used for assessing the development of wider climate change. Today, let’s take a closer look at the concept of the plastic flow of ice, and what factors may affect this process.

What is the Plastic Flow of Ice?

The plastic flow of ice refers to the ability of glacial ice to deform and flow over time, much like a slow, viscous fluid. Unlike brittle fracture, which results in the formation of crevasses, plastic flow involves the gradual movement of ice masses under the influence of gravity. This movement is not only central to the dynamics of glaciers themselves but plays a pivotal role in shaping our planet’s landscape.

Temperature

One of the primary factors influencing the plastic flow of ice is the temperature gradient within the glacier itself. Naturally, ice deforms more rapidly when subjected to higher temperatures, causing it to behave like a pliable material rather than a rigid solid. Warmer conditions at the glacier bed enhance basal sliding, facilitating the movement of ice over the underlying terrain.

Pressure and Stress

The weight of overlying ice exerts pressure on the layers beneath, inducing stress within the glacier’s structure. This stress can lead to the deformation of ice crystals, allowing them to slide past each other and contribute to the plastic flow. Understanding the distribution of stress within a glacier is a useful indicator for analysts in predicting movement patterns.

Subglacial Water

Another contributing factor to the sliding phenomenon is the interaction between the glacier and the underlying water. The presence of liquid water at the glacier bed acts as a lubricant, reducing friction, and facilitating faster ice movement. Understanding the dynamics of subglacial hydrology is essential for comprehending the intricacies of glacial motion.

Geothermal Heat Flux

The heat emanating from the Earth’s interior, known as geothermal heat flux, contributes to the thermal regime of glaciers. This heat influx influences the temperature distribution within the glacier and affects the rate of plastic flow. Regions with higher geothermal heat flux may experience increased ice deformation.

In conclusion, the plastic flow of ice is a dynamic and intricate process shaped by a multitude of factors. By unravelling the mysteries of plastic flow through analysis using remote sensing techniques such as InSAR, we can gain valuable insights into the response of glaciers to environmental changes, informing our understanding of climate dynamics.

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