nealadams wrote:New postby Just A Theory » Dec 06, 2011 6:22 pm
nealadams wrote:
(sigh) Gentlemen (and ladies) Subduction is a GRAVITY-driven process. NOT that the subducting plate is HEAVIER than the asthenosphere,....WHICH is WHERE IT COMES FROMMMMMmmm, ,..at all but, it is more SOLID,.. than the DUCTILE asthenosphere. STIFFER,.... So the DOWNHILL slide FROM THE RIFT''S,.. force, added to the stiffness,..DRIVES the subducting plate into an asthenosphere that purchase was made into 60 MYA as the Australian plate drove upward shattering the Indonesian plate above it.
Best Regards
Neal Adams
Subduction is absolutely not driven by gravity. The driving force is convective currents generated by the heat of the Earth's core.
(sigh) Let us review CONVECTION in a simple lab experiment.
Water is put in a glass beaker or a Pan, and the pan/beaker on a fire.
Let's clarify: Between the core and crust is first the MANTLE,.. then the upper portion of the MANTLE , we call the asthenosphere, which, we are told is LESS DENSE than the Mantle and DUCTILE (from the rising of,...Not 'heat" Because as we know, heat does not "RISE" but molecules. HEATED, RISE. So GASES RISE, making the Asthenosphere DUCTILE.
Up higher these super heated gasses collect under the crust. Scientists tell us that only 4% of the Asthenosphere is LIQUID, and MOST of that is under the rifts,...because the RIFTS are HIGHER than the rest of the ocean floor! (Thinner, younger and pushed up by the super-heated gases.)
Back to our lab experiment. The "FLAME" heats the water, the molecules rush around and RISE to the TOP of the water. Some fly off as steam,..others cool and therefor drop down in a process we call 'convection' to heat up and rise again.
Now we will replace the Beaker or Pot with a PRESSURE COOKER, with a sealed LID. The lid holds the HEATED molecules IN,.. and they do NOT go down,.. they collect at the TOP,.. which is the HOTTEST area. ) Unless we turn the flame up.
On PRESSURE COOKERS there is a relief valve that lets super hot gases out,....not unlike RIFTS!
This is what Earth is, for want of a better, more elitist phrase, a Pressure Cooker! There is NO Bunsen burner under the asthenosphere, which is, in fact cooler. The Super-Heated Gases rise from the Core, through the mantle,(Because that is the only way to go....UP) and through the asthenosphere and into the liquid. molten Basalt collected under the RIFTS,...and there it stays.
This is the Physics of it, and this is how convection works,...and doesn't work.
There are NO convectine currents moving continental plates around, according to Physics FACT!
GRAVITY always works to bring things down,.. no matter how shallow the slant,.. and the GREATEST PRESSURE is at the bottom-most thinest area. Mostly it makes troughs. At the Ring of Fire, because of Australia, it subducts.
Best Regards
Neal Adams
There is so much wrong there.
For most is the fact that a material that is heated does tent to rise. Not gasses, but any material heated will increase in volume and decrease in density. OK now that you're misconception of basic convection, that most people learned the actual mechanism in 6th grade if not before, is corrected want to try that again?
Then again you still apparently think that a solid will spontaneously sink into a fluid that is denser then it.