Pangaea Ultimathe Future

Scientists are interested in what the future may be like and how the Earth may eventually look. What will its climate be like? How will its ecosystems function? How many of the changes will be natural, and how many will be human caused? In the case of plate tectonics, geologists have been able to trace the movement of the Earth's plates backward in time in order to determine the geographic positions of the continents and the resulting climates that affected them, such as tropical, polar, or temperate.

The Earth's plate tectonic process continues today, and scientists wonder what the geographic configuration of the continents will one day become. Although these projections are theoretical, they present an intriguing view of what may lie in the future and what role climate may play.

Dr. Christopher R. Scotese, a geologist at the University of Texas, believes that projecting the locations of continents 50 million years from now is not difficult. Projecting beyond that, however, is much more problematic because unpredictable cause-and-effect incidents can drastically change results. "Fifty million years is fairly straightforward. It's like you're driving on the highway and you want to know where you're going to be in 10 minutes. You check the speedometer, do a calculation, and project your present motion. But beyond 50 million years—like on the highway, unexpected things can happen."

Projecting further into the future is more difficult because it involves far more than simple extrapolations. Instead, rules must be developed that govern not only their movements but also where subduction zones and deep ocean trenches will form. They may change shape but seldom disappear altogether because bedrock weighs little compared to the dense ocean crust. Continents literally float, as do mountains. Once formed, they tend to persist and disappear only after ages of erosion wear them down. The difficult part is to predict the development of new subduction zones in the seafloor and to calculate how rapidly such zones will rearrange the continents. "It's hard

(opposite page) Dr. Christopher R. Scotese's Paleomap Project. (A) This is what the Earth's distribution of continents may look like in 50 million years from now. The Atlantic may widen, Africa will collide with Europe closing the Mediterranean, Australia will collide with Southeast Asia, and California will slide northward up the coast to Alaska. (B) This is Pangaea Ultima 250 million years from now. It will form as a result of the subduction of the ocean floor of the North and South Atlantic beneath eastern North America and South America. This supercontinent will have a small ocean basin trapped at its center. (Source: www.scotese.com)

to understand all the forces down there," Scotese says. "There's probably some input from the mantle. It probably has some say on which way the plates go."

O Future world +50 Ma

East Pacific Rise

O Future world +250 Ma

PACIFIC OCEAN

3 Ancient landmass \ Modern landmass

Subduction zone (triangles point in the direction of subduction) — Seafloor spreading ridge

Baja California

PACIFIC

O Future world +50 Ma

Ecological Footprint

Baja California

PACIFIC

OCEAN

East Pacific Rise

O Future world +250 Ma

OCEAN

PACIFIC OCEAN

Pangea Ultima

3 Ancient landmass \ Modern landmass

Subduction zone (triangles point in the direction of subduction) — Seafloor spreading ridge

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Several geologists have predicted that in 50 million years, the tectonic movement of the San Andreas fault will have moved Los Angeles northward to the area of San Francisco. Eventually, Los Angeles will move north as far as Anchorage, Alaska.

In 1998, Dr. Scotese created a project called the Paleomap Project (www.scotese.com), which projects what the continents may look like 50 million years from now and 250 million years from now. He calls the configuration predicted for 250 million years from now Pangaea Ultima. In order to figure out the eventual location of continents, Dr. Scotese used a computer algorithm to simulate the mechanisms that move the plates, such as where subduction zones recycle and melt the plates, where trenches in the ocean floor tear continents apart, where ridges in the ocean floor tear the ocean floor apart and move continents away from one another, and where other continents are being pushed together, creating new mountain ranges.

Dr. Scotese believes the most difficult part of modeling the future distribution of the continents is predicting the development of new subduction zones and determining how aggressive they will be in moving the plates compared to older subduction zones. In addition to the forces on the crust, forces deep inside the Earth's mantle play a part in plate tectonics and are difficult to model.

Dr. Scotese predicts that the processes that will lead to the Earth 250 million years from now, Pangaea Ultima, will begin with the closing of the Mediterranean. Then, 25 to 75 million years from now, Australia will migrate north, collide with Indonesia and Malaysia, then turn counterclockwise and collide with the Philippines and Asia, eventually merging them all together. In addition, Antarctica will migrate northward, upon which its icecap will melt. About 100 million years from now, it will enter the Indian Ocean. Then, 50 million years later, it will settle between Madagascar and Indonesia, making the Indian Ocean an inland sea.

The most drastic change by far will be the closing of the Atlantic Ocean. Then, 200 million years from now, Newfoundland will collide with Africa, and Brazil will butt up against South Africa. Finally, 250 million years from now, all the continents will have merged into a new super continent, Pangaea Ultima, that will encircle the remnants of the old Indian Ocean.

This is just one prediction of what the Earth may look like in the future. Other scientists have projected that instead of the Atlantic Ocean disappearing, the Pacific Ocean may disappear instead, pushing both North and South America into Asia and forming a hypothetical new continent called Amasia.

These are nevertheless hypothetical projections of the Earth's future created by computer models. While no one knows for sure what the Earth will look like in the distant future, it does bring up interesting questions about what the Earth's climate may be like. If the bulk of the continents are located near the equator, what will have happened to those ecosystems that were not tropical? Likewise, what about tropical habitats that now may reside in the mid-latitudes? In addition, if Antarctica migrates north and its ice cap completely melts, what will sea levels be? What will be the composition of seawater, and what will be the new configuration of the major ocean currents?

With a new spatial arrangement of the continents, there will undoubtedly be a new distribution of ocean currents, which in turn will affect global heat distribution. This will affect vegetation distributions, which, in turn, will affect the carbon cycle. Finally, in light of all these hypothetical changes and their effects on energy, heat, and the carbon cycle, what role will global warming have had on all this? Will global warming have been controlled 250 million years earlier so that there are still productive civilizations left to see what the actual Pangaea Ultima will look like? These are the questions climate scientists are working diligently to answer today.

the geological timescale

ERA

period

EPocH

(millions of years)

first life-forms

geology

Quaternary

Holocene

0.01

Humans

Ice age

Pleistocene

3

Neogene

Pliocene

11

Mastodons

cascades

cenozoic

Miocene

26

saber-toothed tigers

Alps

Tertiary

oligocene

37

Paleogene

Eocene

54

Whales

Paleocene

65

Horses, Alligators

Rockies

cretaceous

135

Birds

Mesozoic

Jurassic

210

Mammals

sierra Nevada Atlantic

Triassic

250

Dinosaurs

Permian

280

Reptiles

Appalachians

Pennsylvanian

310

Trees

ice age

carboniferous

Mississippian

345

Amphibians Insects

Pangaea

Paleozoic

Devonian

400

sharks

silurian

435

Land plants

Laursia

ordovician

500

Fish

cambrian

544

sea plants shelled animals

Gondwana

Proterozoic

700

Invertebrates

2500

Metazoans

3500

Earliest life

Archean

4000

oldest rocks

4600

Meteorites

IA

Periodic Table of the Elements i-Atomic number

18 VINA

1.00794

IIA

6.941 —

- Symbol

13 14 15 16 17 IIIA IVA VA VIA VIIA

2 He

4.0026

6.941

9.0122

-Atomic weight

11 12 IB IIB

10.81

6c 12.011

14.0067

15.9994

18.9984

20.1798

22.9898

24.3051

3 4 5 6 7 HIB IVB VB VIB VIIB

8 9 10 VIIIB VIIIB VIIIB

26.9815

28.0855

30.9738

32.067

39.948

40.078

44.9559

47.867

50.9415

51.9962

54.938

55.845

58.9332

58.6934

63.546

65.409

69.723

72.61

74,9216

78.96

79.904

85.4678

87.62

88.906

92.9064

95.94

(98)

106.42

112.412

114.818

121.760

127.60

126.9045

131.29

132.9054

137.328

70ir

174.967

178.49

180.948

183.84

186.207

190.23

192.217

195.08

196.9655

200.59

207.2

208.9804

(209)

(210)

(222)

(226)

102 *

(260)

(261)

(262)

(2öü

(263)

(271)

(277)

(284)

(285)

Uus Uuo

? ?

-^Lanth Actin

Numbers in parentheses are atomic mass numbers of most stable isotopes.

anoids oids

138.9055

140.115

144.24

150.36

151.966

157.25

158.9253

66 162.^00

164.9303

167.26

168.9342

173.04

(227)

232.038

231.036

238.028«

(237)

(244)

243

(247)

(247)

(251)

(259)

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(g) none

(c) nonmetallics

element symbol

a.n.

carbon C

6

hydrogen H

1

(g) chalcogen

(c) nonmetallics

element symbol

a.n.

oxygen o

8

polonium Po

84

selenium Se

34

sulfur s

16

tellurium Te

57

ununhexlum Uuh

116

(g) alkali metal

(c) metallics

element symbol

a.n.

cesium cs

55

francium pr

87

lithium y

3

potassium <

19

rubidium Rb

37

sodium Na

11

(g) alkaline earth metal

(c) metallics

element symbol

a.n.

barium Ba

56

beryllium Be

4

calcium Ca

20

magnesium Mg

12

radium Ra

88

strontium Sr

38

© Infobase Publishing

The Chemical Elements

(g) none (c) metallics

element

symbol

a.n.

element

symbol

a.n.

aluminum

Al

13

scandium

Sc

21

bohrium

Bh

107

seaborglum

Sg

106

cadmium

Cd

48

silver

Ag...

47

chromium

Cr

24

tantalum

Ta

73

cobalt

Co

27

technetium

Tc

43

copper

Cu-.

29

thallium

Tl

81

darmstadtium Ds

110

titanium

Ti

22

dubnlum

Db

105

tin

Sn

50

gallium

Ga

31

tungsten

W

74

gold

Au...

79

ununbium

Uub

112

hafnium

Hf

72

ununtrlum

Uut

113

hassium

Hs

108

ununquadium

Uuq

114

Indium

In

49

vanadium

V

23

iridium

lr ****

77

yttrium

Y

39

iron

Fe

26

zinc

Zn

30

lawrencium

Lr

103

zirconium

Zr

40

lead lutetium manganese meitnerium mercury molybdenum nickel niobium osmium palladium platinum rhenium radium roentgenlurm ruthenium rutherfordlum

111 44 104

(g) pnictogen (c) metallics element_symbol a.n.

arsenic antimony bismuth nitrogen phosophorus

ununpentium Uup

33 51 83 7 15 115

(g) none (c) semimetallics element symbol a.n. boron B 5

germanium Ge 32 silicon Si 14

(g) pnictogen (c) metallics element_symbol a.n.

(g) actinoid (c) metallics

element

symbol

a.n.

actinium

Ac

89

americium

Am

95

berkelium

Bk

97

californium

Cf

98

curium

Cm

96

einsteinium

Es

99

fermlum

Fm

100

mendelevium

Md

101

neptunium

Np

93

nobelium

No

102

Plutonium

Pu

94

protactinium

Pa

91

thorium

Th

90

uranium

U

92

(g) halogens (c) nonmetallics

element

symbol

a.n.

astatine

At*

85

bromine

Br

35

chlorine

CI

17

fluorine

F

9

iodine

I

53

ununseptium

Uus*

117

a.n. = atomic number (g) = group (c) = classification

(g) lanthanoid (c) metallics

element

symbol

a.n.

cerium

Ce

58

dysprosium

Dy

66

erbium

Er

68

europium

Eu

63

gadolinium

Gd

64

holmium

Ho

67

lanthanum

La

57

neodymium

Nd

60

praseodymium Pr

59

Promethium

Pm

61

samarium

Sm

62

terbium

Tb

65

thulium

Tm

69

ytterbium

Yb

70

(g) noble gases (c) nonmetallics

element

symbol

a.n.

argon

Ar

18

helium

He

2

krypton

Kr

36

neon

Ne

10

radon

Rn

86

xenon

Xe

54

ununoctium

Uuo

118

* = semimetallics (c) ** = nonmetallics (c) *** = coinage metal (g) **** = precious metal (g)

+2 -1

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    How can pangaea ultima affect people?
    12 months ago

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