So according to the good folks here on CV... what tier, or level of attack potency is needed to shake an entire planet? (assume it's earth sized)
An impact of 100 000 000 Megatons can be felt from anywhere on earth by indoors people. 10 teratons can be felt by some on the other side of the planet. If it is felt by everyone on Earth and causes minor damage on every city, around 2 TRILLION megatons. Tens of QUADRILLION Megatons if it throws everyone and every building etc. from the ground and later destroys the entire surface of the planet. So at least large country level.
Depends entire on how much shaking do you expect to happen, do you mean to the were people across the whole world can barely feel it? Or do you mean houses literally falling down on the far side of the world as a result of it? Because there is a staggering difference between the two.
From a post of mine a while back:
Planet Level/Affecting Or "Shaking" The Whole World
So, like I said, I define (and I hope most agree) planet level as affecting/shaking the planet to a point where it is clearly noticeable by people. In all the planet shaking feats I've ever seen the "shaking" is in the form of earthquakes, and for good reason, earthquakes can be and are caused by means of powerful explosions or meteor impacts (take a note of this last one). And at the end of the day, it simply makes intuitive sense calcing the feat though earthquakes, I mean in layman's terms an earthquake is nothing more than the shaking of the earth. It makes even more sense to calc the feat via meteor impacts, it's the next best thing in our disposal other than having actual super-people running around shaking the planet with their blows. So, with the underlying logic out of the way, which I hope everyone agrees on, it is incredible basic stuff after all... Let's get to the calculation.
I'm sure you've heard of the Richter earthquake magnitude scale, but there is also the Mercalli earthquake intensity scale which measures the effect of an earthquake on the Earth's surface, a I on the scale for example wouldn't be felt while at a maximum of XII even specially built buildings collapse and objects are thrown into the air. What fits our definition of shaking the best is level V where the earthquake is "felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop". All this info can be found at the official USGS government website right here. So how much power is needed to shake every corner of the Earth to at least this degree? Well, there is a pretty awesome calculator we can use for that, developed by Imperial College London and Purdue University, it's called Earth Impact Effects Program, and it allows you to plug in variables for:
- Distance from Impact.
- Projectile Diameter.
- Projectile Density.
- Impact Velocity.
- Impact Angle.
- Target Type.
For the distance form the impact we want the other side of the planet, that's 20,037.5 km, but the calculator only accepts up to 20,000 km (not going to change the result in any significant manner anyway) so we'll go with that. For the density of the projectile and it's velocity we'll put the maximum value from the provided list and the maximum velocity for an object hitting the Earth respectively, why do this and not just crank those two values way up to simulate a human sized superhero fist? Well, although theoretically that would make sense and fit more with the type of showings we have in comics the real world is a bit more rigid and such high/unusual values mess up the calculator since it's based on experimental data, and there is no "9999999 kg/m^3" meteor or material that has ever hit Earth. From all my experience using the calculator using 8000 kg/m^3 for the density and 72.00 km/s for the velocity, and trying out different sizes for the projectile yields the most accurate and consistent results (but if you're really stuck up about this fact you get the exact same results by simulating
Superman's fist a superhero's, i.e extremely small diameter, 10 cm, and speed, 1 km/s, below mach 3, and just cranking the density to high heaven to compensate...). As for the impact angle we put 90 degrees, a direct impact and lastly for the target type "Sedimentary Rock", which is just plain ol' rock and ground. Now the calculator gives us various effects but what we're interested in is the seismic effects and of course the energy the impactor is packing. Very important side note, don't be confused if under the seismic effects the Richter Scale magnitude doesn't match up with the Mercalli Scale intensity, for example in this calc we'll see the Richter value to be 11.3 (more powerful than any earthquake ever recorded and a definite XII+ on the Mercalli Scale) while the Mercalli Scale value will be V. This happens because the Richter Scale value is the value you'd find on the epicenter of the impact while the Mercalli Scale value is the value at the distance we input (20,000 km), obviously the power and destructiveness of the earthquake decreases the further away you are from the impact.
Okay, so with all of the above thoroughly explained; by trying out different projectile diameters (i.e it's size) we can find the minimum values needed to "shake" the entire Earth. i.e to cause a level V earthquake on the Mercalli scale 20,000 km away. And as we can see the energy comes out at 4.90×10^25 Joules. That is above continent or even multi-continent, by a few times in the latter case. Converting to kilotons of TNT that's 1.171×10^13 (11,710,000,000,000/11,7 trillion) kilotons. Plugging that into the all too famous Nukemap Classic we can find the actual extent of the destruction, as we can see the 20 psi overpressure blast wave has a radius of 5,751.51 km. Why only consider the 20 psi overpressure air blast radius? Because it fits the comic book description of "busting" the best, everything in that area, even heavily built and reinforced concrete buildings are demolished. Here's how such a blast would look on Earth:
It is demonstrably a few times above even multi-continental, no debate about it, anyone else saying differently is just ignorant. I've also debunked the Tsar Bomba thing as well all BPIB's calc.
It surpassed the output of Superman's earth benching feat. and it's shockwaves were felt all the way to the watchtower to the core. country-continental
This is actually confirmed by the same scientist that measured his planet level lifting strength whilst in a weakened state:
And this is what she had previously recorded:
That's a pretty damn impressive feat. Certainly above continental level+.
OT: Depends on the feat.
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