Estimating the
Size of the Meteorite and Energy Applied to the Crust
John Michael Fischer, 2006, 2019 www.newgeology.us
Summary A
44 mile diameter chondritic meteorite travelling at 20 km/sec impacting
at a 30 degree angle above the surface is sufficient to produce
kinetic energy equal to that of all the landmasses that moved, sliding away
from the impact with near zero friction as explained by the Shock
Dynamics geology theory. Even though the surrounding continental
crust was expelled, enough indicators remain to project a crater
size of 1000 km (621 mi) see "Ground
Zero". To form a crater that big, a 78 mile diameter
chondrite is estimated to be needed, and that is likely to approximate
the size and type of the Shock Dynamics meteorite.
Introduction On June 30, 1908, a meteor exploded in the air over
Siberia. More than 300,000 acres of pine forest were leveled
in an instant. The Tunguska event is thought to have been
caused by a 50 to 60 meter diameter object exploding 8 kilometers
above the ground. Whether it was the fragment of an icy comet
or a rocky meteor, the energy of the blast is estimated to have
been between 10 and 20 megatons of TNT; equivalent to a hydrogen
bomb.^{J } Larger and denser
objects reach the Earth's surface and penetrate, often to a depth
equal to their diameter. The densest meteorites, ironnickel
type, weigh 7.8 grams per cubic centimeter^{K}
(g/cm^{3}), compared to upper continental crust density of 2.67^{L}
g/cm^{3}. The typical speed of an impacting meteorite is in the
vicinity of 20,000^{K} meters per
second (m/s), or 44,740 miles per hour. For comparison, the
velocity of artillery shells is generally between 300
and 1000 m/s^{N}.
Psyche
is an iron/nickel asteroid over 200 km (120 mi) in diameter, orbiting
between Mars and Jupiter
If you have reviewed the presentation at the
www.newgeology.us website,
you have seen that the arrangement of continents, mountain
ranges, and trenches is completely explained as the consequence
of a single explosion in the protocontinent north of present day
Madagascar. This is not at all what one would expect given
our current understanding of physics. Blast effects and pressure
waves should dissipate rapidly away from the impact site, and continents
should not budge. Yet the event was on a scale vastly
larger than humans have ever experimented with. As mentioned
in the website, experience with comparatively
smaller events (though still large for humans) such as earthquakes,
complex craters, and longrunout landslides suggests that a
change occurs in the rheological properties of the crust at large
scales of energy and mass. Continents slide smoothly as if
on ice, while pressure and shear waves propagate unattenuated for
thousands of miles. The apparent sudden freezing in place
of these elements at the end of the event indicates a distinct threshold
energy for such effects. As unpalatable as this seems,
the flawless fit of crustal features with the shock dynamics
scenario leaves us with no other choice.
Energy estimates The apparent "superfluid" nature
of largescale crustal physics makes calculating the forces involved
in setting the continents in motion simply a matter of transmitting
the kinetic energy of the meteorite to the crust to set the pieces
in motion. Based on the shock dynamics scenario, the meteorite
struck at an angle (from the ground) of 30 degrees, azimuth 93 degrees. It
had a density of 7.8 g/cm^{3} if
iron/nickel, or 3.35 g/cm^{3} if
chondritic, and a velocity of 20 km/s. The diameter
will
be calculated below. The greatest part of the explosion
struck the smaller, "East block" of continental crust.
All of the East block collided with Asia, and while Australia
and a number of islands rolled off farther to the east, they lost
momentum in the collision. The computer animation shows that
parts of the East block (New Zealand, Philippines, Australia)
interacted with the crustal wave. This indicates that these pieces of
continental crust, and therefore the whole East block before it
shattered, slid at surface wave velocity, about 150 m/s^{M}.
This is considerably slower
than P (pressure) body waves, which pass through the interior of
the Earth at 8000 to 14000 m/s. However, Rayleigh surface
waves, like ocean waves, travel at near shear wave velocities that
are dependent on wavelength and the medium they travel through. Shear
wave velocities in sediments are quite low, such as 20 m/s in high
porosity clay or 50 m/s in sandy sediment.^{O}
An ideal tsunami ocean wave, in waters 7000 m deep, wavelength
282 km, travels at 943 km/hr or 262 m/s. Because the energy
in the shock wave was far above that needed to fluidize the crust,
it passed through the crust as a fluid medium, similar to a tsunami
wave in waters 2000 m deep, wavelength 151 km, and velocity 504
km/h or 140 m/s. Also, body wave energy falls off at a rate
of 1/r^{2}
since it is an expanding sphere, whereas surface wave energy falls
off much more slowly, at a rate of 1/r since it is an expanding
circle. A study of three powerful tsunamis in the Pacific^{Q}
concluded that "shorterperiod waves attenuate much faster
than longerperiod waves". The wavelength resulting from
the giant impact would have been extremely long. Thus the
crustal Rayleigh wave travelled far from the impact
site before the shock energy fell below the fluidizing level, and
the wave froze in place. The potential distance travelled by
all pieces of the
East block are assumed to have been the same as the unimpeded
portion of the crustal wave that ended as the TongaKermadec Trench. Measurement of distance was made
from the east edge of the crater to the trench. Crustal thickness is 35
km, and overall crustal density is 1/3 of upper crust density (2.67
g/cm^{3}) and 2/3 of lower crust density (2.9 g/cm^{3})^{L},
making it 2.82 g/cm^{3}.
East block components^{L}

km^{2}

Australia

7,686,850

Bangladesh

143,998

Bhutan

47,000

Nepal

140,797

Burma

676,577

Thailand

513,113

Laos

236,800

Vietnam

329,556

Kampuchea

181,035

Malaysia

332,632

Indonesia

1,919,270

Philippines

300,000

Papua
New Guinea

462,840

New Zealand

269,057

Sri
Lanka

65,000

Pakistan

828,453

Total:
17,336,953 km^{2 }Potential East
block
travel distance (crater edge to Tonga Trench): 12,900 km
Kinetic energy (KE) of East block: 17,336,953 km^{2}
x 35 km = 6.0679 x 10^{8} km^{3}
= 6.0679 x 10^{23} cm^{3} 6.0679
x 10^{23} cm^{3} x 2.82 g/cm^{3} = 1.7111
x 10^{24} g = 1.7111
x 10^{21} kg Rayleigh
wave moving
through the crust at 150 m/s^{M}, KE = 1/2 mass
x velocity^{2} so .5 x (1.7111
x 10^{21} kg) x (150 m/s)^{2}
= 1.925 x 10^{25}
Joules
KE of West block The West block was much more massive
than the East block. When a large ball is hit with the same
force as a small ball, the large ball moves more slowly. So
the West block would have moved slower, but how much? All
other things being equal, a comparison of distances travelled versus
velocity is a reasonable measure. The East block would have
travelled 12,900 km (measured from the crater to the TongaKermadec
Trench),
with a velocity of 150 m/s. The distances travelled by components
of the West block are shown below. Because of the significant
rotation of South America, the northern and southern halves are
listed separately.
West block
components

(km^{2})^{L}

Distances
travelled (km)

North America
Northern
South
America Southern
South
America Antarctica Greenland Total:

24,360,000
 1,527,470 (Alaska began as part of Asia)
+
2,703,900 (Central America) = 25,536,430 13,314,766 4,513,234 14,000,000 2,175,600 59,540,030

5843
5389 6539 5000 2416

Determining the
velocity of each component
by comparison to East block potential distance/velocity:

12900 km 150
m/s

=

5843 km
68 m/s

and applying the equation KE = 1/2 mass
x velocity^{2} to each
part gives us

Velocity

Mass*

KE

North
America

68
m/s

2.5204
x 10^{21} kg

5.8272
x 10^{24} J

Northern
S. Am.

63 m/s

1.3142
x 10^{21} kg

2.6080
x 10^{24} J

Southern
S. Am.

76 m/s

4.4546
x 10^{20} kg

1.2865
x 10^{24} J

Antarctica

58
m/s

1.3818
x 10^{21} kg

2.3242
x 10^{24} J

Greenland

28
m/s

2.1473
x 10^{20} kg

8.4174
x 10^{22} J

*Mass = km^{2}
x 35 km x 2.82 g/cm^{3} x 10^{12}
The total mass for the West block is 5.877 x
10^{21}, and the KE
is 1.213
x 10^{25 }Joules
Diameter of the
meteorite As
an imperfect elastic collision, the efficiency of the transfer of momentum from meteorite to target
is
generally quoted as 90%^{K},
but
25% is used here (Ef) as a conservative estimate of that part of the overall energy directed laterally.
Meteorite velocity is 20 km/s. Meteorite density is
7.8 g/cm^{3}
iron/nickel or 3.35 g/cm^{3} chondritic. Vol = meteorite volume
in km^{3}. Vertical high velocity
impacts form a shock wave in the target that is equal in all directions.
An impact at 30 degrees from the ground, as postulated for the Shock
Dynamics event, distributes the energy unevenly, with most in the
downrange (forward) direction, and the least to the sides and uprange
(back). The left image is a sideview cross section; on the
right is the view from above, with arrow thickness indicating strength.
From
 E. Pierazzo, H.J. Melosh. 2000.
"Melt production in oblique impacts".
Icarus 145, pp. 252261.

The combined KE required to move the two blocks is (1.925 x
10^{25})
+ (1.213 x 10^{25})
= 3.138 x 10^{25} J.
Using 1/2 m x v^{2},
KE of the meteorite is 1/2 its mass x (20 km/s)^{2}.
The efficiency of the imperfect elastic collision is conservatively
estimated at .25 transfer of KE to the crust. The first calculation
is for a chondritic meteorite, the second for an iron/nickel meteorite:
1)
3.138 x 10^{28} g(m/s) = 1/2
meteorite mass x (20 x
10^{3)2}
m/s x .25 Ef. There are 1 x 10^{15}
cm^{3}
in a km^{3},
so a density of 3.35 g/cm^{3
}gives us 3.138 x 10^{28} g(m/s) = 1/2(Vol km^{3}
x 3.35 x 10^{15}
g/cm^{3}) x
4.0 x 10^{8}
m/s x .25, yielding 1.873 x 10^{5}
= Vol km^{3}.^{}Assuming for simplicity a spherical bolide,
volume of a sphere is
4/3 pi r^{3}, 4/3 pi r^{3
}= Vol km^{3}, so
1.873 x 10^{5} km^{3
}= 4/3 pi r^{3}r^{3 }= 4.472 x
10^{4 }km^{3}^{}r = 35.5 km, so if
it was a chondritic meteorite,
the diameter
was 2r, or 71 km
(44 miles) and
total impact energy is 1.255 x 10^{26}
Joules = 3 x 10^{10} megatons of
TNT.
2)
3.138 x 10^{28} g(m/s) = 1/2
meteorite mass x (20 x
10^{3})^{2
}m/s
x .25 Ef. There are 1 x 10^{15}
cm^{3}
in a km^{3},
so a density of 7.8 g/cm^{3
}gives
us
3.138 x 10^{28} g(m/s) = 1/2(Vol km^{3}
x 7.8 x 10^{15}
g/cm^{3}) x
4.0 x 10^{8}
m/s x .25, yielding 8.046 x 10^{4}
= Vol km^{3}.^{}Assuming for simplicity a spherical bolide,
volume of a sphere is
4/3 pi r^{3}, 4/3 pi r^{3
}= Vol
km^{3}, so
8.046 x 10^{4}
km^{3
}=
4/3 pi r^{3}r^{3 }= 1.921
x 10^{4
}km^{3}^{}r = 26.78 km, so if
it was an iron/nickel meteorite,
the diameter
was 2r, or 53.6 km
(33.3 miles) and
total impact energy is 1.255 x 10^{26}
Joules = 3 x 10^{10} megatons of
TNT.
For comparison, estimated
parameters
of the Chicxulub impact are: bolide diameter 10.6 to 80.9 km, mass
1.0 x 10^{15}
to 4.6 x 10^{17}
kg, yielding kinetic energy at 1.3 x 10^{24}
Joules to 5.8 x 10^{25}
Joules^{R},
which is one to two orders of magnitude less.
While these estimates are only approximations,
they do show how a moderately large meteorite with a typical
velocity would have had the necessary kinetic energy to accomplish
the actions described in the Shock Dynamics scenario. Also,
while the mass of the West block is over 3 times larger than the
East block, its components travelled much shorter distances,
in accordance with an oblique impact that directed
its energy (61%) to the east. It flung Australia all the
way to the Pacific and plunged India/Southeast Asia into Asia, raising
the largest mountains in the world. Clearly a central force divided
the protocontinent, not random drift as claimed by Plate Tectonics.
Estimating meteorite
diameter from crater size It is interesting
to see the results from an interactive website sponsored by
Imperial College of London and Purdue University. The Earth
Impact Effects Program, by Robert Marcus, H. Jay Melosh, and Gareth
Collins, allows us to input parameters and view the calculated estimate.
The observed diameter of the
Shock Dynamics crater is about 1000 km (622 miles) see
"Ground Zero".
For a chondritic meteorite with
71 km diameter, 3500 kg/m^{3}
density, 20 km/sec velocity, 30 degree impact angle, and 2750 kg/m^{3}
target density, the final crater is 602 km (374 mi) across and 2.03
km (1.26 mi) deep. To make a 1000 kmwide crater the
chondritic meteorite would need a diameter of 126 km (78 mi).
For an iron/nickel
meteorite with
53.6 km diameter, 7800 kg/m^{3}
density, 20 km/sec velocity, 30 degree impact angle, and 2750 kg/m^{3}
target density, the final crater is 636 km (395 mi) across and 2.07
km (1.28 mi) deep. To make a 1000 kmwide crater the iron/nickel
meteorite
would need a diameter of 90 km (56 mi).
Let's see how the program
deals with the much smaller "Meteor Crater" (Barringer
Meteorite Crater) in Arizona. Plugging in a meteorite with
40 m diameter, 7800 kg/m^{3}
density, 12.8 km/sec velocity, 45 degree impact angle, and 2500 kg/m^{3}
target density, the final calculated crater is 1.11 km (0.689 mi)
across and 236 m (775 feet) deep. The actual crater is 1.2
km (0.739 mi) across and 170 m (560 feet) deep.
Largest
piece of the iron/nickel meteorite that formed Meteor Crater, Arizona
Shiva crater


Researchers think they
have found the largest crater on Earth on the west
coast of India. They believe the socalled
Shiva crater was made next to the Seychelles (as
shown at left) and moved north with India. They
estimate that the meteorite was about 40 km in diameter.
Because of their close proximity, the
Shiva impact and the Deccan Traps (flood basalts)
may be related.

* * *
* * * * * References
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Impact Cratering  A Geologic Process. Oxford University
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^{M }Ralph B. Baldwin,
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^{M }W. G. Van Dorn,
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^{O}
Michael D. Richardson, Enrico Muzi, Luigi Troiano, "Shear wave
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^{Q}
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