Archaeological Excavation

Sites may be underground, aboveground or underwater. Underwater sites include sunken ships as well as entire towns that have been submerged because of shifts in land or water level. An example is Atlantis, the sunken city. Large sites can be located easily, as they are clearly visible and can be traced from descriptions in ancient stories or historical records. Some small less obvious sites have been discovered accidentally by both non-archaeologists and archaeologists.

The traditional way to find sites in a region is by foot survey whereby archaeologists space themselves out at measured distances and walk in preset directions, looking for evidence along the way. Now, aerial photography is used. This reveals variations in vegetation that indicate presence of archaeological evidences. Simple metal detectors are also used to sense metal artifacts that have been buried as deep as 1.8 metres.

Surveying Sites:

Archaeologists make detailed notes about the location of the site and the kind of evidences in the area. Photographs and maps are also taken and drawn. After making a map, the scientists collect the artifacts from the surface of the site. They divide the surface in small squares and examine one area at a time. The locations where artifacts are found are recorded on the map. Some surface artifacts can give information about when or how a site was used.

Underwater Work:

Aerial photography is used in underwater excavation. Photographs taken over clear water may reveal the outlines of sunken harbours and towns. Sonar scanning helps detect underwater objects by reflection of sound waves. Divers also use metal detectors to search for metal objects and underwater cameras to take snapshots of artifacts. Archaeologists work at underwater sites in submersible decompression chambers. They use balloons to raise large objects to the surface for further study.