My science/technology-related thoughts, sometimes controversial, sometimes can be based on limited knowledge base, logic can be non-perfect as well. I develop my vision in iterations. Don't take this blog as an attempt to convince anybody in anything.
Each post in this blog reflects my level of understanding of Tectonics of the Earth at the time the post was written; so, some posts may not necessarily be correct now.

23 October, 2012

Hawaii Convergent, Part 3. The Moat And Arch Of Hawaii. Now: Active Fracture Tectonics.

Now: Active Fracture Tectonics.
There was a post by me, Sergey D. Sukhotinsky, "Hawaii Convergent, Part 2. Introducing The Concept Of Geofracture (not Plate) Tectonics." < http://divergent-boundaries.blogspot.com/2011/10/hawaii-convergent-part-2-introducing.html > Since then I generalized the concept to include celestial objects. See "Tectonics Of A Celestial Object Driven By Material Differentiation And Migration In Temperature Gradient Under Tidal Deformations."
< http://divergent-boundaries.blogspot.com/2012/07/tectonics-of-celestial-object-driven-by.html > Let's name the concept: "Active Fracture Tectonics".

Basics of Active Fracture Tectonics.
- Driving force. The mechanism to reshape Earth's solid surface (crust) is driven mostly by Earth's tidal deformations by Moon, Sun etc.
- Active Divergent Fracture Zone. The kind of a fracture zone that develops the compressional stress within crust. The next conditions are normally met:
   a) deformations within the fracture zone caused by tidal deformations of Earth's body;
   b) water layer above the fracture zone to provide effective cooling;
   c) access for magma from beneath the fracture zone;
   d) absence of source of external compressional stress that blocks this Divergent Fracture Zone to spread crust.
- Crust Lamination at Divergent Fracture Zone caused by material differentiation and migration In temperature gradient under tidal deformations. A Divergent Fracture Zone develops mechanically stronger fraction on the top of the spread crust due to water ensured temperature gradient. The weaker fraction is getting spread on the bottom of it in molten form.
- Passive Divergent Fracture Zone. Active Divergent Fracture Zone can't be curvy. Thus, some regions of a spherical crust  undergo extensional stress. The resulting Divergent Fracture Zones could develop in Active Divergent Fracture Zone if the listed above conditions are met. Otherwise Passive Divergent Fracture Zone develops under extensional stress. The conditions that prevent a Divergent Fracture Zone to develop active (just to name a few):
- Absence of water layer above it.
- Limited access of water due to heavy sedimentation.
- Pollution of the zone due to sedimentation.
- Limited access of magma from beneath, say, due to the underlying subducted slab.
- Pollution of the magma from beneath, due to a recycled subducted slab.
- Slab Pull. The Mechanically stronger fraction on the top of the spread crust at a Divergent Fracture Zone can be denser than the underlying magma. So, a subducting slab on delamination could get denser than the underlying magma and get sunk down to the depth of corresponding magma density. That process of slab sinking could be considered as the secondary driving mechanism behind Active Fracture Tectonics. The slab sinking adds seismic events to tidal deformations and participates in magma convection.

The Moat Of Hawaii.
The mechanism to pump magma/lava up to the surface is different between Plate Tectonics and Active Fracture Tectonics. But once magma/lava gets pumped up, both concepts explain the moat as crust overload.

The Arch Of Hawaii. Plate Tectonics's Plume/Hotspot approach.
The Arch Of Hawaii is something that Plate Tectonics's Plume/Hotspot approach has a problem to explain (in my opinion). The common sense tells, if a load is placed on ice then, yes, a depression develops, but, no, there will be no arch around the depression. The Hotspot's idea that hot magma upwells around the depression to form arch seems not to work well, as, for instance, the "hotspotless" mount chain - Line Islands Chain built its own arch without help of a hotspot.

The Arch Of Hawaii. Active Fracture Tectonics approach.
Let's recall - a Divergent Fracture Zone develops mechanically stronger fraction on the top of the spread crust, the weaker fraction is getting spread on the bottom of it in molten form. Hawaii chain is a convergent zone. The top layer of the incoming crust is getting consumed down under crust. The less dense fraction of the bottom layer of the incoming crust tends not to flow under the depression, accumulating at some distance from the convergent zone. The volume of the material with the density less than the density of crust gives local rise to crust forming arch. When that less dense material got the chance to break up through the bent crust, - highly fluid lava shows on the ocean flow in violent volcanic events.

Active Fracture Tectonics: Doing Physics and Maths.
Time unit: Tera second (Tc).
As I wrote in "Hawaii Convergent, Part 2. Introducing The Concept Of Geofracture (not Plate) Tectonics." < http://divergent-boundaries.blogspot.com/2011/10/hawaii-convergent-part-2-introducing.html >:
"There is the only time unit - second, To make records shorter, Tera second (Tc) can be used". There is no much sense in maintaining the over-complicated legacy set of time-span names like Cenozoic, Mesozoic etc. In fact, we just can't afford to ignore help from the side of physicists, mathematicians, software and electronic hardware developers, other scientists. Let's speak one language - the language of physics. Let's not build artificial barriers around particular domain of science, - The Earth does not belong to only geologists. See my, Sergey D. Sukhotinsky's post "Code First, Model First, or Behavior First? (Talking On Plate Tectonics, Earth Science)" < http://weblogs.asp.net/sergeys/archive/2011/08/30/code-first-model-first-or-behavior-first-talking-on-plate-tectonics-earth-science.aspx > .
Earth layers in plain English.
Again, as I wrote in "Hawaii Convergent, Part 2..." there is no much sense in maintaining the outdated concept of "asthenosphere/lithosphere". The changes of properties of Earth with depth that are seen with Geophysics instruments could mark the layers' boundaries. The layers defined this way could be called in plain English, such as "brittle", "ductile", "transition" or similar.

Active Fracture Tectonics: Next Order Approximation compared to Plate Tectonics.
Plate Tectonics did do its great job to consolidate scientists in their research on Earth evolution. Alfred Wegener paid the price to be heard and stay forever in our memories as the hero. But, time's passing, we need to keep on moving on. The very concept that the outer solid layer of Earth is loosely coupled to underlying layer, and the parts of the outer solid layer could be loosely coupled to each other still holds quite well.
What's new is that the loosely coupled parts of the outer solid layer are products of fracture zones. The fracture zones create them off underlying magma, move them, break them apart and provide the force to subduct them (in addition to Slab Pull force.)

Credits (in chronological order) .
1. I was born in Ukraine. This wonderful land must be a special place on Earth. Try to search Famous Ukrainians Hollywood.
2. My mother was Russian born in Russian North not far from Ural region. The life had never been easy in the region.
3. My father is Jewish born in Ukraine.
4. I graduated from MIPT(Moscow), then the best educational institution in Physics/Maths domain in the world.
5. My wife and my daughter are very much helpful.
6. In terms of money: NASA, NOAA, NDF, USGS, many other US-based scientific organizations plus GOOGLE spent billions on products I used virtually for free. Without the products it was not possible to advance a single step in the research.

© 2012 Sergey D. Sukhotinsky.
http://sukhotinsky.blogspot.com/
http://weblogs.asp.net/SergeyS
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Message-ID: <BLU172-W41011A63784270A135073EDB790@phx.gbl>
From: Sergey Sukhotinsky <sukhotinsky@live.com>
To: Sergey Sukhotinsky <cognitive.walkthrough@gmail.com>
Subject: Hawaii Convergent, Part 3. The Moat And Arch Of Hawaii. Now: Active Fracture Tectonics.
Date: Tue, 23 Oct 2012 12:59:55 +0300
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