Download Its report about Plate-Tectonics Report made by: Robbert van

Its report about Plate-Tectonics
Everything about the students’ experiences, things they have learnt
and their experiment.
Report made by: Robbert van Kempen
Members of the Group:
Martijn Otten, Ronald van ’t Veld, Martijn
Beekveldt & Robbert van Kempen
Sience4u project
May 2007
Introduction
During the last few weeks the sience4u project took place. We, as one of the
research groups, worked with a lot of fun at
the subject: “Plate tectonics”. A couple of times we traveled by train to the
VU of Amsterdam. At the department of earth sciences we learnt everything
about the movements of plates, where the earth-crust’s has been
constructed of. We were also informed about the way of how to simulate
geological processes. At Tuesday the 17th of April the big simulating
experiment kept us busy for the whole day. In this report we show you the
things we have learnt and everything about our big simulating experiment.
During this research project we worked in the “Tec Lab” of the VU.
The research-group
From left to the right; Ronald, Robbert and Marijn
Background information
Before we will show you what we have researched, we give you a short summary about the
things we have learnt about “plate tectonics”.
• Plate tectonics
The outermost part of the earth’s interior is made up of two layers: above is the
lithosphere, and below the astenosphere. The lithosphere consist of plates wich move:
Plate tectonics. Plate tectonics is a theory of geology that has been developed to explain
the observed evidence for a large scale motions of the earth’s lithosphere (or the
earth’crust).
Boundaries
The lithospheric plates
ride on the asthenosphere.
These plates move in
relation to one another at
one of three types of plate
boundaries: convergent or
collision boundaries,
divergent or spreading
boundaries, and transform
boundaries. Earthquakes,
volcanic activity,
mountain-building, and
oceanic trench formation
occur along plate
boundaries. The everage
speed of the plates is
typically at speeds of 0.66
to 8.50 centimeters per
year.
The tectonic plates of the world and their moves.
Divergent
Convergent
Transform
Convection
The plates are able to move because of
the flowings in the asthenosphere. Hot
and liquid stones rise from the core, as
the have a lower density through the high
temperature. Than the liquid stones cool
down and move back to the core; a
convection. These flowings drag the
plates along, wich are driving on this
asthenosphere (see picture).
www.aardwetenschappen.vu
Phrasing
During this project we worked to the answer of one question;
“How will the stones in the earth´s crust transform if two plates are pressed together?”
Hypothesis
We expected when the two continental plates collide, you wil get a situation like this:
The forces of the moving plate (the arrow at the picture) are horizontal. It is not possible to
move the sand into that direction, there is a to big mass of sand. That is why the forces
‘escape’ upwards, there is a much lesser mass. At the picture you see the diagonal breaks.
Now, the sand will be driven upwards too, so you will get a number of plateaus. As the
plateaus will move over the remaining sand, the ‘mountain’ will be higher and higher.
The plateaus will be big, because we use a smooth underground (in one time a big shifting).
Application of the technique we used in reality (see working-method)
Our technique of modelling and simulating is also used into the oil- and gas-industry. For
locating the pressence of oil or gas, the made test drills. Wenn you look at the picture beneath;
we ask you a question: “Were will you find more oil, at point A or point B, if the oil is in the
pink layer?” Of course will it be more profitable te make a test drill at point A, won’t it? Since
at this point A you will find the pink layer twice. That’s why these industries use this
technique. Researchers just like us, use this information only for research.
A
B
Working-method
-We worked with an model, wich help us to investigate the geological process. This model is
used to reproduce natural observations and to suggested driving mechaniscms for tectonics
processes. This way of modelling is a little time consuming and a low cost modelling
technique. With this model we reproduce the movements of two continental plates wich move
towards each other.
- The model is built with well sorted fine-gruined dry quartz sand with grain
diameter ≤0,300 mm and a grain density of 1500 kg/m³. We used some different kinds of
colours, since you will get a very clear result. The silicon putty (grey layer) is for the basiclayer, because it reacts well to the forces wich are at this model.
The angle of 1,50º is an experimental aspect. But, in reality, plates who move towards each
another, couldn’t always be flat at the bottom.
-The speed of the plate (vertical), who moves the sand forwards, is about 2,00 cm/ hour. Of
course, it’s a much higher speed than the everage speed of the real tectonical plates. These
plates move with a speed of 2,00 cm/ a year!
At this illustration you see a the slice of the different layers of the model.
The structure (Beneath-above):
1. silicon putty
2. thin black layer
3. thick white layer
4. thin black layer
5. thick pink layer
6.
7.
8.
9.
thin black layer
thick white layer
thin black layer
thin blue layer
Working at the model. With sieves we
put the sand carefully at the right place.
At this way we create layer after layer.
At this illustration a black layer is
alomost finished.
Results
During the test we took every ten minutes a photo of the changing surface of the model. At
this picture beneath (at the left, because the mountain at the right is not the cause of the
‘moving plate’ of the left side) you see the ever increasing ´mountain´.
1.
6.
2.
7.
3.
4.
5.
8.
9.
10.
-With these pictures we have global seen the growning ´mountain´. But at this way you can
not see the inside, the structures, in the sand. That´s why we have pack the whole model.
After that we moisten the sand to get a solid mass.
-With making a section of the model you see the sand layers wich have been changed through
the forces between the ´plates´wich have been pressed together. It gives us a very good
impress of the changes in the lithosphere.
The section of the model.
The diagonal breaks, accentuated, are very clearly.
Conclusion
The stones in the earth´s crust transform, if two plates are pressed together, a lot.
The horizontal forces are unable to move the sand into the horizontal direction, there is a to
big mass of sand. That is why the forces ‘escape’ upwards, there is a much lesser mass. In our
results you see the diagonal breaks. The diagonal breaks you get are the cause of a very
creased stone. Through the pushing forces the stone is concentrated on one place; there is talk
of mountain-building.
Altough every situation where two plates are pressed together is different. So to know how
the stones in the earth’s crust transform, you have to simulate the situation with a model time
and time again.
Acknowledgements
We, Robbert van Kempen, Martijn Otten, Ronald van ‘t Veld and Martijn Beekveldt, would
thank all people who helped us with this fantastic Sience4U project:
• -Dr Bernd Andeweg, who helped us during our whole research-work at the VU of
Amsterdam
• -Stefan Luth and Arno Versteeg; PhD students, they helped us during the big
experiment
• Our escorts Rutger and Pol
• Mr. Bakker, the teacher who escorted us too.
• The schools Stedelijk Gymnasium Leiden, Da Vinci College and the Rijnlands
Lyceum, wich made this project possible.
And finally.....
We want to tell you we have enjoyed this project very much. It was great to work at the real
sientific way and we have learnt many new things. We are glad that our schools offered us
this challanging chance.
Researcher Robbert van Kempen is working at the “Results”.