Which mechanism primarily deepens fjords during glacial periods?

💡 Explanation

During glacial periods, abrasion by sediment-rich glacial ice deepens fjords because the moving ice acts as a rasp, grinding the bedrock. Therefore, abrasion is the primary deepening mechanism, rather than chemical weathering, tectonic subsidence or thermal expansion alone which play secondary roles or act over longer timescales.

• Which mechanism accelerates surface deformation when permafrost thawing induces solifluction on an Arctic slope with ice wedges?
• Which mechanism causes orographic precipitation on a mountain range near a transform fault?
• Which formation process dominates when wave-cut platforms erode isolated headlands?
• Which mechanism limits lake formation when downcutting rate exceeds sediment deposition in a fluvial valley?
• Which outcome arises when strong katabatic winds erode topographic obstructions in glacial valleys?
• Which mechanism primarily deflects geostrophic currents into coastal boundary currents along continental margins?