1.12 Concepts of Geomorphic Cycles and Landscape Development

Case Study 1: Concepts of Geomorphic Cycles and Landscape Development – Himalayas and Appalachian Mountains

Models/Theories/Laws:

• Various Schools: Cyclic School, Non-Cyclic School, Non-Catastrophic School
• Davis’ Geomorphic Cycle – Youth, maturity, and old age stages.
• Penck’s Theory of Landscape Evolution – Continuous uplift and erosion.
• Dynamic Equilibrium Model – Balance between tectonic forces and erosion.

Recent Data:

• Himalayas: GNSS data confirms ongoing uplift (~5 mm/year) and erosion-driven landscape evolution.
• Appalachians: Long-term erosion shaping mature landforms.
• Satellite Imagery: Landscape transformation observed in both regions.

Spatial Variation:

• Himalayas: Active tectonic uplift and rapid erosion.
• Appalachians: Mature landscape with subdued relief.

Temporal Variation:

• Himalayas: Continuous uplift since India-Eurasia collision (~50 MYA).
• Appalachians: Erosion-dominated landscape evolution over ~300 MYA.

Insight:

The Himalayas and Appalachians exemplify geomorphic cycles, validating Davis’ and Penck’s models through uplift, erosion, and landscape transformation.