Preservation of evidence
To preservate an artifact is to extend the life an artifact. The preservation of an artifact
is an extremely important job for an archaeologist or historian, if not the most
important. Without preservation archaeologists and historians cannot use it as
evidence for the past, and every artifact is just a piece of a larger puzzle, which is the
past. Evidence which is not properly conserved will become obsolete, good only for
displays. Historic data would be lost.
When first collecting/excavating artifacts from a site, it must be handled with extreme
caution. For example, when lifting objects from the bottom of the sea, it must be kept
in the same seawater to keep it stabilised. It must then be cleaned, identified, sorted
and catalogued. Comparing it to a database can contribute on how to handle the
artifact properly, as it may need special requirements ( e.g. it may corrode easily, be
reactive to air)
An example of a sealifted artifact is the Riace Bronzes, two large bronze statues of
men, which were found accidentally near the beach, in Riace, Italy. It had to be kept
in the same water it was found in, otherwise if suddenly exposed to air it would have
undergone physical and chemical reactions, which would cause the artifact to
deteriorate.
Depending on what climate artifacts have been buried in, the environment can help to
conserve items. Very hot and dry climates can help to preserve artifacts, because the
heat and absence of moisture help to prevent decay. Archaeological finds in Egypt,
such as the ancient ships buried in pits and the pyramids themselves have survived
thanks to the hot and dry climate of Egypt.
What the artifact is buried in also affects how it is preserved. For example, the
presence of calcium can turn bones into hard stone. An example of an entire city
preserved is the city of Pompeii, which were buried in layers of ash and mud when
Mt. Vesuvius erupted.
When preserving artifacts in a controlled environment, such as a museum, there are
many factors which can affect their quality:
Light:
The best way to preserve an object is to keep it in the dark. Light damage is
accumulated, and cannot be reversed. It can cause textiles to weaken and fade, paints
to change colour or become darker, and paper can become weaker, a change in colour,
or bleached/darkened.
Temperature + Relative Humidity:
An ideal temperature is from 20 – 22 degrees Celsius, and with a humidity level of
around 45% to 55%. Fluctuation and sudden changes in temperature and humidity can
cause damage, as materials are contracting and expanding.
Air pollutants:
Air pollutants, which include dirt, soot, pollens, ozone, nitrogen oxide and other
chemicals can easily help to decay artifacts. A good filtering system can help prevent
damage from this.
Pests:
Pests and small animals can cause quick damage to collections if let loose. Pests can
include rodents, birds, beetles, termites, cockroaches and other animals. They can
literally consume artifacts if they are of the right material.
Destruction of Evidence
There are many causes of decay, deterioration and the destruction of evidence.
The most occurring reason for destruction of evidence is the natural environment.
Natural processes of decay
Damage from floods, earthquakes, volcanic eruptions, tsunamis and hurricanes, and
erosion are some examples of natural processes which can damage historical
evidence. Also, in the long term, the weathering effects of climate can also cause
deterioration, such as heat, cold, rain and wind.
Plants and animals also cause much damage to artifacts and evidence. Plants can
crack, split and destroy architecture. Animal pests such as rodents, beetles, fungi and
other bacteria can cause significant damage, from feeding on materials and droppings
can affect materials.
Examples of sites affected by natural processes are Kom Ombo, and the Cheops and
Sakkarah pyramids. An earthquake occurred in 1992, and in Kom Ombo large blocks
weighing 10 tonnes each had fallen because of the shock. The Cheops and Sakkarah
pyramids each lost blocks, and some fissure damage. Damage also occurred to over
150 other Pharaonic, Coptic and Islamic monuments.
Human causes of destruction
The actions of people themselves have caused much damage to historical evidence.
Warfare and conflict are the primary causes of destruction wreaked on evidence,
meaning much historical data has been lost. People have mindlessly destroyed
artifacts from the past, because of hate and disillusion. Barbarian tribes have
destroyed other cultures and religions because of the love of conflict, or the hate for
others.
Mass tourism in the modern day is also a big culprit for destruction of evidence.
Tourists walk around, photograph and touch archaeological sites. Multiplied by the
1000s that can visit an archaeological site in a single day, such as Abu Simbel,
tourists can cause much damage. It is almost ironic because tourists come to visit
sites, and yet destroy them while trying to appreciate them.
Modern development is another threat to archaeological sites. Construction of
residential and commercial areas, roads and tunnels, freeways, skyscrapers and other
constructions destroy evidence beneath and around them. Traffic and industry also
causes damage to evidence, because of the pollution they produce, which can
seriously damage evidence. A particularly nasty form of pollution is acid rain, which
acts like a corrosive agent. In Athens, the Acropolis and its temples, sculptures and
other structures are being rapidly eaten away by this.
Sources:
Antiquity 1 Textbook
http://wiki.spsu.edu/index.php/Preservation_of_Cultural_Artifacts
http://www.loc.gov/preserv/careothr.html
http://www.thc.state.tx.us/museums/musWord/BasicGuideforPreservHistArtifacts.doc
http://archaeology.about.com/od/curation/Curation_and_Preservation_of_Artifacts.ht
m
http://nautarch.tamu.edu/class/anth605/File1.htm
http://www.drgeorgepc.com/DisastersCulturalSites.html