CASE STUDY - UPLAND GLACIATED VALLEY IN UK

Question 1

What’s the valley called

Where is it

Answer 1

Ogwen + Nant Ffrancon Valley

North Wales

Question 2

When was the last glacial maximum where wales was affected by an ice cap

Answer 2

20,000BP (devensian age)

Question 3

When was the mini ice age

Answer 3

1200 - Loch Lomond Advance

Question 4

When did warmer periods begin - ice reduces + fluvioglacial and periglacial processes occur

Answer 4

10,000 years BP

Holocene Starks

Question 5

What was the period that caused the glacial landforms in the British isles today
When was it

Answer 5

Quaternary period (2.4 million BP)

Question 6

What is Ogwen + Nant Ffrancon valley produced by

Answer 6

A north westerly moving glacier flowing away from the central part of snowdonia

Question 7

What is there at the Ogwen + Nant Ffrancon valleys head + lower end

Answer 7

Head - rock step marked by a waterfall

Lower end - terminal Moraine

Question 8

11 landforms to know in Ogwen + Nant Ffrancon valley

Answer 8

Glacial trough
Arête
Truncated spur
Ribbon lake
Corrie/cwm/cirque
Hanging valley
Rock step
Misfit stream
Infilled glacial lake
Corrie lake

Question 9

What did the glacier do to Nant Ffrancon valley

Answer 9

Widened, straightened + deepened it
Truncating interlocking spurs
Leaving a u shaped glacial trough

Question 10

What formed the Nant Ffrancon valleys flat valley floor today

Answer 10

The ribbon lake on the valley floor filling with sediments over time

Question 11

What’s the Nant Ffrancon valley arête called

Answer 11

Y Gribin

Question 12

What mountains were 2 corries eroded back into forming the Y Gribin arête

Answer 12

Glyder mountains

Question 13

Where’s the Nant Ffrancon valley truncated spurs

Answer 13

At the bottom of Y Gribin by Cwm Idwal

Question 14

What’s the Nant Ffrancon valley ribbon lake called

Answer 14

Llyn Ogwen

Question 15

3 ways over-deepening of the glacial trough has occurred to form Llyn Ogwen ribbon lake

Answer 15

Softer rock being eroded easier + harder rock resisting erosion
Thicker glacial ice
Compression flow - more erosion

Question 16

What’s the Nant Ffrancon valley corrie called

Answer 16

Cwm Idwal

Question 17

Describe the shape of Cwm Idwal

Answer 17

Doesn’t fit usual circular pattern

It’s linear (1.5km long + only 1km wife from arête -> arête)

Question 18

Describe the altitude of Cwm Idwal

Why’s it like this

Answer 18

A lot deeper + lower than other corries

As : it lies below lowest point in Glyderau range, it had greater volumes of ice so was more erosion + it lies along a line of geological weakness

Question 19

What’s the Nant Ffrancon valley corrie lake in Cwm Idwal called

Answer 19

Llyn Idwal

Question 20

Describe Llyn Idwal corrie lake

Answer 20

Unusual linear shape
Surprisingly shallow (10m) max, average depth is 3m

Question 21

What’s a hanging valley Nant Ffrancon valley called

Answer 21

Cwm Cygwin

Question 22

What slopes of Nant Ffrancon valley have a number of hanging valleys

Answer 22

NE slopes (eroded more deeply here)

Question 23

What’s the Nant Ffrancon valley rock step + waterfall called

Answer 23

Rhaeadr Ogwen

Question 24

What’s the height drop at the Nant Ffrancon rock step that’s marked by the Rhaeadr Ogwen waterfall

Answer 24

100m

Question 25

What’s the Nant Ffrancon valley misfit stream that meanders on the valley floor called

Answer 25

Afon Ogwen

Question 26

What period are we in now

Answer 26

Quaternary period (last 2.58 million years)

Question 27

What has there been throughout the quaternary period

What’s the name of the cycle

Answer 27

Many glacial + interglacial fluctuations on a 41,000 year cycle
Milankovich cycle, more recently a 100,000 year cycle

Question 28

How many glacial have there been in the last 740,000 years

Answer 28

8