Antarctic Ice Sheet

Definition

The Antarctic Ice Sheet is the largest single mass of ice on Earth, covering approximately 14 million square kilometers and containing about 60% of the world's freshwater ice. It plays a crucial role in regulating global sea levels and climate, as its melting contributes significantly to rising ocean levels and alters oceanic circulation patterns. Understanding the dynamics of this ice sheet is vital for grasping broader changes in the cryosphere, including glaciers and sea ice.

5 Must Know Facts For Your Next Test

1. The Antarctic Ice Sheet is divided into two main components: the East Antarctic Ice Sheet and the West Antarctic Ice Sheet, each with different stability and dynamics.
2. Recent studies have shown that parts of the Antarctic Ice Sheet are losing mass at an accelerated rate due to climate change and rising ocean temperatures.
3. The melting of the Antarctic Ice Sheet is expected to contribute to global sea level rise by several meters over the next few centuries if current trends continue.
4. Ice shelves, which are floating extensions of the ice sheet, act as barriers to further ice flow into the ocean, but their collapse can lead to increased ice discharge.
5. The Antarctic Ice Sheet has undergone significant changes during past climate warm periods, providing insights into potential future scenarios for sea level rise.

Review Questions

• How do changes in the Antarctic Ice Sheet affect global sea levels?
  • Changes in the Antarctic Ice Sheet have a direct impact on global sea levels because it contains a vast majority of Earth's freshwater ice. When parts of the ice sheet melt or collapse, they contribute additional water to the oceans, leading to rising sea levels. Understanding these changes helps scientists predict future scenarios for coastal communities and ecosystems that are at risk from flooding.
• What mechanisms contribute to the instability of the West Antarctic Ice Sheet compared to the East Antarctic Ice Sheet?
  • The West Antarctic Ice Sheet is considered more vulnerable due to its grounding lines being below sea level and its reliance on relatively warm ocean currents. As these currents erode the base of ice shelves, they can destabilize the entire ice sheet leading to increased melting and acceleration of ice flow into the ocean. In contrast, the East Antarctic Ice Sheet is generally more stable due to its higher elevation and thicker ice coverage.
• Evaluate the implications of Antarctic Ice Sheet melting for global climate systems and human populations.
  • The melting of the Antarctic Ice Sheet has profound implications for global climate systems and human populations. It not only contributes significantly to rising sea levels but also disrupts ocean circulation patterns that regulate climate. This disruption can lead to extreme weather events globally and threaten coastal communities with flooding. Additionally, these changes can impact marine ecosystems, affecting fish populations and livelihoods dependent on healthy oceans.

Related terms

Glaciers: Large, slow-moving masses of ice formed from compacted snow that flow under their own weight, significantly influencing landscapes and sea levels.

Sea Ice: Frozen seawater that forms on the ocean surface, playing a crucial role in regulating ocean temperatures and ecosystems.

Cryosphere: The frozen water part of the Earth system, which includes ice sheets, glaciers, sea ice, and permafrost, significantly affecting climate and sea levels.