Nuclear Weapons: Scars on the Earth

Sean Anthony Pulsifer

Mrs. Karen Yeager

Advanced Composition 12

3 December 1999

Nuclear Weapons: Scars on the Earth

Nuclear weapons have a long-lasting and devastating effect on the world for many years after an initial explosion. Fallout from United States atmospheric testing from 1945 to 1963 killed an estimated 70,000 to 800,000 people worldwide. People who have worked in the early nuclear weapons programs have been exposed to significant amounts of radiation (Schwartz 395).

When a nuclear weapon goes off, there are four basic types of explosions: air bursts, surface blast, subsurface burst, and high altitude burst.

An air burst occurs when a weapon is detonated at a height so the fireball does not reach the surface of the earth (Effects Nuclear Explosions). When the shock wave hits the ground, the first wave will "bounce" off to create a second wave. When the blast is higher off the ground, the initial shock wave will be weaker, but will effect a larger area (5.0 Effects Nuclear Weapons). By varying the altitude of the explosion, one can change the blast effects, thermal effects, and radiation effects. Although initially radiation will be a hazard, but the fallout hazard will be almost zero.

A surface burst occurs when a bomb is detonated on or slightly above the earth. Under these conditions, the fireball will encounter the earth. As opposed to air bursts, fallout can be a hazard (Effects Nuclear Explosions). In a surface blast, the shock wave will travel better through the ground (5.0 Effects Nuclear Weapons).

A subsurface burst occurs when the bomb goes off underneath the land or under the water (Effects Nuclear Explosions).In a subsurface water explosion, water would be what a person would see. In addition, the shock wave a person would see will be carrying up to 5% of the total energy. Waves formed from the blast would be upwards of ten meters high and travel for hundreds of miles. If were to crash into a harbor or estuaries, it would cause massive destruction (Pittock 13). Usually a crater will be the result. A result of a subsurface blast will be very heavy local fallout radiation (Effects Nuclear Explosions). A subsurface bomb will also cut thermal radiation to zero (5.0 Effects Nuclear Weapons).

A high altitude burst occurs when the blast is over 30 kilometers high. The fireball from a high altitude burst will be large and travel much faster. The radiation from the blast could travel for hundreds of miles, therefore contaminating a large area. A blast like this could create an intense electromagnetic pulse (EMP) which will destroy anything electronic (Effects Nuclear Explosions).

The blast wave is formed from very high temperatures and moves away from the center of the ground-zero. While expanding, the peaks pressure decreases, and the propagation goes down from the supersonic speed. Most of the destruction from a nuclear blast is from the blast effects. The range of the blast will determine the explosive yield of the weapon (5.0 Effects Nuclear Weapons).

There are many sources for nuclear radiation such as initial radiation, residual radiation, and fallout.

About 5% of all of the energy from a nuclear explosion are in the form of initial radiation. Intensity from the blast will go down very rapidly with distance from the blast, because of the large area fallout will travel.

Residual radiation comes in three forms: fission products, unfissioned nuclear material, and neutron-induced activity. There are more than 300 fission products. Most of these have very short half-lives. However, some of them have half-lives that can be month or years. Unfissioned nuclear material would be some uranium or plutonium that does not undergo fission and are dispersed from the explosion. Neutron-induced activity happens when nuclei are exposed to a major change of neutron radiation, thus making them radioactive. A small area around ground-zero would be the most likely candidate for neutron-induced activity.

Perhaps one of the most deadly effects of a nuclear blast would be fallout. Fallout comes in three major forms: Worldwide fallout, local fallout, and meteorological effects. Worldwide fallout occurs after a nuclear blast and small particles are drawn up into the atmosphere and will travel by atmospheric winds and settle on the earth. There is a long-term danger of worldwide fallout because of the isotopes strontium-90 and cesium-137, which have a very long half-life. These will enter the body from food that has been contaminated with these two radioactive isotopes. In a surface blast, large amounts of debris will be vaporized by the intense heat of the fireball and be sucked up into the radioactive cloud. By doing this, the material will become radioactive and fall back to the earth as local fallout. When a person stays in a contaminated area, they will be affected by radiation. Meteorological effects will effect fallout, most likely local fallout. Some factors from meteorological effects that could accelerate local fallout would be snow and rain (Effects Nuclear Explosions).

The fireball is the ball of gas created when a nuclear device is detonated. The blast heats the surrounding area to a super-high temperature. As soon as the reaction takes place, the energy is concentrated in the fuels. Thermal or blackbody radiation is emitted by every piece of matter. The first "pieces' of energy to escape the explosion are gamma rays. These gamma rays travel at the speed of light, therefore ionizing the air and making "smog" around ground-zero several meters deep. As the fireball cools, the temperature cools and transporting energy drops.

Injuries from the blast can be very deadly. Thermal injury occurs when the skin goes through an intense heating causing injuries "flash burns." When a person gets a first-degree flash burn, no tissue destruction occurs. Getting a first degree flash burn is just like having mild sunburn. Second degree flash burns will cause damage to the dermal tissue. Third degree flash burns kill tissue all through the skin. If a person has third degree flash burns over 25% of his or her body, he or she will go into shock in minutes. Fourth and fifth degree flash burns are possible. These will destroy tissue, muscle, and connective tissue. In Hiroshima most of the people near ground-zero received forth and fifth degree burns.

Eye injury occurs when the cornea surface goes through a heating process. This can happen when a person glances reflexively to the bright light a nuclear blast makes (5.0 Effects Nuclear