Monday, January 27, 2014

Re: [Geology2] More Antipodal Theory -- Rapid Surface Movement



Dear Ben,  I can't get into this debate other than this exception.  One I just don't think it represents real world physics and is moot for me and two: I am very occupied presently and can't provide detailed answers addressing a play by play of your examples, sorry if I leave out any major points-- but the gist is that "surfaces" (sic)( assuming you mean continental masses) don't move without the plate on which they are affixed to so move. They are rooted/fixed to the slab and don't move independently.   So ANY argument about surface moving by itself is disproved and the theory falls down.  In the past I referred you to the Wilson Cycle Series at James Mason University online but I don't see that this was incorporated in your latest posting.

Yes, the Antarctica plate is moving in a circular motion, rotating generally around its center ( yes I said pinwheel--but not to imply extra ordinary velocity-- 2.5-3cm/year) not because it is at the pole but owing to the offset movement of the plates in contact and where they are pushing/dragging.  I forget which plates there are lateral and which-- if any are in a subducting collision.  The Africa plate has a slight rotation vector for the same reason.  The North America plate has changed directon in the past which is traceable by mapping the curve of the Hawaiian Island and seamount chain. Plate movement isn't always one direction for all time but anything attached to it moves with the plate same direction same speed.  Bottomline circular/ "curvilinear" motion is common but they aren't owing to asteroid impacts.

The New Madrid Fault Zone is well understood and has nothing to do with any impact--it is related to plate stretching/failed rifting and an ancient hotspot which the North America plate moved westward over --both over a very long time period.  BTW The present Mississippi River is a captured stream since the last ice sheets moved the drainage from east to south.  The Ohio river isn't all that old either.

 Sir Newton said: For each action there is an equal and opposite reaction--  including "energy form"changes ( e.g kinetic to heat)  which are always summed up to the same total "energy and mass" on each side of the equation in the end.  Momentum is "mass x velocity" and whatever momentum(work/force) goes IN is the "momentum" reaction coming OUT--Nothing more and nothing less.  Bottomline the farther apart the momentum values are the less movement can happen in ordinary physics.

An asteroid -- even one 8 miles wide and moving at 23,000mph, can only impart a momentum/force vector into the earth and a lot of that kinetic energy goes into vaporizing the impactor and target rock out to the rim of the crater. The uplifted rim is about the limits to any land which can get moved.( hint, hint). The energy release in an impact is virtually  instantaneous and not a slow leveraging that overcomes the inertia of an entire plate to change direction or velocity.  The energy levels massively exceed ALL the target rock's brittleness thresholds and it too is vaporized and/or ejected. (Meaning that it can NOT overcome the inertial of an entire plate for various physical dynamics)  This leaves much less energy available to be imparted into "earthquake wave generation" from the original total energy package ( mass x velocity).   Without doing any math, I can see that the residual momentum of the impactor is millions/trillions of times less than the static mass of the plate which had been punched into. Even when you look at major earthquakes the damage is localized.

1) Where it even possible by totally having a totally non-brittle homogenous generic rock/crust, the forces on a given plate would be so equal in all directions, that the plate would go nowhere. 

2) But being brittle at these energy levels, the region where to impactor struck would crumble before it shoved the entire plate and all directions. 

3) Energy transfer would be subject to the square of the distance and would be rapidly dissipated locally so even less energy would be available to provide a "vector" of even a few millimeters. 

Ergo there is no mechanism within the scope of physics for such a disparate momentum equation to meet the basic physics for your theory to work period.

I pointed you to a single known/suspected example of an antipodal impact induced displacement in the known solar system:  "The Bulge" on the asteroid Vesta. Whether or not you looked up an image it is a good conceptual example of things possible.  That said, the crater excavated .15-.25 of the entire asteroid volume and the antipodal bulge is less than one tenth of that excavated volume of the crater.  Using this as a model of an impactor which could cause an antipodal continental shift would have to be the size of one of the minor planets and the energy release would have vaporized the oceans and killed all life.  So far as we know this hasn't happened after the appearance of oceans and life.  I am not addressing the possibility of antipodal volcanism but I am pretty sure there is no remaining example on earth. 

The Deccan traps were erupting several million years BEFORE Chuixilub(sp?) and the antipode was recently identified in a paper.  You might search for it and look at their methodology.  There were a lot of major impacts in the late Cretaceous which have not had the antipodes calculated.  The Chesapeake Bay impactor 34 million years ago excavated down to 8 miles so it might be a candidate where any antipodal vulcanism evidence wouldn't have drifted too far from original location--Which is probably under Mt Everest or nearby.

We are back again to Occum's( alt Accum's) Razor.  We have an excellent understanding of tectonic plate dynamics and we are zeroing in to full computer modeling of mantle currents which are the apparent drivers of plate movement. It works and accounts for 99% of plate theory.  Why therefore keep proposing a new theory which on the surface can be disproved with some very simple understanding of physics, petrology and historical, structural geology.  I am sure you can see all this in a "fast motion movie" in your mind but it is imaginary and not subject to the entire limitations imposed by multi-disciplinary scientific approach.

Eman


From: Ben Fishler <benfishler@yahoo.com>
To: "geology2@yahoogroups.com" <geology2@yahoogroups.com>
Sent: Sunday, January 26, 2014 12:52 AM
Subject: [Geology2] More Antipodal Theory -- Rapid Surface Movement

 
Now that I have posted revisions to my antipodal theory that change the mechanism for creating volcanism at the antipode of a large impact, I will deal with the questions raised by Eman and Lin about other aspects of the theory that appear to be unworkable.

This email will deal with Eman's notes about geological surface features which move at speeds that are far faster than speeds observed today or imputed in the past.

There are two specific examples of these impossibly rapid movements in my book.

The first example concerns the continent of Western Antarctica, which I describe as "pinwheeling" around the South Pole to its present position.

Eman is right. There is no sensible force that would cause such a radically fast movement. Furthermore, the pinwheeling isn't even necessary. The Western Antarctica continent would be in position to be run into by Eastern Antarctica without any pinwheeling needed. My error.

The situation with regard to the Chicxulub impact and the movement of some of the land on the southwestern flank of Eastern North America is an entirely different situation. In this case, I hypothesize that the Chicxulub impact occurred at latitude 30 degrees north. The Chicxulub crater is currently located at latitude 21 degrees north.

I believe that the Chicxulub impact object came in an angle from the northeast and pushed the land at the flank of the Eastern North American continent to the southwest. The impact may not have moved the crater all the way to 21 degrees north, but I believe that it provided a strong start to that process, along with creating a separation that became the Gulf of Mexico and continued up what is now the Mississippi River, on through New Madrid and several hundred miles beyond.

So, why is this scenario any different than the pinwheeling of Western Antarctica? Because there was a huge force involved and this force was not required to do all that much. It didn't have to move an entire tectonic plate. Rather, it merely had to tear one small side of that plate.

The Mississippi River has covered this continental split with untold billions of tons of silt over the past 65 million years, but the underlying fault is still there and it is still reactive. The Chesapeake Bay impact 35 MYA provided a push to the southwest for the entire Eastern North American continent (at geologically acceptable speeds), which gradually closed the gap and causes the transform fault movement that we see in the New Madrid area today.

The only rapid surface movement that I am hypothesizing involves angled directional force 65 MYA applied to the flank area of Eastern North America, starting at the Chicxulub impact point. This movement would have occurred rather quickly, with much spalling, delamination and liquification of underlying rock. 

So, is this possible? I believe that the initial impact force was so huge that it could do this. Furthermore, there is geological evidence that supports this.

There is a geological similarity between the Large Igneous Province (LIP) area in Georgia and Alabama when compared to the LIP area at the tip of the Yucatan Peninsula.

There are also similarities between areas of Belize and Cuba, which would make sense if this Yucatan movement sheared off part of western Cuba as the Yucatan moved to the southwest.

There is also general geological evidence that movement of rock under pressure will cause the moving surfaces to liquify, thus allowing further movement to be far easier.

Finally, there is modeling evidence that an impact of the size of Chicxulub would cause significant liquification of underlying rock. If we add directional force to this equation, why wouldn't movement to the southwest be possible, especially during the time that the vibrational effects of the impact greatly reduced the holding power of friction?

Thanks for your interest. Again, I am always interested in comments.

I'll tackle Lin's question regarding the supervolcano at Lake Toba next.

Regards,

Ben Fishler






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