The key ingredient to Ben's Antipodal Impact Theory is the idea that big cosmic impacts produce profound effects at the antipode of the initial impact site.

Specifically, I propose that a large enough impact (a Grade 4 Impact) will produce a volcanic hotspot at the site of the antipode of that impact. Furthermore, I propose that this hotspot will move in a specific direction, related to the angle of an off-center impact.

Very few impacts are absolutely straight on. Most big impacts are in the range of 30 degrees to 45 degrees to vertical (beyond 45 degrees, there is much more chance of the impact object glancing off as it hits the atmosphere). The off-center nature of an impact will determine how much directional energy is imparted to the hotspot or new continent (see Appendix VII).

An angled impact means that there is a tremendous amount of angular energy transferred from the impact object to the liquid inner Earth. I propose that this angular energy moves around the heavy inner core in all directions until it meets itself at the opposite side of the Earth … at the antipode. The angle from true vertical determines the shape of the "blob with a tail".

At the same time, the seismic energy from the impact will travel around the lithosphere until it reaches a focal point at the antipode. This focused seismic energy will crush the rock in the vicinity of the antipode, making it easy for the angular energy in the inner earth to push up magma through this weakened area, creating a hotspot.

The Earth's crust varies in thickness from 4 miles thick to 40 miles thick. Sometimes, the hotspot will occur in an area of the earth's surface where the crust is quite thick. In this case, even though the surface may be pulverized by the concentration of earthquake waves at the antipode, the surface may be too thick and heavy to allow the hotspot to break through to the surface. In this case, the hotspot follows the path of least resistance and finds relief by following propagated cracks to a weaker, less dense area, as occurred in South America (see Appendix III), Eastern North America (see Appendix IV), the Chesapeake Bay impact's antipode in Australia 35 MYA (see Chapter 6) and the Yellowstone hotspot, which caused the Large Igneous Province in Washington State. See Appendix III for a much more thorough explanation of crack propagation.

This magma with angular energy will move the resulting hotspot in a straight line like a plasma torch cutting through the Earth's crust. Often the hotspot will not appear to be moving in a straight line because it is moving across different latitudes. When this happens, the slower or faster speed of the Earth's surface at these different latitudes will cause the hotspot to appear to move in a curved arc.

However, it is not really moving in an arc. It only appears to do this because the Earth's surface at the latitude into which it is moving has a faster or a slower speed (The Earth's surface at the equator moves 1,000 mph. The Earth's surface near the poles barely moves at all. The Earth's surface at other latitudes moves at a speed in between these numbers, getting slower as it approaches the poles. This is the basis for the Coriolis effect and why our weather moves from west to east in the temperate zones of the northern hemisphere).

Furthermore, if the hotspot were actually staying at exactly the same latitude and only moved longitudinally (a rare event , but one which does occur with South America ... see Appendix III), it would actually move in a straight line.

But the shocking concept for some scientists will be the idea that hotspots move. Often we hear about tectonic plates seeing volcanic activity as they move over hotspots. But, even though tectonic plates may be moving as well, hotspots are moving, too. They have their own directional energy, imparted by the original impact.

What happens when a cosmic impact is even bigger … much bigger (a Grade 5 Impact)?

At some point, a cosmic impact can be so powerful that it does more than just produce a hotspot. It still produces a hotspot, but the extra energy is so powerful that it lifts up a section of the Earth's crust in a dramatic episode of continental uplift.

For continental uplift to occur, the energy from the impact must be so powerful that the formation of the hotspot and the material ejection from the hotspot is insufficient for pressure relief. The energy is so powerful that its lifting power overcomes both the frictional resistance (including its shear strength) of the rock in the crust and the heavy weight of the rock, as well. The energy forces the rock upwards.

All along the Earth's surface near the antipode, the pressure from this energy will be pushing upwards. The lithosphere will shear upwards at the point where the energy is only barely strong enough to move the rock upwards. Then the entire mass will be raised upwards by several thousands of feet, creating the steep walls of the continental shelf.

The key to envisioning this process is to realize that, once the friction of the rocks has been overcome in the shearing process, this huge amount of energy can be devoted solely to raising up the mass of the continent. It is the friction of the shearing process that keeps lesser impacts from becoming more than just hotspots. But once this friction is overcome, a mass of land can be raised up.

This frictional shear resistance results in a counter-intuitive dichotomy … the impact creates either just a hotspot or, at the very least, a small continent. There is no middle ground of creating islands of various sizes, as one might expect.

The reason for this dichotomy of either hotspots or continents is due to the mathematics involved with the amount of energy required to overcome shear friction at any point at the edge of an uplift.

If an impact is powerful enough to cause a hotspot, then, potentially, it could cause an uplift. However, the circumference of a small uplift would have a lot more shear friction to overcome per unit of area uplifted than a large uplift. The problem is the fact that the circumference increases linearly (πd), while the area uplifted increases by the square (1/4πd²). Therefore, more energy is available to challenge shear friction at the edges in bigger impacts than in smaller impacts.

With smaller impacts, the energy can be diverted toward making the hotspot just that much more powerful. In some cases, we might expect the hotspot of a smaller impact to be as powerful and persistent as the hotspot of an impact that also created continental uplift.

The nature of a continental uplift will actually be an "unzipping" action at the edge of the new continent, as a crack propagates along the brittle crust (see Appendix III for more details).

A very large impact would deform the surface of the Earth, pushing the liquid mantle in front of it. The impact would create a shock pulse that would be transmitted through the liquid mantle, around the solid core.

This shock pulse would reignite any existing volcanoes on its way to seeking pressure relief near the antipode of the impact (the volcanoes would see their pressure withdrawn not long after, as the impact surface rebounds).

If, according to some TV documentaries, mega-earthquake waves can travel at speeds in excess of 7,000 miles per hour, it would not be surprising if any continental uplift would see uplift perimeter cracks propagated at this speed or faster, since the impetus for propagation would continue to exert pressure at the point of propagation until the entire perimeter of the continent was established.

Conceivably, a new continent could be uplifted by this shock impact event in a time frame of mere hours.

Whenever an impact is powerful enough to produce continental uplift, the shape of the uplift is usually going to be a "blob with a tail."

At first one might think that the usual shape of continental uplift would be a circular blob. After all, a circle has the best area to circumference ratio of all shapes available. Why wouldn't this shape be the preferred result?

The answer has to do with the nature of the directed energy as it is transmitted through the liquid layers around the heavy metal core.

First, let's remember that the energy will be getting weaker as it moves along. With a huge impact, the energy will still be very strong, even as it reaches the antipode, but it will still be in the process of diminishing.

The energy of the impact rushes through the molten interior towards the antipode from all directions, following the path of least resistance. However, the strength of the energy is not the same from all directions. The energy that is moving in the direction dictated by the angled impact will be the strongest. As this energy moves past the antipode, it will combine with the weaker energy from the other direction to create slightly more uplift force on the weaker side of the antipode than on the stronger side, resulting in a slightly off-center (the antipode being the center) uplifted blob.

However, on the strong side, there will be so much undiminished energy that it will have enough extra force to create an uplifted tail. South America and India are good, clear examples of continents with tails.

It also appears that Siberia (Asia is a mega-continent), crashing into Europe and forming the Ural mountains, and much of the uplifted land in Mongolia and China, has "a blob with a tail" shape. Surprisingly, even Australia had a well-formed tail until that tail was shattered by the uplift of the Indian continent 65 MYA … but more on that later.