GLACIOLOGY — Identify the smallest glacier type Among the common glacier categories, which type is generally the smallest in areal extent?

Introduction / Context:
Glaciers are classified by geometry and setting. Recognizing relative sizes helps in understanding their dynamics and climate sensitivity.

Given Data / Assumptions:

• Continental glaciers (ice sheets) cover vast areas (e.g., Antarctica, Greenland).
• Piedmont glaciers spread out at mountain fronts after exiting valleys.
• Alpine (mountain/valley) glaciers are confined to valleys and cirques.

Concept / Approach:
Mountain (alpine) glaciers occupy individual valleys or cirques. They are orders of magnitude smaller than continental ice sheets and typically smaller than piedmont glaciers, which can coalesce into broad lobes at foothills.

Step-by-Step Solution:
Compare types by scale: ice sheets > piedmont lobes > valley/alpine glaciers.Identify the minimum scale category → mountain/alpine.Confirm typical examples: small cirque glaciers vs massive ice sheets.

Verification / Alternative check:
Topographic maps and satellite imagery consistently show alpine glaciers as the smallest mapped glacial bodies relative to piedmont and continental forms.

Why Other Options Are Wrong:
Continental — the largest class.Piedmont — can spread widely at mountain bases.Ice shelves — can be extensive floating extensions of ice sheets.

Common Pitfalls:
Assuming “piedmont” means foot-of-mountain and therefore small; actually these lobes can be large sheets.

Final Answer:
mountain or alpine glaciers