Fitness Landscapes of the earth (II) LO27363

From: Leo Minnigh (
Date: 10/09/01

Dear LO'ers,

This is part II of a long walk to great heights and deep depths.

Although the idea of continental drift is already some 100 years old, it
was only in the early 60's that this theory could be sustained by enough
observations from all sorts of disciplines. A whealth of data was produced
after 1956, the International Geophysical Year. This is a year to
remember. Scientists from all over the world and of many different
disciplines cooperated, collaborated, searching together in international
teams, dialoguing and finally publishing (remember it was cold war at that
time; Americans and Russians were working together!). I could not resist
the idea that this was possibly an exemple of a supra-learning
organization, without hierarchy, but of course with a lot of coordination.

Particularly, our knowledge of oceans increased unbelievable in that year
and this enabled a whole series of scientific 'steigerungs'. I mention a

1) the ocean floors are not flat bottoms but nearly all of them have also
under water mountain chains. These chains - referred to as ocean ridges -
have some peculiar characteristics. They are relatively high, generally
3000 - 4000 metres above the average ocean floor. Centrally and lengthwise
of these ridges is a deep canyon with permanent submarine volcanic and
seismic activity. These ridges of different oceans are connected with each
other and form an enormous web around the globe.

2) rocks of the ocean floors are basalts, once molton magma, crystallised
into rocks. During crystallisation the iron rich minerals tend to
orientate themselves to the earth magnatic field. And the strange
discovery made in 1956 was that these minerals are sometimes oriented to
the north, and sometimes to the south. This suggests that the earth
magnetic field reverses its orientation. And these magnetic reversals have
happened some 30 times in the last 120 my at irregular intervals. And the
most remarkable outcome of this discovery was that the pattern of magnetic
reversals in the rocks of the ocean floor is symmetrical on both sides of
the oceanic ridges. This discovery and the discovery that rocks near the
ridge are younger than those far away from the ridges, forms the next

3) oceans are created at the ridges. Magma with basaltic composition
extrudes permanently in the central submarine canyon and the magma
crystallises on both sides of this fissure. Oceans become wider and wider
with a speed of 12 - 20 cm/year. This is rather fast in geological terms.
In a human life time the Atlantic Ocean becomes a metre wider.

If oceans become bigger and bigger without compensation elswhere, the
earth will become also bigger and bigger. This is not the case, the
distance to our neighbours will stay the same, if we like it or not :-).
But if the earth remains her size, than the extra surface created in the
oceans must disappear too. And this happens indeed near the deep oceanic
trenches which occur for instance around the Pacific Ocean, south of
Indonesia and at some other places. At these places the ocean floor
'sinks' into great depths. The 5 km thick oceanic crust together with some
100 km thick upper mantle (together called the ' lithosphere') dips as a
slice under an angle of 40 - 60 degrees underneath the neighbouring
continent. This process of subduction is accompanied by heavy earthquakes
and volcanism. By tracing the locations where earth quakes are triggered,
the subducting plate could be detected to a depth of 800 km. So a kind of
conveyer belt is operating: new oceanic crust is created at the oceanic
ridges, whereas near the trenches the older oceanic crust disappears to
great depths. In this way the surface and mass balance of the earth is

It is still uncertain what the precise 'motor' and mechanism behind this
movement is. It is not possible that the ocean floor is pulled down in the
subduction zone, then the floor will break, nor is the ocean floor pushed
away at the ridge, because the fluid basalt magma has no 'pushing'

Ocean floor is permanently rejuvinated, whereas the continents become
older and older.

This new mechanism is known as 'global tectonics', 'plate tectonics', or
'continental drift'. Thos latter name is somewhat a misnomer because it
reflects more to the model of the old days: drifting continents, like the
woodblock model. In that way one could expect after enough patience that
at a certain moment the ocean floor which was once at one side of the
continent, will appear finally on the other side again. This is not true.
Ocean floors are permanently rejuvinated.

On the whole surface of the globe a number of plates could be
distinguished. The African plate for instance consists of the African
continent together with the eastern half of the south Atlantic ocean floor
and with the western part of the Indian Ocean. The American plate consists
of both American continents and the western half of the Atlantic Ocean.
The western boundary of the American plate is close to the Pacific coast,
so hardly no Pacific ocean floor belongs to this plate. Along the plate
boundaries nearly all the movements occur; within the plates hardly no
deformation and movement happens. Movements near plate boundaries are
characterized by earth quakes and volcanism. Plate boundaries are the weak
zones of the earth's skin.

If we try to reverse the present film of plate tectonics, we could very
well imagine that once both Americas were linked to Europe and Africa.
That was some 150 my years ago. At that time there was a super continent
with the old name of 'Gondwana'. Nearly all the ocean older than 150 my
has disappeared in the great depths.

As I said before, continents are thick. They form thick and solid masses
and it is difficult to split them apart. Something very special must have
happened 150 my ago. That was roughly the moment that both Americas
separated from Europe/Africa; Africa and S. Americ separated from
Antarctica, India started with its drift to the north and found Asia on
its way and also Australia started to move northward, stille moving to the
north and it has still a long way to go before some obstacle will be met.

At some places at present some attacks on continental masses could be
observed. One is the separation of the Arabian subcontinent from the horn
of Africa. The Red Sea is an ocean in statu nascendi. In the middle of the
Red Sea is a spreading ridge present wich stops near Eilath, the tip of
the Sinai peninsula. In the future it either will continue to the east
side of that peninsula right to the north to the Dead Sea and Jordan and
Bekaa valley. The other possibility is the west side to the Suez channel.
The Red Sea ridge is connected in the Indian Ocean to the world wide web
of oceanic ridges.

In that same part of the world is another attack to the African continent.
That same ridge which enters the Red Sea near Aden and Eritrea has another
branch to the south. It is the famous East African Rift that runs from
Eritrea towards the south, connecting all the East African lakes to as
south as Malawi. Africa is slowly splitting apart along this zone. The
eastern part is 'pulled' to a SE direction. Something similar has happened
already earlier. It was the separation of Malagasy. This continental isle
once was situated against the Somalian coast and has moved also to a SE
direction. It is as Africa is slowly peeled.

The East African Rift is already a weakness zone in the thick continental
crust. Earth quakes and volcanic activity is there. A major manifestation
of this latter is the Kilimanjaro. But lots of other volcanoes are
present. As a matter of fact, the East Africa Rift has played an important
role in the very early history of the human race. It is probably also the
main migration route through which the early homonidae migrated to the
north. There was no problem in creating fire there and animals use this
rift valley also as main migration route, so food enough.

There is another famous place where the oceanic spreading ridge 'attacks'
a continent. and where the continent is slowly splitted apart. That place
is in Baja California. A part of the spreading ridge of the Pacific Ocean
continues in the bay between the peninsula of Baja California and Mexico.
The continuation on land of this ridge is known as the 'Valley of ten
thousand smokes'. One can imagine that this must be a very special place,
full of volcanic and seismic activity. It will be a future ocean - like
what is now happening with the Red Sea.

So, what do we have seen so far?

First I like to mention the topographical phenomena of the earth and the
topography of the landscapes that At has sketched for us.
We probably all know the topography of mountain chains. Starting with the
foothills and ending with the summits and all the valleys in between. It
is a sort of vertical meander wich raises to the top. Climbing these
mountains is as we must make two stepsforward (uphill) and one backwards
(downhill), finally reaching the goal.
But wht about mountains with a cleft at the summits? Well, this strange
landscape occurs in the deep oceans. The spreading ridges in the oceans
coincide perfectly with this description. And dear readers, this is a
strange place with permanent volcanic and seismic activity (this
unexpected energy source in the deep and dark waters appears a source for
special life forms).
And lastly, we have seen the rather flat areas of the continents where the
attack from outside by oceanic spreading ridges could cause a deep rift
valley, bounded by large faults which go deep into the earth, breaking the
thick continental crust and allowing the development of volcanoes and

But we have seen more: relatively stable continents with very long
histories and permanently created ocean floors which could never become

Another thing is merging, a term from the business world.
The earth is a closed system for its total mass. There is a mass balance.
That means that the created ocean must be compensated by ocean that
disappears. Sometimes one ocean is growing in expense of another, as is
the case with the Atlantic Ocean which becomes wider and wider whereas the
Pacific Ocean becomes smaller. In the past complete oceans have
disappeared. That is for instance the case with the old Tethys Ocean which
once was the southern border of Europe and Asia, without India (the
Eurasian continent). Yes between India and south China was once a large
ocean. The subcontinent India was once connected with Antarctica (as was
Australia, Africa and S America). India seperated from that continent and
moved northward with an ocean in front if it. Finally the complete ocean
was subducted underneath Asia and India 'collided' against Asia. The
suture between both continents is now the mountain chain of the Himalayas.
India is still moving to the north and it will not surprise me if
Afghanistan will soo also suffer from a major earth quake. Let's hope for
the best of that poor part of our planet.
These sutures are former plate boundaries. From previous cicles of plate
tectonics we could recognise old suture lines. They are the scars on the
skin of the earth and are stille zones of weakness. The East African Rift
for instance is following such old suture line. Large parts of the opening
of the Atlantic Ocean (particularly along the Norwegian and Apalachian
coasts) follow too an old suture line.
Thinkers among you realise that there thus must have existed a previous
'Atlantic' ocean that closed long ago. Yes, that is indeed true.
Geologists have given that historic ocean a historic name: the Iapetus
Ocean (from Greek mythology where Iapetus was the father of Atlantis).

I will mention some aspects of our world of organizations and companies.

1. Fusion or merging of two companies or departments will nearly always
leave a zone of weakness.
2. The process of bringing two companies or departments together means
that what seperated them once has to disappear. Furthermore, this process
is accompanied by lot of heavy 'earthquakes' and explosive volcanism.
3. Seperating/dividing companies or departments will always create space
for new ones and seperation is accompanied by 'earthquakes' and
4. Young landscapes are characterised by high relief: high peaks and deep
valleys, young companies show similar features. Old companies are usually
somewhat smoother.
5. Most friction occurs along the boundaries.

I am afraid that my story was too long, and I doubt if some of you had the
courage to strougle through this long contribution. I was not able to be
more concise in this complex matter that At has introduced.

I hope the best for you,

dr. Leo D. Minnigh
Library Technical University Delft
PO BOX 98, 2600 MG Delft, The Netherlands
Tel.: 31 15 2782226
        Let your thoughts meander towards a sea of ideas.


Leo Minnigh <>

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