Re: Meteor Program

From: Diane Roy (
Date: Wed Aug 02 2000 - 13:35:22 EDT

  • Next message: Diane Roy: "Re: Chixulub impact explosion"

      From: Keith Littleton
      The proposal that "Most of the energy is released upward"
      is simply not true. Energy is converted into blast impact
      waves that be very destructive to anything and anybody
      nearby. Energy is also converted in seismic waves that
      would create massive earthquakes. The ionization of gases
      at the instant of impact and the massive ejection of
      molten material from the vaporization of the meteorite
      and the target rock would produce a brilliant light
      flash in ultraviolet, visible, and infrared. The infrared
      wavelengths would cause a thermal radiation impulse whose
      fire-ignition effects would be subject to the scaling-
      law function (King 1976).

      AR: I was refering to the blast from the impact. Only 5% on the kinetic energy is converted into the vaporizing explosion. The other 95% of the kinetic energy is transmitted directly to the ground, mostly in the direction which the asteroid was moving. Indeed massive earthquakes would occure, but the actual blast has less of an effect on the surrounding area. The ionized gasses and molten material will cause fires, but not to the same extent as the same blast above ground level.

      For example, the thermal pulse from a stoney-iron
      meteorite with a diameter of only 175 meters (574 feet)
      would ignite vegetation in a radius of 47 km. The seismic
      response to even this small of asteroid would be
      equivalent to either the San Francisco or Alaskan Good
      Friday earthquake. Destructive blast waves would have
      extended as far as 96 km from the impact. If this
      meteorite hit shallow water, a tsunami wave 140 to 285
      meters (459 to 935 feet) high would result. (Neathery
      et al. 1997). This is what a small meteorite will do.

      AR: Absolutly. I was talking about the reletive effects of the blast in the air, on the surface, an uncontained underground blast and a contained underground blast. Those are just the kinds of effects that Creationary Catastrophists are counting on.

    >All asteroid impacts creating impact craters are the
    >same as un-contained underground blasts. These
    >asteroids are so big that the air does not cause
    >enough compression. It is only after entering the
    >ground that critical mass is reached. The blast
    >of an un-contained underground blast is even less
    >destructive than a surface blast.

      According to King (1976) and Melosh (1989) the blast
      is not fully contained underground. A large impacting
      meteorite will create immense lateral blasts and
      earthquakes that will make life quite unpleasant
      in the region of an impact.

      AR: That is exactly what I said above. The crater creating impacts are un-contained, underground blasts.

    >The bright flash is fully contained underground,
    >so instant fires cannot happen.

      Ionization of the atmosphere will occur as well the
      ejection of massive amounts of molten material from
      the crater will create thermal effects that will
      cause instant fires. Anybody who doesn't believe me
      can check the discussion on the topic in King (1976)
      and Melosh (1989)

      AR: This is talking about the radiation from ejecta. I was talking about the bright flash of the blast itself. In this case the result of the bright flash is the melt of the surounding matter which is then ejected from the crater zone.

    >The shock wave is directed almost entirely upward.
    >A much diminished shock wave does follow along on
    >the ground. Most of the energy of the blast is
    >absorbed into moving the earth outward and upward.

      This might be true, but with the enormous energy
      released by an impact, even if only a fraction of
      it goes into blast and a thermal pulse, the result
      of each will be devastating.

      AR: I was comparing the direction of air shock waves of similar size blasts whether the blast was in the air or as an uncontained underground blast. I'm not saying that there would be no destruction, but that comparatively the results of the blast will be less.

    >Is this all accounted for in your program?

      There is no reason for Glenn to account for claims
      that a simple reading of King (1976) and Melosh (1989)
      will easily refuted as being incorrect. The existence
      and magnitude of the effects that Diane Roy denies
      out of hand can be verified by looking through the
      articles in Geheris (1994).

      AR: I have read many books on impacts and impact cratering. They are indeed destructive. I was just wanted to know if Glenn was taking into account the effects of blasts under different conditions.

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