Which mechanism primarily causes cirque expansion in periglacial environments?

💡 Explanation

When water freezes within cracks along the bergschrund, frost wedging expands the cirque headwall because ice volume increases, generating pressure exceeding the rock strength, causing fracturing and removal. Therefore frost wedging results, rather than ablation, sliding, or chemical weathering, which are less effective at headwall erosion.

• Which atmospheric phenomenon is intensified from the Foehn effect, leading to increased wildfire risk?
• Which mechanism increases methane release from thawing permafrost in arctic tundra regions?
• Which mechanism reduces surface salinity in high-latitude oceans when warming temperatures accelerate glacial meltwater outflow?
• Which consequence results when excessive floodplain construction reduces alluvial storage?
• Which mechanism causes the transformation of an oxbow lake into a marsh environment over time?
• Which mechanism alters surface salinity within subtropical gyres located far from landmasses?