Earth Quake Concept?

Hi AH;

I agree with your summation, that it's earth's core that drives tectonic plate movements and earthquakes, what I am alluding to is, if the earth's crust rises in temperature is the crust more free to be driven? I agree that the earth temperature is slowly falling, but would global warming effect the rate?

I see internal temperature being driven by compression, caused by gravity. And external influences by the Milankovitch_cycles . Thank you for your input.

Regards JD.

One would wonder if there has been any investigation into whether each earthquake which is a result of the sliding of the plates results in less surface area of the plates interacting and opposing each other, less of a coefficient of friction between the opposing plates due to wearing down of the surfaces and therefore less resistance to subsequent movement causing the next earthquake and perhaps of a greater intensity. The resulting tsunami from the recent Japanese earthquake must have been the result of greatly more significant movement that has happened for quite a while.

You may find some interesting patterns in the historical data. Lots of statistics and records found here.

I looked at magnitude 8 or greater worldwide since 1900, averaging 1 per year, and varying by decade - the 2000's decade was certainly a bad one. But the second worst on the list is the 1940's. The 1990's and '80's were not bad at all, so there's no visible trend to show anything like a steady increase in high magnitude earthquakes. I'm not sure what the deglaciation time frame is, afaik it didn't make news before the last decade, so it's not impossible that the 2000's decade is the beginning of the expected effect. I guess the bottom line is, time will tell. ???? If there is no significant effect from deglaciation, I would expect the number of big quakes in the present decade to drop below 10.

quakes mag 8 or larger by decade:
1900 9
1910 8
1920 6
1930 7
1940 11
1950 7
1960 7
1970 7
1980 4

1990 6

2000 13

http://earthquake.usgs.gov/earthquakes/eqarchives/year/mag8/magnitude8_1900_date.php

Thanks, that is a very interesting website. Very informative.

Hi Artsmith;

Nice research, not much evidence for a thermal driving force, though one would have thought that seasonal heating and cooling of the earth's crust causing expansion and contract would have some effect at the point that the tectonic plates slide over each other? But as stated by AH, heat from the sun has minimal effect. The reason this question sprung to mind was the possibility Fukushima power plant could go into a melt down, and that would be a lot of heat sinking into the ground? With possible unknown consequences if heat could effect the situation? But this is only a concept, and not having much credibility should not lead anywhere.

Regards JD.

Maybe the drop in the 50's and 60's was due to atomic testing keeping the faults jarred up regularly (and the rads up regularly)

I wouldn't think de-glaciation is a factor, considering the general mass, depth and density of the crust compared to a few miles if ice.

Nice research - another 'stilted bit of journalistic hysteria', bites the dust.

No. De-glaciation isn't a factor, for the reasons you mentioned. On the other hand, the Himalayas are a factor, as far as weight on the crust goes.

There is a set of concepts, largely missing in a number of 'quake' threads.

'Continental drift' from mid Atlantic 'growth' through to subduction - which is what this quake is due to.

So: why do contents drift?

It would help if you had some foundry experience and had watched slag behaviour on molten metal, but ships and water is a good enough thing to ponder.

In principle: If something is 'floating' it displaces fluid. If it is higher above, it is sticking down further below.

These sticking down bumps are what drag thick slag about on thermal currents in the molten metal. Pushed apart, allows thin slag to form. Pushed together, thin slag is driven under the thick stuff. The higher the thick, the deeper it sinks.

If is too thick to subduct, it crumples (Himalayas)

That crumple will stick proportionally down.

Earth is a floating slag system, huge, slow, but relentless.

(Naturally I blame school books for showing it all as a neat set of 'smooth' spheres)

_{[Much in the way they show the atmosphere as 2000 miles thick]}

What I'm really curious about is "What makes the core operates that way?" Is it more like that of the sun or other stars(fusion or fission), or some other process, we do not know yet?

Well, no one has been down there except Arne Saknussemm and a handful of others. Maybe its those giant mushrooms... I digress.

The core's heat is due to the early formation of the planet. Earth was a complete molten ball in the very early days of the solar system. This was due to the heat from accretion as the Earth formed, from extraterrestrial bombardment (the accumulation of material over time), frictional heating, and the force of gravity squeezing it all together.

The core is not a star, like our Sun. Every planet here is too small in mass to self-ignite like the Sun. However, it is believed that radioactive decay does play an important part in the core's temperature.

Why is the core still so hot? Well, it is pretty massive and it has a lot of insulator surrounding it for one thing. The only channels out for heat are either conductive or convective. Not much magma makes its way out and the mantle and crust act like a very good blanket.

But how come then that mercury and venus or mars, did not have the same consequence than the earth considering cooling in the region they orbit a little more slower than the earth? Does that mean that those planets were a little bit older than the earth? That they have spent their molten lava over time, then the forming of the earth came.

Its weird, you know. Comparing Earth to other planets would mean your explanation above on this phenomena would be inconsistent and vague.

Out of the planets on the solar system, Earth is pretty much different because of that.

How would then explain that?

I am not an expert, but speculation is that Earth is much larger and has greater mass, which translates to a much higher internal pressure at the core, thus more frictional heat at the core.

One trait of a molten core is its magnetic field, generated by the dynamic motion of the liquid core. Earth has a pretty robust field, but the rest of the inner planets have very little magnetic fields. This leads us to believe that, at least, Mercury and Mars must have a relatively cooler core with little dynamic movement.

The curious exception may be Venus. Mars and clearly Mercury are much smaller than Earth, but what about Venus? Venus is of similar, but slightly smaller size. One would expect a magnetic field generated by a molten core there, but we do not detect one.

The best theory as to why Venus lacks the magnetic field that Earth posses has to do with the dense atmosphere of Venus. That atmosphere locks in intense heat (greater than 300° C) at the surface.

The high surface temperature may retard the dynamic motion of the core due to a smaller temperature differential along the planet's interior, thus reducing or eliminating a magnetic field.

We have yet to put a spacecraft on the surface with seismic transponders to determine the structure of the planet, so we can only speculate as to the makeup. The best theory supports a similar interior structure to Earth - core, mantle, and crust. There is evidence of volcanos on Venus, but we don't know if any are still active. We will have to wait and see if Japan's latest probe can be brought back to life to fulfill its mission for searching for active volcanism.

For clarity, Venus does have a magnetic field that is weak, but is generated by an induced magnetosphere as a result of the solar wind.

There are a number of planned and current robotic missions to Venus in the next decade. Perhaps more pieces of the puzzle will be gleaned by these missions.

It's suspected that the reason for the low magnetic field on Venus is due to its supposed lack of a solid inner core, which the earth does have (almost the size of our moon, much of it being nickel). Venus has a much slower rotation than the earth, and that was thought for quite some time to be the reason for the low magnetic field. Nowadays, the lack of a solid core theory is gaining popularity.

But there's no doubt that Venus is a bit odd, with a somewhat unconventional history.

Al Gore and hot air...Very Good!

I agree with AH's comments (though, the mantle directly drives plate tectonics as it conducts heat upward from the core; but that's a minor point; the whole process is very complicated.)

Japan is particularly susceptible to earthquakes because it sits at the intersection of FOUR tectonic plates. It is essentially surrounded by subduction zones.

"If you ask Al Gore it is over a million degrees just below the crust. Likely this is where he gets his hot air."

Classic! AH

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JDR, most of 'warming' to date has gone into melting ice, faster ocean currents and busier weather. The actual rise is a few degrees in the biosphere. This is 'insignificant' in terms of the body of the planet.

What is going on is 'per-normal' tectonic process, which by it's nature is 'stick and release' - so tends to come in cycles - as does volcanic activity.

It's relentless and more powerful than anything mankind could do/neutralize/resist.

Perhaps the main difference is more people are aware of these events due to the internet 'short circuiting' the traditional decisions of media to 'tell us what they think we need to know'.

I think the Earth woulod protect itself with Tidal Wave washing cooling techniques.ds

Speaking of Tidal Waves .I was hoping someone in the HIgh Seas fishing industry

with old unuseable Fishing nets might be interested in finding the Garbage Float

out on the Ocean and throw some old nets over it and haul it to the nearest

and largest deserted Rock Island and Catapult them onto the Island Rocks as a

Landfill and then send Seals with rock climbing equipment to Hammer the nets full of

the floating debris to the Rocks with the large pegs used to climb rocks with. Who

needs the rocky Island for anything else if its out there ,until its been

leveled out it cant be built on or used by hardly any animals.ds

ds, the "float" is not a raft of floating garbage. It's not concentrated in that way. Nor, for the most part, is it composed of pieces that are big enough to be captured by fishing nets. The pieces are spread out. You can't even see it, if you were to be in the middle of it. The pieces are all in the same general area, but they are not in contact with each other. This subject has already been covered in another thread.