WHAT IS CRUSTAL EXTENSION AND WHICH GLOBAL LANDSCAPE FEATURES DOES IT GIVE

RISE TO?

CRUSTAL EXTENSION

CrustAstheno-sphereUpper

Mantle

CRUSTAL EXTENSION

CRUSTAL EXTENSION

CrustalThinning

CRUSTAL EXTENSION

CrustalThinning

CRUSTAL EXTENSION

CrustalThinning

CrustalFaulting

DIVERGENCE. 1

Old Crustal Block

DIVERGENCE. 2

Block 1 Block 2CrustalThinning &Faulting

Large reservoir ofliquid magma closeto surface of crust

DIVERGENCE. 2

Active VolcanoesLong DeepLakes

Block 1 Block 2

DIVERGENCE. 3

Block 1 Block 2

Crustal blocks moving further apart

DIVERGENCE. 3

Block 1 Block 2

Crustal blocks moving further apart

Older volcanic rocks cooled, solidifies, contracts and adheres to blocks.

DIVERGENCE. 3

Block 1 Block 2

Crustal blocks moving further apart

Active volcanicity still connected to reservoir in upper mantle

Older volcanic rocks cooled, solidifies, contracts and adheres to blocks.

DIVERGENCE. 3

Block 1 Block 2

Crustal blocks moving further apart

Older volcanic rocks cooled, solidifies, contracts and adheres to blocks.

Active volcanicity still connected to reservoir in upper mantle.

Sea invades long narrow inlet.

DIVERGENCE. 4

Block 1 Block 2

Crustal blocks moving further apart

DIVERGENCE. 4

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

DIVERGENCE. 4

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Younger volcanic further from block.

DIVERGENCE. 4

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Younger volcanic further from block.

Active volcanicity still connected to reservoir in upper mantle

DIVERGENCE. 4

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Younger volcanic further from block.

Active volcanicity still connected to reservoir in upper mantle

Sea broadening, shallow water, volcanic islands in middle

DIVERGENCE. 5

Block 1 Block 2

Crustal blocks moving further apart

DIVERGENCE. 5

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

DIVERGENCE. 5

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Old volcanic further from block.

DIVERGENCE. 5

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Old volcanic further from block.

Young volcanic near mid-ocean.

DIVERGENCE. 5

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Old volcanic further from block.

Young volcanic near mid-ocean.

Active volcanicity in mid-ocean.

DIVERGENCE. 5

Block 1 Block 2

Crustal blocks moving further apart

Oldest volcanic rocks near edge of block.

Old volcanic further from block.

Young volcanic near mid-ocean.

Active volcanicity in mid-ocean.

Large ocean basin underlain by volcanic rocks symmetrically distributed

Block 1 Block 2

EAST AFRICAN RIFT VALLEY

Goma, Democratic Republic of Congo

Rwanda

EAST AFRICAN RIFT VALLEY

1

23

4

5

5 HIGHEST PEAKSIN AFRICA

EAST AFRICAN RIFT VALLEY

1

23

4

5

2nd and 3rd DEEPESTLAKES IN THEWORLD

THE WORLD'S 10 LARGEST LAKES

Volume of Lake (km3)

0 5000 10000 15000 20000 25000

Dep

th (

m)

0

250

500

750

1000

1250

1500

1750

2000Average DepthMaximum DepthHighest Point in Florida

MaxMeanVolAreaContinentNameDepth (m)depth (m)(km3)(Km2)

1741730.22300031500AsiaBaikal1435574.51890032900AfricaTanganyika406193.51600082680North AmericaSuperior706250.0772530900AfricaMalawi28180.6468058100North AmericaMichigan29959.9358059800North AmericaHuron9239.1270069000AfricaVictoria

23690.0171019000North AmericaOntario15639.3107027200North AmericaGreat Slave13733.4101030200North AmericaGreat Bear

Bai

lkal

Tan

gany

ika

Sup

erio

rMal

aw

i

Hur

on

Mic

higa

n

Vic

toria

Ont

ario

Gre

at B

ear

and

Gre

at S

lave

GLOBAL DISTRIBUTION OF EARTHQUAKES

03.02.b1

GLOBAL DISTRIBUTION OFVOLCANOES

Block 1 Block 2

Saudi Arabia, Egypt, Sudan and Eritrea, fit together like pieces of a jig-saw puzzle across either side of the Red Sea.

03.00.a1f

10.08.a4

Block 1 Block 2

Volcanic lavas have filled the rift on the African side (Afar Triangle), creating strategic choke-point between Somalia and Yemen!

USS Cole17 Died39 InjuredAden, 2000 Former Yemeni

President, Ali Abdullah Saleh

Extinct volcano!

Block 1 Block 2

Suez Canal links Mediterranean and Indian Ocean via the Red Sea.

Grandfather, Fred Mundy D.C.M.

Suez – Jerusalem 1917-18

Aden: British controlled 1839-

1967.

GLOBAL DISTRIBUTION OF EARTHQUAKES

03.02.b1

GLOBAL DISTRIBUTION OFVOLCANOES

Pre-1967 Arab-Israeli War border of Israel

THE WEST BANKSETTLEMENTS

Jerusalem

GOLAN HEIGHTS (EAST BANK!)

ATLANTIC OCEAN

ATLANTIC OCEANICELAND

ATLANTIC OCEAN

RonaldReagan

MargaretThatcher

10.10.b1

BRITAIN EUROPENORTH SEA

ARGENTINA

FALKLANDSMALVINAS

SOUTHATLANTIC

OIL AND NATURAL GAS

ATLANTIC OCEAN

ST. HELENA

ELBA

GLOBAL DISTRIBUTION OF EARTHQUAKES

03.02.b1

GLOBAL DISTRIBUTION OFVOLCANOES

NB. THESEMUST APPEAR ABOVE SEA LEVEL TO BE PLOTTED!

10.04.a3

ATLANTIC OCEAN

10.04.a3

INDIAN OCEAN

10.04.a3

PACIFIC OCEAN

10.04.a3

SOUTHERN OCEAN

10.04.a4

THINK! TIME AND SPACE.

I II III IV V

FIVE ACT PLAY

Length of Play = 2 hr

7 version of the play running over a period of 4 hrs

SEVEN THEATERS START THE PLAY AT RANDOM TIMES.

SEVEN SPECTACTORS ARRIVE AT EACH ONE OF THE DIFFERENT THEATERS SIMULTANEOUSLY AND RECORD WHICH ACT THE

PLAY IS IN.

One in Act 1, 1 Act 2, 2 Act3, 2 Act 4, 1 Act 5 -: Roughly proportional to the lengthsof time spent in each act.

We can’t watch the whole play (ocean basin formation), but we can visit many oceanbasins now and assume that they represent the lengths of time that the play would spendin each act if we were able to observe it over time.