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
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
at the antipode. The angle from true
vertical determines the shape of the "blob with a tail".
CREATING A HOTSPOT
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
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
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
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
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
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
new continent could be uplifted by this shock impact event in a time frame of
"A BLOB WITH A
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
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