Estimating the Size of the Meteorite and Energy Applied to the Crust
John Michael Fischer, 2006
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, iron-nickel type, weigh 7.8 grams per cubic centimeterK (g/cc), compared to upper continental crust density of 2.67L g/cc. The typical speed of an impacting meteorite is in the vicinity of 20,000K 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/sN.
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 proto-continent 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 long-runout 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.
The apparent "superfluid" nature of large-scale 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/cc and a velocity of 20 km/s. The diameter will be calculated. 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/sM. 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/r2 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 Pacificq concluded that "shorter-period waves attenuate much faster than longer-period 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 Tonga-Kermadec 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/cc) and 2/3 of lower crust density (2.9 g/cc)L, making it 2.82 g/cc.
Kinetic energy (KE) of East block:
KE of West block
and applying the equation KE = 1/2 mass x velocity2 to each part gives us
The total mass for the West block is 5.877 x 1021, and the KE is 1.213 x 1025 Joules
Diameter of meteorite
The combined KE of the two blocks is 1.925 x
1025 + 1.213 x 1025
= 3.138 x 1025 J
For comparison, parameters
of the Chicxulub impact are:
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.
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