Finding Treasure on Land

Compared to looking in the ocean, looking for treasure on land can be much more complicated. The problem is that treasure on land is buried in the earth. The earth, unlike water, is not transparent. On the other hand, when people bury treasure, they tend to bury it on land. Therefore, the odds of finding something on land are higher.

Let’s imagine that you hear a story about a buried treasure. For example, you read about a king who buried a fortune in jewels and precious metals near an ancient town. Your first job would be to turn detective and try to find the ancient town.

Technology plays a big role when looking for something like a town. The first tool you might use is aerial photography. By using a photograph taken from a plane, it is often easier to see things like ancient roadbeds and walls. Something like a roadbed can be easy to miss if you are walking near it, but easy to see from the air.

Another useful tool is infrared imagery. If a solid, stone wall gets buried over time, the stone will often retain heat differently from the ground around it. An infrared photo allows you to see tiny differences in temperature. Something like a buried wall will sometimes stick out like a sore thumb on an infrared photo.

Here are some of the other techniques that archaeologists are able to use to peer underground:

• Explosion waves – By setting off an explosion on the ground, waves of energy flow through the earth. These waves echo differently off different materials in the ground. By mapping the echoes, archaeologists can discover underground features.
• Magnetometer testing – This type of testing lets archaeologists find tiny changes in the Earth’s magnetic field. If iron has been buried in the soil, magnetometer testing can sense it. It also works on certain kinds of stone and fired pottery or bricks.
• Resistivity testing – This tests for changes in resistivity in the soil. The instrument sends electricity through the soil and then measures how easy or hard it is for the electricity to flow to another electrode. A computer then maps the data. Archaeologist can see caverns or chambers, buried walls and other features with this method.
• Metal detecting – A metal detector uses radio signals to detect metal underground. A big metal detector might be able to see metal that is 10 feet deep. Handheld detectors usually can see metal that is buried about one foot deep or so.
• Ground penetrating radar – This type of radar can penetrate the ground to depths of 10 to 100 feet depending on the soil. It sends back data that can build an image of the things that lie underground in an area.