This is the second day of Tectonic and Lithosphere Dynamics course. I’m still excited by the lecturer. His name is Dr. Graeme Eagles, a graduated Ph.D from Leeds University. He teaches through the some slides that show me many differences of lectures in my last university, my lovely ITB. He is passionate people to tell about Geodynamics of Earth. I love these questions:
(1) Why do the plates move about?
(2) Why mantle convection happened?
(3) Which one the first one: continental crust of oceanic crust?
(4) How come the flood basalt occurred in short space of time?
(5) What is differences of flood basalt and Island Chain, say Hawaiian Islands..?
(6) What is control of the angle of subduction lithosphere?
The most important question is like this: So plate tectonics depends on plate boundaries, because this is where its driving forces are generated. But what makes plate boundaries?
Let me know if you have some thoughts…
What ever your languages, that’s fine, let me know in Bahasa Indonesia, Sundanese, Bataknese..as long as I can understand what do you mean… Cheers..
Hi Dumex,
I think your issues are the fundamental on Geodynamics studies. At this time I would like to give some comment, hopefully it is helping you.
1. Why do plate move about? …. I am not sure what your point at this issue but when plate moving there must be driving forces there. And the direction of the movement depends on the interaction between the plates, which one is the faster respectively to the others.
2. Why mantel convection happened? … Because in mantle there is radioactive elements, which periodically decay and cause heat release and this process same with boiling water.
3. Which is the first one; continental or oceanic? …. This issue is related with the composition of continental and oceanic. We know that oceanic is more on basaltic and the continental more on granites. Looking at the chemical composition, the first one supposed to be is oceanic. Because from basaltic become granites need 1000 – 3000 year in crystallization process.
4. How come the flood basalt occurred in short space of time? … At this issue I am also not got the point, but as I know that flood basalt is a trap of magma. The trap could be magma chamber which is usually located at the continent.
5. What is the difference flood basalt with island chain? … The differences on the forming way of flood basalt and island chain (island arc).
6. What is the control of the lithosphere subduction angle? …. The controls are velocities and the density of the subductive plate.
“So plate tectonics depends on plate boundaries, because this is where its driving forces are generated. But what makes plate boundaries?”
There are three types of plate boundaries, and I believed that you already know about that. Forces that needed to form these three type boundaries are friction, gravitational and external forces.
I am so sorry if my word is inconvenient to you. Take care, God Bless You.
Sincerely yours,
Jhonny
By: Jhonny on October 1, 2008
at 11:35 am
wow…..tough question….
but finally I can find the answer….it’s simple…
want to know…??? just read the comment right above mine….quite similar….although different in words, but the ideas are similar….
hahahahha……
*gak penteeeennngggg comment nya…..
By: Jhon Wood on October 2, 2008
at 2:05 am
Jhonny…I really appreciate your thoughts, excellent. Thanks.
for number 1, if you didn’t get my point..I’m thinking about who propagates plate to move? and for what its moving? to accomodate something…?
I’ve being excited for no.3.. So do you mean the first one is oceanic crust? and its composition one day will be changed to be a continental crust?
for no.4, I’m thinking flood basalt..how to produce the large volume of basalt in a very short space of time..? (short related to geologic time scale yah…)
Could you explain more for no.6..? thanks
…and for the last question..what kind of external forces?
I’m so sorry if my questions are confusing a while..ok. Thanks a lot.
Seems to be a very good discussion with you.
GBU.
By: dumexpasaribu on October 2, 2008
at 7:52 pm
Jhon Johanes Wood.. (Another Jhon hat tried to have a same thought with another Jhon…[Jhonny Xu])
You didn’t give me inputs.. come on, you can answer those questions..
I’m waiting…thanks. GBU.
By: dumexpasaribu on October 2, 2008
at 7:56 pm
Hi Dumex,
for number 1, if you didn’t get my point..I’m thinking about who propagates plate to move? and for what its moving? to accomodate something…?
……. (Yup, earth also needs equilibrium, If at some place happened subduction, must be the other place happened extension. So the plate moves to accommodate something? Absolutely, until it reach some equilibrium, but when that time come, we don’t know as long as the earth rotate I don’t think that time will come.)
I’ve being excited for no.3.. So do you mean the first one is oceanic crust? and its composition one day will be changed to be a continental crust?
……. (Yup, actually I don’t have any reference that states it clearly. Composition here is referring to magma, but there still need some more explanations and research)
for no.4, I’m thinking flood basalt..how to produce the large volume of basalt in a very short space of time..? (Short related to geologic time scale yah…)
…….. (By referring to the definition of flood basalt it self, I thinks it depends on magma rate and also the fissure or conduit to the surface. Ya may be JJW could explain it better?)
Could you explain more for no.6..? thanks
……. (When the movement of the convergence plate faster, then the subduction will have low angle subduction and when the movement of the convergence plate slow, then the subduction will have high angle.
Same with the density, it depends on the age of the subducted oceanic plate, if the subducted oceanic plate old, so the density must be high and the subduction angle become high too and the reverse one if the subducted oceanic plate young, the subduction angle become low.)
…and for the last question..what kind of external forces?
…… (One example of the external forces; tidal (ocean loading) it depends on Moon gravitation (the external force outside of the earth.)
Thanks,
Jhonny
By: Jhonny on October 3, 2008
at 3:17 am
Hi ito Dumex, How do you do? anyway, I don’t find the answer but I’m sure you’ll find the right answer soon….hehe3x. Gbu
By: Busmin Silaen on October 4, 2008
at 3:30 am
Bang Busmin.. thanks, I’m sorry if all my questions are related to geology
God will give the answer, right? Cheers yah..
By: Dumex Pasaribu on October 4, 2008
at 7:01 am
Yes, God will make it complete.
By: Busmin Silaen on October 13, 2008
at 4:39 am
Hi iban…..hehehe…..kita pariban kan..?? (ngarep mode on)
pertama aku mencoba menyusun ulang pertanyaan mu….biar lebih enak jawab nya….
so…the question will be like this…
(1) Which one the first one: continental crust of oceanic crust?
(2) Why do the plates move about?
(3) Why mantle convection happened?
(4) What makes plate boundaries?
(5) How come the flood basalt occurred in short space of time?
(6) What is control of the angle of subduction lithosphere?
(7) What is differences of flood basalt and Island Chain, say Hawaiian Islands..?
Then…i’ll try to answer on my next post….
By: Jhon Johanes Wood on October 20, 2008
at 4:16 am