Stage Planning

Stage 1: Below-Ground Shelter Stage

We will not know the impact site with any degree of accuracy until the final days or hours before the impact event. There is a 72% probability that the impact will occur in one of the oceans. This will produce a tsunami with several mile high waves that hit the shoreline and travel inland several hundred miles, washing across the surface of the continents. In selecting the locations for comet shelters, we should focus on "safe harbor" inland areas that may provide some degree of protections from the threat of tsunami.

The impact will produce increased earthquake and volcanic activity. This threat should be factored into the selection of the shelter location. I recommend the shelter be located no closer than 100 miles from where the tectonic plates join. I also recommend the shelter be located no closer than 50 miles from any active or inert volcano.

Just as a massive earthquake will produce aftershocks, an impact from a large comet will produce a sizeable increase in earthquake and volcanic activity. Some of this activity will occur in or near the oceans. This will in turn produce "secondary tsunami". Although these will not be of the size of the comet "impact tsunami", they will still be of a magnitude that can cause great destruction along the coastline, even the coastlines that were not affected by the original "impact tsunami". Because they will occur in many areas of the globe, they represent a considerable threat to all coastal areas around the world for several months.

The best safe harbors are the mountains and the high plateaus. The topography ⁴⁷ of the United States is laid out with the Appalachian Mountains along the eastern United States and a very wide belt of mountains and high plateaus (Sierra Nevada, Cascade Range, Columbia Plateau, the Great Basin, the Colorado Plateau, and the Rocky Mountains) along the western United States. These mountain ranges will also provide some buffer protection to the central areas of the United States from the effect of large tsunami. The East Coast, the West Coast and the gulf coastal plains will be very vulnerable. One of the major challenges in countering the comet impact threat is that many of the largest population centers in the United States reside in these vulnerable areas.

Large cities are a very poor place to locate a shelter. They contain high quantities of combustibles that will feed firestorms of great intensity. Burning cities will also produce very high levels of toxic gases. If at all possible depopulate the large cities and relocate into the countryside.

Western deserts and very dry & arid regions will sustain less firestorm effects. But they may make poor choices for shelter locations because these areas are located far from the materials to construct and stock a shelter complex. Water, food and firewood may represent a very significant problem for these regions.

I recommend that the Stage 1 Shelter Complex be built on high ground, above the ten thousand-year flood plain. This is due to two reasons. Many poisonous gases are heavier than air and will pool in low-lying areas. I also expect significant quantities of rainfall producing extensive flooding. Heat generated by the impact, the firestorms, and the volcanic activity will cause great evaporation, which will lead to significant rainfall and flooding.

The size of the shelter complex should be of sufficient size to sustain self-sufficiency in Stage 3, small farming communities; but the size should not be too large producing a population density that is unsustainable. The size of a shelter complex should be restricted to 800 individuals. Once that size is reached and populated, the complex should be considered closed. At this point another shelter complex should be started at another suitable site.

Map out the shelter complex area. Mark the areas of storage with metal rebar inserted into the ground. Remember to bring a tape measure into the personnel shelter. Map the layout of the underground shelters taking careful measurements. After the impact the exact location of each shelter may not be visually obvious.

The below-ground personnel shelters should be stocked with a 30-day supply of food and water. I believe that it might be possible to exit the shelter after 3 days. This gives a little leeway and it also takes care of the transition to construction of the first Phase 2 shelter.

The personnel shelters should be constructed and sealed quickly. This is to prevent the trenches from filling up with water should it rain.

A below-ground shelter should be considered a confined space. Any time spent in the shelter should be kept to a minimum prior to the comet impact. Otherwise, the percentage of oxygen will be reduced. The normal atmosphere is composed of approximately 21% oxygen and 79% nitrogen. An atmosphere containing less than 19.5% oxygen is considered oxygen-deficient. Conserve oxygen, it is in short supply. The oxygen level inside a confined space may be decreased as the result of either consumption or displacement. There are a number of processes, which consume oxygen in a confined space. Oxygen is consumed during combustion of flammable materials. Cigarette/cigar smoking should be strictly forbidden while in the shelter. Open flames, candles, lanterns should also be restricted for the same reason. The use of gasoline power generators must also be restricted. The number of people working in a confined space and the amount of physical activity can also influence oxygen consumption. Within the shelter personnel should rest and avoid unnecessary movement. Oxygen levels can also be reduced as the result of oxygen displacement by other gases.²⁰ Various types of toxic gases will be created by the impact. Many of these are heavier than air and may seek the lowest point, which may contaminate the shelter unless it is well sealed. Firestorms may try to suck air out of the shelter to fuel the combustion process.

Keeping families together should be a high priority in individual assignments to underground shelter units. Pregnant women should be located in the shelter unit containing a doctor or midwife. The physical and psychological stress from the impact may result in a spontaneous event. Under this circumstance, I recommend that shelter contain a home birthing unit. I would also recommend a book titled Husband-Coached Childbirth: The Bradley Method of Natural Childbirth.

It may become necessary to effect shelter repair while underground. Falling debris and earthquake damage will cause havoc in the shelter. Have shovels, extra sandbags, a few 2’x2’ plywood segments and fiberglass insulation handy within each shelter to effect repairs. If a large impactor should penetrate the shelter, shove fiberglass through the hole and nail one of the sheets of plywood to temporarily seal the breach.

Do not use up all the energy in your flashlights. You will need them when you transition out of the Below-Ground Shelters.

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