I read a fair number of scientific papers online. While looking up information about hot springs like Geysers, California, I came across this interesting paper about inner planetary convection. Scientists try to summarize their work using all sorts of imagry and this time tickled my fancy: hot boiling water with things floating in it.
I googled information about convection theories, trying to understand how hot springs develop and what they mean, geologically speaking. I wanted to know if they could trigger rifting and splitting which could cause great volcanic eruptions. This paper amused me and I thought it would be fun to simplify it further for an article:
Physicist, Physics Degree from University of Chicago
First Developed, Mar 1996,
First Published on the Web: Jun 22, 1997
An analogy exists for the movements of Tectonic Plates upon the Mantle convective flows. It is a large kettle of water on a kitchen stove, with a variety of pieces of tissue paper floating on the water.
I love to mess around in my kitchen so I ran there and began seeking things I could use as models representing continents floating on the surface of the earth. Digging around in one of the drawers, I found some plastic cookie cutters I used for many years, baking sugar cookies for the kids. To my immense joy, they make perfect continents!
They had that bumpy/round shape, a star-shape or best of all, the classic 's' shape such as South America or Africa exhibit. On top of all this, they were shaped with a perimeter that made them float like little boats! I decided to use only three of these because if I used more than three, it was too crowded.
I then took out my turkey basting pan because it was both big, shallow and blue. I put in a thermometer to read the temperature and lit the fire.
Click on all pictures to enlarge
The Core has a substantial Iron content, in a very viscous semi-liquid state. The heat from the centrally occurring radioactive fission must pass through this thick layer of Iron Core. Some of the heat is conducted through it, since Iron is a reasonably good conductor of heat. But the present premise suggests that a substantial part of that heat is carried by convective action.
This substantial heat represents a strong driving force which causes the formation and maintenance of a number of convection cells inside the Core. In some locations the Core material, including the Iron, rises (very slowly) toward the surface. When near the outer edge of the Core it moves laterally for some (random) distance as it gives up its convective heat (by conduction and radiation) to the Mantle above it and and the Core material therefore cools. Having cooled, it sinks back down toward the center of the Core to replace the heated material now convectively rising from there.
The result of this is an assortment of individual circulations of the Iron materials in the Core. Each of these circulations' flows are carrying Iron in a closed loop. At least some of those Iron atoms become charged by a variety of natural physical phenomena. The closed loop of circulating Iron has the effect of being like a loop of wire that is carrying electric current.These Core convective cells, therefore, represent a variety of separate very low voltage, VERY high current electric currents in the Core.Each of these loops has its own dynamics and its own orientation. Every circulating electric current creates a resultant magnetic field. The sum total of all these resultant magnetic fields is the magnetic field that we measure at the surface of the Earth.
Electric Arc Furnace - Since the second World War, this has been the standard furnace for melting steel in large quantities. Typical Capacities are 80 to 120 Tonnes. They were generally used as direct replacements for Siemens Open Hearth Furnaces.
Low Voltage, High Current electricity arcs between three large electrodes hung from the lid of the furnace and the metal on the furnace hearth. This produces very intense heating in the centre of the furnace, in a similar way to arc welding.
The heating can be very accurately controlled and as there are no 'products of combustion' (smoke and flame) within the furnace high quality steels are easily produced.
Not just arc welding, electric fences are this way, too. Once upon a time, due to having the largest ox team in the Northeast if not the world, we had to have electric fences or the boys would bust through. Even so, Sparky, our aptly named horse, would chase them through even the charged electric fence.
One day, we had a terrific lightning storm. A lightning bolt hit the mountainside and melted the electric fence and sent large segments of it up into the tree tops. It also melted the fence charger, of course.
Chip and Dale were under the oak tree and jumped so high, they left deep prints in the ground. Oh, and this same bolt of lightning hit me, of course. Right in the chest. Fun.
It doesn't surprise me to read this process is at work in the center of the earth. We also use an arc welder and this is the same principle. Very little electricity (relatively speaking, of course) can heat metal to a very high level and melt it. Thinking about the earth's core as some sort of giant arc welder or electric fence feeding current through channels is most interesting because of reports of 'lightning' during earthquakes at night!
There aren't many such, most people are in bed at night and electrical lights mask this but I was reading about the great New Madrid Earthquake which happened at night.
At Knoxville, the quaking of the earth on the 16th was represented to have lasted more than three minutes. The rattling of the windows and furniture of the houses were such as to awaken almost every family. This was about two in the morning. It was followed, in half an hour, by another, which continued half a minute. Between sunrise and breakfast, three others were felt, of only a few seconds in duration. At the end of the first and longest shock, there were, in a direction due north, two flashes of light, at the interval of about a minute, very much like distant lightning.
A number of witnesses claimed they saw distant lightning. People in the quake zone itself were engulfed in a fine dust and mist which obscured their views but they reported an unearthly light during all this.
The town of St. Louis, in Louisiana, experienced a full proportion of the commotion. Mr. Riddick, being at St. Louis, near the Mississippi, observed to me, that the shocks were preceded by a remarkable calm. The atmosphere was of a dingy and lurid aspect, and gleams and flashes of light were frequently visible around the horizon, in different directions, generally ascending from the earth. Sometimes sounds were heard, like wind rustling thorugh the trees, but not resembling thunder.
Many of these people were quite careful to explain what they saw. Contrary to present beliefs, the attempt at being 'scientific' was very strong in 1800 as we saw with the attempts at rationalism by our own Founding Fathers, people tried hard to use the scientific method when describing natural events.
Being on horseback in Livingston County, Kentucky, Mr. Riddick, on the morning of the 8th of February, was sensible of the earthquake. His horse refused to proceed, and bracing himself on his legs, stood still. The atmosphere was remarkably luminous for some time prior to the shaking of the ground. There was no moonshine; and yet objects could be seen to a considerable distance. On this occasion the brightness was general and did not proceed from any point or spot in the heavens. It was broad and expanded, reaching from the zenith, on every side, toward the horizon. It exhibited no flashes, nor coruscations; but, as long as it lasted, was a diffused illumination of the atmosphere on all sides; but no noise was distinguished until the shaking of the earth began; then the usual rumbling sound was heard.
Closer to the great disruption of the New Madrid earthquake, lighting rising from the earth was witnessed but further afield, the sky was all 'aglow' with a strange light which was probably diffused by the fine dust and steam raised by this massive earthquake.
Very few 9 M earthquakes are witnessed at night on land. The most recent ones were either at sea or in places totally remote from most humans or during daylight. So it is most interesting to read that many witnesses to this event so long ago, report lightning from the earth and a general light illuminating the night which had no moon.
Here is my own experiment with the boiling water, the mist is now so dense, one can barely see the 'continents' moving about. They would clash and then move rapidly away from each other only to bounce back again. The other thing that interested me a lot was the rotation: they didn't move in straight lines but turned around.
Looking at the shape of the continents, one can see this at work which is why so many of them have a shape perfect for rotating. The 's' shape of the isthmus connecting North and South America are echoed by the exact same 's' shape dragged away from South America and Antarctica.
Since the tectonic plates are dragged most efficiently by their extensions sticking down into the Mantle, they are most subject to variations in the flow in those vicinities. Consider a continental plate, which sticks down somewhat to start with. Say that the continent is physically large enough to be above at least two of the inner Mantle convection cells. Say it has two main mountain chains, like North America. Say that the convection cell(s) beneath one of those mountain ranges reverses lateral direction. This would cause an opposite drag on that one chain, which could cause the whole continental plate to rotate (or tear apart, as under the Mid-Atlantic Ridge). In a few thousand years, the continent could be turned completely north to south. This action could also affect adjacent oceanic plates, pushing them around to change their motions. Subduction and the other phenomena associated with Plate Tectonics are well explained by this current premise. This phenomenon, in combination with conventional continental drift, can explain tropical fossils in Antarctica and Alaska, without having to have the Earth do anything that violates Newton's Laws. The Crust of the Earth, or the entire Earth, or the entire Core, doesn't need to reverse rotation or suddenly flip upside down, as some previous theories have implied. It can also explain some geologically and biological evolutionarily rapid changes that traditional theories have trouble with.
I happen to agree with Professor Johnson on this matter: the continents all rotated due to the way convection works. Their queer shapes are often more like the galaxies we see around us. The shape of South America and Africa can be easily explained if one is looking at them as organic entities, spinning in the morass of the upper mantle. Europe and Asia have been warped by crashing into each other so we can't deduce much from their present shape. I would bet India was shaped like Africa or South America before crashing into Asia.
I am betting Australia will gain a more spiral shape as it rotates into Asia. Some geologists think it will move to Alaska but that presumes a straight line and I think Mother Nature hates straight lines, she prefers curves, being female (ahem). The convection that roils underfoot is less potent than a billion years ago, of course. We can see from the recent discovery of deep sea vents, the cracks in the earth's crust lead straight down to some extremely hot and very active zones.
The unexpected discovery 25 years ago of abundant life in the freezing, pitch-black waters of the deep ocean dramatically changed how we think about the requirements for life, said Jim Yoder, director of the Division of Ocean Sciences at the National Science Foundation. "Here was an entire food web that depended on chemical energy from the earth rather than energy from the sun." Yoder said that this is one of the most significant discoveries in oceanography in the last 50 years.
Vents occur where there is volcanic activity. The cracks in the seafloor allow water to percolate through the ocean crust where it is heated by nearby chambers of magma. The super hot water—sometimes 750ºF (400ºC)—dissolves metals and salts as it travels through rocks, eventually rising and gushing out of the hydrothermal vents. These searing vent cocktails are responsible for the chemistry of the world's oceans.
The atmosphere up on the surface of the planet a billion years ago was uninhabitable. The discovery of these vents rewrote the possible history of life on earth. Aside from the nutrients and the heat, the fact that this is closer to the low voltage/high current electricity meant evolution could happen since electricity can jolt shifts in the chemistry of various cells, changes in the RNA sequences, etc. Instead of lightning raining down upon the diffuse surface of the oceans, life took shape perhaps in these close to the mantle zones where the inner electrical processes interacted with the outgassing of various minerals under great pressure and heat.
Throughout the history of geology, the anarchists talking about everything being very fluid would always clash with the conservatives who like a more static model of the earth. But I would suggest, the more one goes back in time, the greater the chaos. Unlike the experiment whereby I heated water to see the 'continents' rotate and glide around the tub of hot water, it was the reverse here: things are cooling off and the continents are not moving with the speed they moved in the past.
And that alone could explain some of the other extinctions we see in the geological record: if a continent rotates too much, the unwary animals would be delivered into a totally different climate! And if things moved faster than today, this could happen with relative suddenness! One day, warm and wet and just a few million years later, an ice sheet!
We can only guess. The general rule is, things get less dynamic over time due to loss of energy. The earth is remarkably active even though it is billions of years old. This alone should give us pause to amaze at such a wonder.