Nature's Toll - Weathering and Decay

Human Body

http://www.deathonline.net/

The time taken for a body to decompose depends on climatic conditions, like temperature and moisture, as well as the accessibility to insects. In summer, a human body in an exposed location can be reduced to bones alone in just nine days.

Day 1 - State of decay

Although the body shortly after death appears fresh from the outside, the bacteria that before death were feeding on the contents of the intestine begin to digest the intestine itself. They eventually break out of the intestine and start digesting the surrounding internal organs. The body's own digestive enzymes (normally in the intestine) also spread through the body, contributing to its decomposition.

On an even smaller scale, enzymes inside individual cells are released when the cell dies. These enzymes break down the cell and its connections with other cells.

Insect activity

From the moment of death flies are attracted to bodies. Without the normal defences of a living animal, blowflies and house flies are able to lay eggs around wounds and natural body openings (mouth, nose, eyes, anus, genitalia). These eggs hatch and move into the body, often within 24 hours. The life cycle of a fly from egg to maggot to fly takes from two to three weeks. It can take considerably longer at low temperatures.

Day 7 (1 Week) - Stage 3: Putrefaction - 4 to 10 days after death

State of decay

Bacteria break down tissues and cells, releasing fluids into body cavities. They often respire in the absence of oxygen (anaerobically) and produce various gases including hydrogen sulphide, methane, cadaverine and putrescine as by-products. People might find these gases foul smelling, but they are very attractive to a variety of insects.

The build up of gas resulting from the intense activity of the multiplying bacteria, creates pressure within the body. This pressure inflates the body and forces fluids out of cells and blood vessels and into the body cavity.

Insect activity

The young maggots move throughout the body, spreading bacteria, secreting digestive enzymes and tearing tissues with their mouth hooks. They move as a maggot mass benefiting from communal heat and shared digestive secretions.

The rate of decay increases, and the smells and body fluids that begin to eminate from the body attract more blowflies, flesh flies, beetles and mites. The later-arriving flies and beetles are predators, feeding on maggots as well as the decaying flesh. They are joined by parasitoid wasps that lay their eggs inside maggots and later, inside pupae.

Day 14 (1 Fortnight) - Stage 4: Black putrefaction - 10 to 20 days after death

State of decay

The bloated body eventually collapses, leaving a flattened body whose flesh has a creamy consistency. The exposed parts of the body are black in colour and there is a very strong smell of decay.

A large volume of body fluids drain from the body at this stage and seep into the surrounding soil. Other insects and mites feed on this material.

The insects consume the bulk of the flesh and the body temperature increases with their activity. Bacterial decay is still very important, and bacteria will eventually consume the body if insects are excluded.

Insect activity

By this stage, several generations of maggots are present on the body and some have become fully grown. They migrate from the body and bury themselves in the soil where they become pupae. Predatory maggots are much more abundant at this stage, and the pioneer flies cease to be attracted to the corpse. Predatory beetles lay their eggs in the corpse and their larvae then hatch out and feed on the decaying flesh. Parasitoid wasps are much more common, laying their eggs inside maggots and pupae.

Day 30 (1 Month) - Stage 5: Butyric fermentation - 20 to 50 days after death

State of decay

All the remaining flesh is removed over this period and the body dries out. It has a cheesy smell, caused by butyric acid, and this smell attracts a new suite of corpse organisms.

The surface of the body that is in contact with the ground becomes covered with mould as the body ferments.

Insect activity

The reduction in soft food makes the body less palatable to the mouth-hooks of maggots, and more suitable for the chewing mouthparts of beetles. Beetles feed on the skin and ligaments. Many of these beetles are larvae. They hatch from eggs, laid by adults, which fed on the body in earlier stages of decay.

The cheese fly consumes any remaining moist flesh at this stage, even though it is uncommon earlier in decay.

Predators and parasitoids are still present at this stage including numerous wasps and beetle larvae.

1 Year -

1 Decade -

The Process of Dying

It is commonly believed that the hair & nails of a corpse continue to grow for a time following death; this is not exactly accurate. Death is not an event, it is more of a process, with the body actually dying in stagesdifferent areas will cease functioning at different times. It is true that the visible portion of hair & nails are formed by a slow and constant action, and that this is one of the last functions of the body to actually cease. What does occur rather, is that the skin pulls away from those somewhat more dry and rigid structures; this gives the illusion that growth continues. Another example of this effect is that the gums pull away from the teeth as they dry out and rot. This is less noticeable with the recently dead, but a more obviously decaying corpse will show this. Certainly, the teeth do not continue to grow substantially following deathespecially as decay grows more evident, as one may compare how much is visible dental anatomy in a recently deceased individual (showing hair & nail "growth"), and later on that same body as the teeth seem much longer. To assume that the teeth grow in this manner far after death is absurdthis is certainly so when they have not done so in decades while alive. To make this assumption of hair & nails continuing to a great extent post-life is nearly this illogical.

The various stages of decay are affected by temperature, moisture, and other environmental effects. The following general timeline of the process of decay:

* One hour after death the muscles totally relax. All contents of the body are now voided, leaving a foul mess.

* Three hours after death rigor mortis sets in, and the body begins to stiffen.

* After the first day the body has returned to room temperature. At this point, the skin dries and contracts making it appear as though the hair and nails have grown, or are still growing.

* Within the first day or two insects will have discovered the body. Flies will lay eggs on the corpse that will rapidly hatch into maggots (within minutes to hours, depending on the species). Preferred areas for these are those with ready access to the moist flesh, such as the eyelids, lips, and open wounds.

* After about two days, the effects of rigor mortis subside, and the flesh is again pliable. Also at this time, the internal tissues begin to decay. This softens and liquefies the internal flesh; gasses begin to build within the rotting flesh.

* Within a week, the flesh has decayed sufficiently to where the flesh feels "liquid like," and the skin easily falls off if molested.

* Within two weeks, the internal gasses build up further. This causes the stomach to distend, and can force bloody dark liquid from the corpse's orifices.

* Within a month, there are extreme signs of decay. The face is discoloured (purplish green) and the tongue extends. The torso has swollen to double its size. Hair and nails easily fall out. After this point, the body becomes "soupy."

* A body interred in the ground will completely rot away to the bones after about ten years. All of the flesh will have liquefied or turned to gas and been absorbed into the surrounding soil.

An estimation of the time of death may be made by comparing the temperature with the body's rigidity. The surrounding temperature will alter this, but a general room-temperature guideline follows:

* Warm and not stiff: death occurred less than three hours ago

* Warm and stiff: death occurred between three and eight hours ago

* Cold and stiff: death occurred between eight and thirty-six hours ago

* Cold and not stiff: death occurred more than thirty-six hours ago

Reposted from Death: The Pale Horse http://lostsouls.damnserver.com/Death.htm#process

Rust

Time gets to the best of us, and even the hardest steel is no exception.

The rate at which rust forms on any ferrous substance can range from instantly--you can watch it form before your very eyes--to the seemingly-eternal rustlessness of the famous Iron Pillar of Delhi, which has withstood corrosion for 1600 years of Indian weather. The rate at which metal decays and rusts depends on several factors: temperature, moisture, oxygen levels, chemical composition of the metal, and the electrical environment.

Temperature: Hot iron rusts faster than cold. Rusting is a chemical change, and heat speeds up the reaction just as it does for nearly all chemical changes.

Moisture: This one is fairly obvious. What is not so obvious is that humidity in the air can be even worse for the iron's health than being submerged. Water acts as a solvent to degrade the metal structure, mixing the iron with oxygen in either the air or in the water.

Oxygen levels: Without oxygen, there is no rust. Oil or grease, or a good quality paint, can help reduce the rate of rust by blocking water & air from coming into contact with the metal surface.

Chemical composition: Stainless steel is made by adding chromium & nickel. High phosphorous content iron also decays more slowly than high carbon iron. The purer the iron, the faster it can rust, but ironically iron that is very nearly completely pure decays more slowly (the rust reaction tends to catalyse around impurities).

Electrical Environment: How electricity flows through and around the metal can affect the rate of rusting. Other metal in contact with the iron, especially when surrounded by an electrolyte such as seawater, will decay first, leaving the iron unaffected. This is why placing a US penny (or other bronze or zinc coin) on a car battery reduces corrosion of the terminals--the rust forms on the coin first.

Steel, in case you didn't know, is mostly iron. It rusts. The thickness of the metal does not affect the rate of decay at all. All rust forms on the exposed surface. The interior of the iron does not rust until the metal above has decayed down to that level. This means that thick metal will survive corrosion longer than thin, and objects with a large comparative surface area, such as steel wool, will decay very rapidly.

There was a television show on The History Channel, represented online @ www.history.com

http://www.history.com/minisites/life_after_people/

The graphics on the website show some lovely decay.

The Show is okay. View it on demand or via rental or at your library for cheap. (Or do what we sometimes do, buy it, watch it, then donate it to the library for a tax break).

http://store.aetv.com/html/subject/index.jhtml?id=cat2900002

I have some notes I took while watching the program. I will enter that in here.

Buildings of Mankind

Mankinds mastery over nature has always been illusionary.

The Fast Version

A few years (still see some recognizable artifacts)

10-20 years, most buildings will be skeletons

40 years.. most of human impact will be gone.

100 years.. pretty much all gone.

Two to three hundred years, it will be all gone.

After 400 years, only careful examination or exhumation will reveal pieces of things. Remember that many Egpytian buildings and finds only survived because they were buried in the Sand.

The Long Way

Most buildings (and other structures) require maintance of some kind to keep them in proper shape. In addition, they have been designed for the flow and control of heat and air that people provides. Without that, some of their structural integrety begins to fall.

Now conditions will change things. If the world becomes totally arid, things might last longer, while wet they will disintergrate quickly.

First, without the presence of humans, nature will quickly take hold. It is only the presence of humans and human actions that keep nature in plant and animal form from taking over things.

The big thing for decomposition is plants. While mold and fungus are useful in the decompositions of wooden buildings, plants are the main killers of buildings. Various crawling plants will attach to the outside and provide both weight and stress in odd directions. In addition, the plants will shoot into the mortar of a stone building and displace it. Plants/ mold/ spores will be the big killer of stone and brick buildings over time.

Plants growing up along the outside of the buildings. There will be roots and such to undermine foundations or shift walls. Once a wall becomes unbalanced, other forces will cause it to topple.

Without the presence of people, many buildings will burn with the first few years of being left alone. There are many flamable things in a human dwelling that left unattended for years, will possibly ignite. Plus powerlines, plus lightning. They will provide charcol for the next round of plants.

In most conditions, in about 40 years all the wooden buildings will be gone. Some will burn, others will rot and be eated by insects. You see the key to this is paint. The reason why paint is applied to most buildings is not as a decorative element, but as a preservative. (And brick buildings are often sprayed with a clear water sealent). Paint keeps out mositure and other elements, preserving both wood and masonry (stuco). Once the paint flakes, the elements get in. It accelerates the process.

Morter and Bricks have to accept some degree of moisture or water, otherwise they won't hold anything together. If that moisture level increases, they will crumble.

Weather will actually be the culprit to destroy roads and most builings in a five years. The expansion and contraction of a building due to heat, moisture, and wind stress, will do a great deal of damage to a building. If a building is not kept from having elements on the inside (i.e. windows closed/ unbroken, internal heat/ cooling to minimize thermal changes, the roof staying intact, and so on) it begins to decay quickly.. as the insides of a building are not designed to withstand "outside elements". Once some cracks occur, plants will invade.

A car will be left as a puddle of crap for a hundred years or so. Rust will claim some of it once water gets through

The window seals in skyscrapers and high rises will fail if not maintained (or kept temporate) in about 10 years. Once such a building begins to lose windows, it is a cascade issue. Once they begin to break, the wind pressure factor will blow out other windows. Once the elements are inside, they will last maybe 100 years before bolts fail or rust takes out support structures.

If one falls, it will probably take down others. Then fires might start to accelerate the process of decomposition.

Even stone buildings in the classic style are not immune to the effects of weather and plants. Errosion will take place. Plants will begin to take their toll. Many ancient structures do survive until this day, but only because people maintain them. Without maintance, they will become a jumble of stones.

One thing you need to keep in mind is that human kind has put in place any number of systems to keep water levels in check. Without people to maintain those systems, water will eventually flow where it should not belong. Dams, Levies, and Canals, are all there for a reason. Without someone running them or maintaing them, water will be in areas it should not be. Imagine the Hoover Dam failing? Or your local Dam?

Any place with subways has pumps that keep water out of the tunnels (as many of the tunnels are below the natural water table). Without intervention, these subtunnels will begin to fill with water and errode the ground around them. Causing things to fall into their sinkholes.