Glaciation Flashcards
memorise (22 cards)
🏔️ Corrie – Glacial landform
Armchair-shaped hollow with a steep back wall and tarn (lake).
Formed by nivational processes, freeze-thaw, and rotational ice movement.
Plucking steepens back wall; abrasion deepens hollow.
Found in upland glaciated regions
⛰️ Arete – Glacial landform
Narrow knife-edged ridge.
Formed when two corries erode back-to-back.
Plucking and freeze-thaw weathering sharpen the ridge.
🗻 Pyramidal peak – Glacial landform
Sharp mountain summit.
Formed when three or more corries erode back toward a single peak.
Freeze-thaw and plucking shape the steep sides.
🏞️ U-shaped valley – Glacial landform
Steep sides, flat bottom valley carved by valley glacier.
Glacier erodes via abrasion and plucking, overdeepening the valley floor.
Replaces former V-shaped river valley.
🌉 Hanging valley – Glacial landform
Smaller valley left ‘hanging’ above main U-shaped valley.
Formed when tributary glaciers erode less than the main glacier.
Often forms waterfalls.
💧 Ribbon lake – Glacial landform
long, narrow lake in U-shaped valley.
Forms in areas of differential erosion or dammed by moraines.
Overdeepened by abrasion beneath glacier.
🪨 Roche moutonnée – Glacial landform
Asymmetrical rock mound.
Ice abrades stoss (up-glacier) side; plucks lee (down-glacier) side.
Indicates direction of ice flow.
🌾 Terminal moraine – Glacial landfor
Ridge of unsorted material at glacier’s furthest advance.
Dumped at snout as glacier melts.
Shows maximum extent of glacier.
🐍 Esker – Fluvioglacial landform
Long, winding ridge of sorted sand and gravel.
Deposited by meltwater streams beneath glacier.
Forms as glacier retreats.
⛰️ Kame – Fluvioglacial landform
Mound of sorted sediment.
Deposited by meltwater in ice crevasses or holes (kame terraces too).
Formed during stagnation of melting ice.
🕳️ Kettle hole – Fluvioglacial landform
Depression formed when a block of dead ice melts in outwash plain.
Filled with water to form a kettle lake.
Common in post-glacial landscapes.
🧊 Pingo – Periglacial landform
Ice-core mound found in permafrost areas.
Open-system pingos: groundwater freezes and expands.
Closed-system pingos: trapped water in permafrost zone pushes up frozen dome.
❄️ Ice wedges – Periglacial landform
Formed by repeated freeze-thaw.
Water enters cracks, freezes and expands, widening cracks into wedge shapes.
Key indicator of permafrost processes.
🔘 Patterned ground – Periglacial landform
Surface pattern (circles, stripes) due to frost heave and sorting.
Stones move upward in soil and arrange into patterns over time.
🪨 Plucking – Erosional process
Ice freezes onto bedrock and pulls away fragments as glacier moves.
Leaves jagged terrain, common on lee sides of rocks.
🧽 Abrasion – Erosional process
Rock debris embedded in ice scrapes against bedrock.
Polishes and grooves surface (striations).
Needs basal sliding to occur.
🌡️ Freeze-thaw – Weathering process
Water enters cracks, freezes, expands by 9%, and widens cracks.
Repeated cycles break off rock fragments (scree formation).
Common in periglacial environments.
🌨️ Nivation – Weathering & erosion combo
Snow patch melts and causes weathering, mass movement, and erosion beneath it.
Precursor to corrie formation.
Mix of freeze-thaw and meltwater activity.
🛷 Basal sliding – Glacier movement
Meltwater at base reduces friction, allowing ice to slide.
Dominant in warm-based glaciers.
🌀 Internal deformation – Glacier movement
Ice deforms and flows under its own weight.
Ice crystals rearrange, allowing slow creep.
Key in cold-based glaciers where basal melting is minimal.
⛏️ Mass movement – Post-glacial modification
Includes rockfalls, landslides on valley sides.
Triggered by meltwater, freeze-thaw, or ice retreat destabilising slopes.
🇳🇴 Svalbard – Arctic glacial landscape & climate change hotspot
Glacier coverage: Approximately 60% of Svalbard is glacierized, encompassing over 2,100 glaciers
Significance: Svalbard serves as a critical indicator for studying the impacts of climate change on glacial environments.
