Consider the following statements regarding high-altitude periglacial landforms found in high mountain ranges globally, including the Greater Himalayas: Statement I: Solifluction sheets and rock glaciers develop extensively in areas subject to intense freeze-thaw cycles above the tree line. Statement II: Permafrost underlying these high-altitude zones remains permanently frozen throughout the year regardless of summer surface air temperatures. Which of the following is correct?

💡 Solution & Explanation

Both statements are correct; high mountain ranges feature periglacial processes where freeze-thaw weathering drives solifluction and rock glacier movement, while underlying permafrost remains continuously below zero degrees Celsius at depth. These fragile periglacial environments are sensitive to global climate change, which can trigger slope destabilization and glacial lake outburst floods. Similar periglacial landforms occur in upper elevations of North Sikkim near snow-covered crests and peaks.