♪ [Music Playing] ♪♪ 
>> Dr. Wahby: Plate tectonics
a major paradigm shifts.
This is revolution.
And revolution in the butt
and the core of the air.
And it's very proper to
have this as part of the first
Eastern Illinois University in
Charleston, Illinois, the first
Symposium in
Technology and Science.
And we chose the theme for that
symposium to be revolutions
in science and
technology paradigms.
What a coincidence to have
the same Tectonic thing.
We don't want anything to happen
today to anywhere in the world,
but I would see what this
paradigm shift leads to.
Dr. Steven Daniels, the chair of
the physics is working with me
in this putting this together.
He couldn't be here today, but
it's my pleasure to introduce
our esteemed speaker,
Dr. Katie Lewandowski.
You say it.
>> Dr. Lewandowsi: Lewandowski.
>> Dr. Wahby:
Lewandowski, right?
Did I say it right?
OK, please join me in
welcoming Dr. Lewandowski.
[Applause] 
>> Dr. Lewandowsi: I am going
to talk a little bit about plate
tectonics, which is, it
explains so many things
in earth sciences.
And so its a concept that
we teach in all of our intro
classes, and it has a very
interesting story as to how
it came to be discovered
and accepted.
In preparing for this talk, I
was reading Naomi Oreske's
book of Essays called Plate
Tectonics: An Insider's History
of the Modern
Theory of the Earth".
It's really interesting.
She is a historian of science, a
historian in geology, and it has
a bunch of essays written by
people who were there at the
time, and it's their memories
of how things happened.
And one of the things she
says "that I thought really
captured how this revolution
happened, is that research
thrives where smart people can
work together and share data
and ideas."
And it really was a
gigantic project.
It was many people were working
on trying to understand the
earth's processes and their
expression, and I don't know
that it would have come to
light, if there weren't so many
people working on it.
So, at first I thought that
I would tell you what plate
tectonics is because many of
you are chemists, and so I don't
know if you know much
about plate tectonics.
It's a global and unifying
theory within our discipline.
I'm a micro paleontologist, and
I prefer to plate tectonics all
the time, even though most
of the evidence comes from
geophysicists, and
electrologists, people that
study the interior of the earth,
really, and basically it says
that there are rigid
lithospheric plates which are
the crust, and those rigid
lithospheric plates move over a
plastic asthenosphere, which
is the, essentially the mantle.
And it has kind of a
consistency of silly putty, so
it flows, but it can also break.
And the thing that drives the
movement of the plates and you
know, you probably all know
the earth has not always had
the same configuration.
That there were times in the
past where there have been
supercontinents, and maybe
multiples times in the past
where there had been
supercontinents, and it's really
the mantle convection, so it's
really like if you think about
it like a boiling pot of water.
You heat it up and then you have
convection cells within your
boiling pot of water, the water
on the bottom heats up and as it
becomes less dense, it moves up
to the top and you have these
cells, and it's the
same idea in the mantle.
You have, you know, the
fluid is actually different.
And like I said, it's a theory
that is used by all of the
scientists.
So, like I said, I study
tiny little critters
that live on the sea floor, and
I use plate tectonics all the
time to explain some of
the things that I see.
I want to talk both about how it
was discovered, and some of the
interesting human
stories associated with it.
It was essentially developed
over the course of the
twentieth century.
It started out really, with
Alfred Wegener's theory
of continental drift, which was
rejected by especially by North
American scientists.
And then eventually it was
accepted in as the theory of
plate tectonics after much more
evidence was collected, and much
more data look at in
that late to mid-sixties.
Like I said, there were
many, many scientists that were
involved in the project,
although there were a few women
and no African Americans really
involved in it because of the
times, and because many of
these scientists had personal
connections to each other.
And there were a few
institutions, so, while there
were many scientists,
most of them were from four
institutions.
They were from Cambridge
in Britain, from Columbia
University's Lemont Geological
Observity, it's now known as
Lemon-Dougherty Geological
Observatory, the University of
California Scripts Institute
of Oceanography and
Princeton University.
And so I'm going to highlight
some of the scientists that
worked on this, I can't talk
about all of them, because
there are too many.
Like I said, it's a
story of data sharing.
And so, all of these people were
working to try to figure out
what was going on in the oceans,
what made the ocean basins, what
was that, what were mid-ocean
ridges, and why are they there?
What are trenches?
And so, because they were
sharing their data, there was a
rapid development of ideas,
because the more you talk to
people, and talk about their
ideas, a lot of times the more
rapid development of ideas.
And it's really a story of
effective interpretation of
data.
One of the reasons that
this theory was developed,
was because there was a lot of
federal funding of sciences.
There was funding to begin with,
you know, in the early part of
the twentieth century, there was
funding to discover, to really
to understand how sound waves
worked in the ocean, because
they wanted to be able
to detect submarines.
And to be able to exploit that,
so it was a military project.
There were other
reasons as well.
So there was lots of
funding of earth science.
Of course, World War II started
there was even more interest to
find German U-Boats, and things
like that, and to be able to
hide within shadow zones.
And so that's one reason
there was a lot of funding.
Also, because of the GI Bill
right after the war, there were
a lot more people going to
college, and there were a lot
more people pursuing higher
education and so that is
probably another
contributor to this.
And, of course, military funding
of scientific research for
national security is going
to involve large labs, and
team-oriented promotions,
and so that is one thing
that supported this.
You know, there were a few
institutions with many people,
because there were senior
scientists working on it, and
then there were grad students
working on it as well, as many
of you were probably aware.
The Office of Naval Research
funded a lot of the studies and
they funded studies at the Wood
Hall Oceanographic Institution
as well as at Scripps in
California, and Lemont in
New York.
And really the idea was
to understand the physical
oceanography, to look at
underwater sound, do echo
sounding and things like that,
to be able to image the sea
floor, what did it look like, I
mean, to us, it just looks like
you would imagine that oh, it's
just you can see the water, but
you don't know what it looks
like down there, but there are
hills and valleys, and
things down there.
And they wanted to be able
to use sound, to use the echo
sounding, and things like that
to be able to image it, as well
as being able to look at
magnetics, people discovered
that there are these weird
patterns on the ocean floor
where you have magnetic
alignment of salts and even of
sediments that contain magnetic
minerals and they switch.
You have kind of a
zebra pattern that occurs.
It's you know, they show it in
text books and it looks black
and white, black and white,
and its symmetrical along the
mid-ocean ridge, and so
they wanted to understand
why, what caused that,
and what does that tell us?
As well as, bathymetry is really
understanding what the heights
and depths of the
ocean look like.
Like I said, it is a unified
global theory, and it is
data driven.
The data and the data were
collected as a result of the
oceanographic expeditions.
Oceanographic expeditions
are very, very expensive.
It's very expensive to operate
a boat, or operate a ship.
You have to have a crew, you
have to have scientists on
board, you often have all kinds
of gadgets, and do-hickeys that
you are going to try to
collect data with, and so it's
logistically very complicated to
run these kinds of expeditions.
People usually work basically
around the clock, the scientists
work on twelve-hour shifts,
because they have to collect
as much as they can, and
use the money wisely.
Basically, we'll talk a little
bit about continental drift, in
a minute, but the years from
1945 to 1970 were really a time
when evidence was being gathered
to support plate tectonics.
As I said before, the
bathymetric data and
understanding what the sea-floor
looked like, how diverse things
were on the sea-floor, and
then as well as understanding
everything about the oceans.
They didn't really know
that much about the oceans.
People had been crossing the
oceans for thousands of years,
but to really understand what
are, what is going on with
chemical and physical
properties, what are air-sea
interactions, and like I said,
what's going on magnetically,
and as far as gravity has to go,
has to do with the sea floor.
I wanted to go back a little
ways, and talk about some
of the evidence that comes
from a long time ago.
Even as far back, as far as that
goes, Leonardo Di Vinci in the
fifteenth century had noticed
that you know there are fossils
upon land and how
did they get there?
So, there were people who had
realized that probably things
weren't exactly
as they are today.
In the sixteenth century, there
were scientists that had noticed
that if you look at maps and you
compare the fit of continental
edges, that you can fit it
together like a jigsaw puzzle.
And then in the 19th Century,
when Paleontology really took
off, field geologists had
noticed that there were many
fossils in different places that
matched up that are no where
near each other.
And we'll talk about some of
that data when we talk about
continental drift.
And then in the early twentieth
century, Seuss, whom I believe
he was an Austrian, he came up
with this Gondwanaland Theory,
which is kind of the first
theory of supercontinents.
And that is important; the super
continent idea is important to,
particularly to Wegener's
continental drift theory.
So Wegener, and Wegener
was an outsider, he was
not a geologist.
He was a meteorologist, and
this was one of his problems.
This was one reason that people,
the North American Geological
community did not want
him to be part of us.
Because he was a meteorologist.
So he came at this problem from
a paleo climate point of view.
He was looking at, there
were these deposits, there are
glacial deposits that are on
far flung across different
continents, in the southern
hemisphere, and so how did
they get there?
They are in places today where
you wouldn't expect to have
glaciers.
And so he came up with, I
think he published in 1950,
he published his theory
of continental drift.
And basically, a major keystone
of this was Pangaea, and Pangaea
was a super continent that was
basically together about 250
million years ago.
As you can see, most of the
continents are stuck together,
and you have this gigantic,
there's the Tethys Sea up there,
and then the gigantic ocean,
which is the Panthalassa
Ocean.
And some of his evidence for
this, of course, we go back to
the idea of the jigsaw puzzle
fit of the continents, which
some of you probably did a lab
in fifth grade, where you had to
fit them together.
He also looked at mountain
belts, and you could tell that
there are mountain belts.
You know, the Appalachians
actually match up with mountain
belts in Scandinavia,
and in the British Isles.
They are the same age, you can
find the same kind of fossils,
and things like that.
And so, we know that today, we
know that those were together,
and he said, well, maybe
those were actually part of a
continuous mountain
chain in the past.
We can look at fossils,
organisms, that were living,
that and their life habits were
such that they were not able to
cross an ocean, so this
Mosasaurus which is a
crocodile-like reptile, likes to
live in an aquatic environment,
there's no way it would be able
to swim all the way across the
ocean.
And these fossils are found in
both Africa and South America.
So, how do we have evolution of
two of the exact same organisms
on different continents, which
seems like that wouldn't happen,
or is it that these two land
masses were close together,
when these critters were alive,
which seems more likely.
And then the glacial deposits.
And so you can see today,
we looked at these glacial
deposits, we can see glacial
deposits from 300 million years
ago, on Anarctica, Austrailia,
Madagascar, India, Africa, and
South America.
And these places are all, they
are not very close together, and
it seems very weird that
you would have them in India.
But, if we look at, if we fit
all those continents together
and we look at where they were
300 million years ago, we can
see that it makes sense, because
there was a big ice sheet
sitting at the pole at the time.
Unfortunately, North
American scientists hated it.
They thought it was bad science.
They rejected it outright.
There were some
reasons for this.
One is that American science
believed that there should be
multiple working hypothesis.
Sort of an idea that it was
democracy of ideas, that you
didn't want any one theory
to be, and this is Ruski's
intrepretation of it.
But it seems like it fits.
And so you didn't want any one
theory to be supreme over any
others.
Good science was supposed to
be empirical, inductive, and
modest.
And the theory of continental
drift didn't fit into that.
It was incompatible with the
way that Americans thought about
iscostasy, which is basically
the equilibrium, but between the
lithosphere and the
asthenosphere-- and I'm not
going to go into that with
you guys-- and then this
idea of the legacy of
uniformitarism, which is the
idea that present is
the key to the past.
Well, it doesn't
really fit, does it?
Because we are saying the
continents don't look like they
do today, 300 million years ago.
And so, these were all reasons
why North American scientists
said this is a terrible idea.
We are going to reject this,
plus the fact that he is an
outsider.
And so, it was kind of put to
bed in North America, but people
continued to collect evidence.
One of them is looking at
gravity, which is the idea they
did gravimetric readings over
the oceans and things like that.
There is a density contrast
between rocks in the ocean, the
salts, and then rocks on land,
which are the crustal, the crust
part, the continental crust, is
thicker but it is less dense, so
it sits up, so that's one reason
you have the Himalayas, they are
very, very thick, but they are
less dense, but they also have
this gigantic groove that
extends down into the mantel
to keep them there.
And so gravity is one way
they looked at it, and they were
technological advancements, you
know, gadgets and things like
that, that were developed, to
look at gravity in the oceans.
And so, like I said, submarine
warfare was a major part of
this.
World War II incidentally there
was a lot of funding of American
science at the time.
In order to combat submarine
warfare, because there were a
lot of losses in the
beginning of the war.
They put together a world wide
standard seismograph network
which was a way to collect
seismographic and so looking at
earthquakes and volcanoes and
things like that they could get
an idea of what was
going on in the ocean.
And then again, developments in
geophysics and oceanography, so
development of magnetometers,
things like that, as well as
imaging processes, and then
interpreting the magnetics.
Some of the major contributors
were Harry Hess, who was
actually in the Navy and one
of his jobs while he was in the
Navy, was to echo sound the
Pacific, and he is credited with
the theory of sea floor
spreading, which is the idea
that the mid-ocean ridge
is where the sea floor is
spreading, and the ocean is
getting larger, he published
this along with Robert
Deets and he was from
Princeton University.
Maruice Ewing, who was the
Director of Lemont in New York,
and he collected enormous
amounts of geophysical data
that were interpreted by
many different scientists.
Bruce Heezen, who mapped the
ocean ridges in the 1950's.
He was a geologist; he was at
Columbia at Lemont and the Mari
Tharp, the only woman that
we are going to mention.
And she just died recently, over
the last five years, or so, and
she started out as Ewing's
research assistant, but then
she spent most of her career
working for Bruce Heezen.
And they, a lot of the data
that was collected, was actually
classified, and so one of the
things that they did was they
figured out a clever way to
get around publishing the data.
They did an artistic impression.
They made a map, this is
hand-drawn, and this is so
they got away with doing this,
because it was an artistic
impression, even though
it is, it's accurate.
This is actually in my
oceanography textbook,
I refer to this all the time.
You can see the
features, and the ocean.
You can see the oceanic
plateaus, you can see
the ridges.
You can see the transformed
boundaries and things like that.
It's phenomenal.
Vine and Matthews did a lot of
work on the magnetic data that
comes from the sea floor as
well as Lawrence Moorely.
They sort of publish at the same
time, and so now it's referred
to as the Moorely,
Vine and Matthews theory.
And then J. Tuso Wilson,
who was a Canadian, and
he really discovered transformed
boundaries, and began to sort
of publish on what
transformed faults were.
And so the evidence, as I said,
and I'll wrap it up, is gravity
data, the earth magnetic field,
the paleomagnetism, sea floor
mapping, they did a lot of
earthquake studies, and the heat
flow, because the heat flow was
greater at the ridges where you
are erupting new basalt, whereas
it's less in other places.
I'm just going to skip, because
of time; I'm not going to go
into the paleomagnetism,
but just a little bit.
Paleomagnetism we can look at
rocks and they have a magnetic
signature, particularly basalts,
and some sediments that are,
that have little tiny pieces
of magnetic minerals in them.
And so when the basalts cool,
they cool through a point known
as the Curie point, and the
minerals will align according to
the magnetic field
that exists at that time.
And it's going to look different
at different latitudes, so we
can actually use that to
reconstruct where those rocks
were when they were erupted.
And so that's a really
powerful tool for us.
We can see that oh, you know,
those rocks were at the equator,
or they were up at
the Poles at the time.
And so that can help us to
reconstruct the supercontinents,
or where the
continents were in the past.
We can also look
at a polar wander.
You can see from here, if we
look at polar wander data, this
is from Europe, and this is from
North America, and it doesn't
match up, but if we actually
move the continents to where
they were 300 million
years ago, they match up.
And so again, just
using the magnetic data.
This is the stripes
that i was referring to.
And so they knew that there
were stripes and it has a zebra
pattern so you've got white and
then in this case, red, and so
it shows when the rocks are
erupted at the center of the
mid-ocean ridge, they are, they
align to the earth's magnetic
field, and you get this pattern,
so you have normal and reverse,
normal and reverse,
and so on and so forth.
And then it's just more of
the same showing the basically,
showing the basin getting
bigger, earthquake studies and
that gives us an idea of
where the plate boundaries are.
And over time, at divergent
boundaries, you actually will,
these are Wilson cycles, and
so you actually end up with an
entire ocean basin.
So, today, we have drifting
in east Africa, it could
potentially if it continues to
drift, for a long time, it could
potentially be like
the Atlantic ocean.
And then this is just a picture
to show the mantle convection
cycles.
And to end up, I'm a
micro paleontologist.
And I am, I study the little
tiny critters that live on the
sea floor, and I get my samples
from a program that was started
in the late sixties.
And it was started right after
plate tectonics, the theory
plate tectonics was published,
and basically the idea was to go
out and collect more
data on plate tectonics.
It started off as the deep sea
drilling project, and today it's
actually the, they just changed
their name this year, so it's
now the Integrated
Ocean Discovery Project.
And I did my dissertation
samples from cores that were
drilled from that, and I
continued working from
those samples.
And so, this is, it's a unifying
theory, and you know, it's
really changed the way that
we look at science as a whole.
>> Dr. Wahby: Thank you
[Applause]
Well, any questions?
I have twenty questions.
Yes.
Please 
>> I know it took a long
time for this to be accepted.
When would you say it
became a consensus?
Taught in classrooms,
and things like that?
>> Dr. Lewandowsi: You know,
I, Allen, do you, what do you
think?
I mean, it's probably, I don't
know, I mean, by the time I got
there, it was taught in
classrooms, but what do you
think?
>> Alan Baharlou: By the time I
was working with the Ph.D.
it was, 65 so on, so it must
be late fifties, that consensus
reached that.
Parts of the movie, all the
evidence, and earthquakes that
occurred on the plates, which
all the time, those earthquakes
was compatible with the position
of these plates, because they
were against each other
causing the earth to shake.
>> Dr. Wahby: Any
other questions?
Let me ask you something.
How truthful is the popular
way of thinking or image of the
continets and filled with
water in between, like
Hawaii for example,
big mountain, and 
>> Dr. Lewandowsi: Well, Hawaii
is a little bit of a different
situation, because it is a hot
spot, and so, you have some sort
of heat source underneath a
mantle boom or something, which
is heating it up, and then you
have the plate is when you cross
it, and that's why you get
that little dot of islands.
So, that's a little bit of a
different, because that is,
they are basaltic which is
the same material--sort of--
as the ocean floor.
>> Dr. Wahby: So, the
continents are not the same.
>> Dr. Lewandowsi: The
continents are, have a yeah, the
continents have a, the magma is
evolve further, and so it is, we
say that it is granite, it's not
all, but it is, in some places,
so you know the idea that
you have plates where there's
convergence and things like
that, and then that you have
granites beings erupted in some
places like the Sierra Nevada's
and stuff like
that, that is true.
It is accurate.
>> Dr. Wahby: Let me ask
about the earthquake things.
Some places we've known for
centuries for many years that
they are in the belt of
earthquakes-- Japan and others.
But for our [unclear
dialogue] we had something
happening for example in Egypt
in the 1990s where we had
[unclear dialogue].
Is there any explanation
why [unclear dialogue].
>> Dr. Lewandowsi: Well, yeah,
it's always sort of changing.
That's the thing.
That's a slow constant changes,
that's what the plates move on a
scale of centimeters per year,
and so over time, you know,
rifts can fail, and then you'll
have rifting in other places.
And just because of the dynamic
nature of the convection cells
and things like that,
it is going to change.
>> Dr. Wahby: Because when we
were as children, we hear about
the Algerian or the
Oakland earthquake that
happened in the 1960s I
think [unclear dialogue].
And then you have Turkey.
And we are always we grow up,
[unclear dialogue]
>> What is the single most
technologically advantage, like
geologists cherish now?
I mean in those days
people were limited in
the technology to explore.
>> Dr. Lewandowsi: It kind of
depends on what discipline you
are looking at.
Because, you know, a lot of the
data today that is collected in
geology is probably
has to do with isotopes.
And so it's mass
spectrometer work.
Because people want to know
things about oxygen isotopes, or
they want to date things, and
yet you know potassium argon and
its one of the, potassium argon
data was one of the things that
was developed over this time,
and it helped them to be able to
understand the ages of the
basalt in the ocean basin.
>> I didn't mean to bring
chemistry, but chemistry
came out.
>> Dr. Lewandowsi: Yep.
>> Dr. Wahby: Now, if somebody
asks you why is it that you have
geographic north and
magnetic north-- why?
>> Dr. Lewandowsi: Well,
geographic north and maybe the
geographer should answer this
question, the geographic north
has to do with, we just call it
a point at the north, we call it
the North, you know,
just the very top point.
Whereas, magnetic
north actually does move.
>> Dr. Wahby: It's the real one.
This is where iron points,
always.
So why don't we say, ok since
it points to this, why do we
need a geographic, why doesn't
it always point north?
>> Dr. Lewandowsi: I don't know,
I''m not a geophysicist.
>> That's the mathematical
location, so that's where the
lines of longitude
converge, so that's the math.
>> Dr. Wahby: So that's the
math, it just happens to be
there.
Ok.
Any other questions?
Very interesting topic, and
really thank you very much.
[applause]
00:30:58.600,00:00:00.000
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