Thread: Oceanography

How did the mirror image paleomagnetic stripes form on the ocean floors?

Why can't continental plates subduct?

How does oceanic plate crust form and how is it destroyed?

Are the ocean basins growing or shrinking or maintaining the status quo?

Name the three types of plate boundaries and give examples of each.

Why are earthquakes associated with converging plate boundaries?

Describe how the Hawaiian Islands formed.

homework ?

Definitely.

Oceantheory - give me a convincing reason why I should do your homework for you and I might just help you out.

Seriously - people asking for help with homework don't really bug me but people who just post their entire homework assignment, don't even try it themselves, and don't even post so much as a "Hey guys I am stuck on such and such. I was able to answer this and that but am really stuck on this particular thing" do.
People like that I have no problem helping.
People like this, quit being lazy and do your own damn homework. It's probably all in your freaking textbook and if not those aren't the most difficult questions in the world to find answers to online.

The thing is, he probably got some other mug somewhere to do it for him.

Thats the internet for ya!

Well, I can say that sure wasn't the reply I was expecting. Yes, it is homework. However, it is an assignment with 50 questions in this chapter. I only posted the 7 I needed help with. I don't necessarly need the answers, maybe just help finding the answers. I looked in my book, and I researched the internet before I posted these questions. It would be much easier if I could find these answers myself, instead of going to the lengths of posting them.

I am sorry if this offended some people. I am simply looking for the answers. Once I know the answers I will be able to answer them correctly on the test and final exam.

I suppose I shouldn't use this forum any longer for this?

Maybe if you made that your introduction , people may have helped more.

Originally Posted by oceantheory

How did the mirror image paleomagnetic stripes form on the ocean floors?

As plates move apart, splitting at the mid ocean ridges, lava is erupted. Magnetic crystals in this magma align themselves with the Earth's magnetic field as the lava solidifies. Peridoically the Earth's mabgentic field reverses, so that roughly parallel bands of alternately magnetised rocks are found on both sides of the mid ocean ridge.

Originally Posted by oceantheory

Why can't continental plates subduct?

Continental plates are of lighter material than the mantle or the oceanic plates so they tend to 'float' at the surface.

Originally Posted by oceantheory

How does oceanic plate crust form and how is it destroyed?

As noted above lava is erupted (or magma intruded) at the mid ocean ridges. It is destroyed at subduction zones, where the oceanic plates are dragged back into the mantle by convection currents.

Originally Posted by oceantheory

Are the ocean basins growing or shrinking or maintaining the status quo?

The ocean basins are probably decreasing in size very slowly. this is not necessarily the answer you will find in text books. However, the mantle is progressively depleted in the lighter components that make up continental masses, so that the continets are slowly growing at the expense of the oceans.


Run out of time. That should help you.

http://www.newgeology.us/presentation25.html

Seafloor spreading, in combination with global magnetic reversals, is supposed to produce the alternating bands of slightly higher and lower magnetic intensity on either side of ocean ridges. However, linear magnetic anomalies are known from only 70% of the seismically active midocean ridges, and the diagrams of symmetrical, parallel, linear bands of anomalies displayed in many plate-tectonics publications bear little resemblance to reality.....Correlations between magnetic stripes on either side of a ridge or in different parts of the ocean have been largely qualitative and subjective, and are therefore highly suspect.