[meteorite-list] Boom, Poof, or Sizzle!

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:04 2004
Message-ID: <400DDD59.35BDD65B_at_bhil.com>

     Hi, Dave,

         The gas can't explode unless mixed thoroughly and in the
     proper proportion with oxygen: two O2 for every CH4. Of course, if
     you wreck the piping, the gas could escape and mix with the
     atmosphere and if it were ignited you'd a gas well fire of
     tremendous size, I guess.
         But the energy released by the complete combustion of 100
     billion ft3 of gas is a pop in the bucket compared with the
     kinetic energy released when an impactor arrives unexpectedly. In
     all the hullabaloo, you would never notice the 100 billion ft3 of
     gas exploding. Of course, if you're close enought to notice, your
     noticing days are probably over.
         The key term is the velocity. You could throw a baseball (I
     imagine) about 30 m/sec. But kinetic energy goes up as the square
     of the velocity. A space rock arrives at 30,000 m/sec, 1000 times
     faster, which means 1,000,000 times more energy.
         The average 100 meter stone impactor coming in at 20,000 m/sec
     has enought kinetic energy to:
         a) crush 10,000 times its own mass of rock, or
         b) melt 100 times its own mass of rock, or
         c) vaporize 10 times its own mass of rock, or
         d) accelerate 100 times its own mass to 2,000 m/sec. (In real
     life, it does some of all these things.)
         But let's say you had a nice space based rail gun that could
     accelerate a rock up to a lousy 1% of lightspeed (3,000,000
     m/sec). It would easy to do if the railgun was long enough.
         That object would have 100,000,000 times more energy than the
     "normal" space rock and could cause the same damage even though it
     only weighed 1/100,000,000 of what the "normal" space rock did.
     Or, to put it another way, at that speed, you could make a
     full-size model of the Barringer Crater with a lump of iron that
     weighed one kilo (2.2 pounds).
         The significance of the squaring of the velocity term is so
     great that you could easily have a moving object whose kinetic
     energy per unit weight exceeds the energy per unit weight released
     from the reaction of the core material of a thermonuclear bomb. A
     suficiently fast moving rock would make "the bomb" seem like a
     fire cracker.
         Kind of interesting for a species whose first weapon was
     thrown rock that the ultimate weapon could well be a rock thrown a
     lot faster!


     Sterling
     -----------------------------------------------------------------------

     David Freeman wrote:

          Dear Listees;
          I came across an interesting bit of reading material
          that noted an area
          here in SW Wyoming is used as a natural gas underground
          storage unit.
          The formation has natural gas pumped into it under high
          pressure and
          the rock formation acts as a natural "tank" if you will.
          This tank holds
          over 110 Billion cubic feet of natural gas (picture an
          arasol can 10
          miles big a mile down). We have another field not far
          to the east,
          just as big, and major coal and coal bed methane
          occurrences in between
          and all over the place, many being developed at a fever
          pace.
          Now to the good stuff that prompted the boom, poof and
          fizzle......
          If the surface injection wells, and the piping down to
          the depth of the
          gas reservoirs were blasted by a meteorite like the
          Barringer Crater
          incident, what would be the odds of an explosion of the
          gas being held
          there? I am sure the gas would escape the "tank"
          formation. A shock of
          this nature could unleash the coal bed methane in
          explosive levels as
          well. There are over 8 major (meaning full capacity
          and 30" diameter)
          natural gas transfer lines through this area supplying
          natural gas to
          all of our friends in other states, we have 25% of the
          US proven
          reserves (out side of Alaska that is).
          Sudden impact barbecue possible?
          inquiring mind wants to know.
          Dave Freeman
Received on Tue 20 Jan 2004 09:00:58 PM PST