I'm Steve Ember.
And I'm Faith Lapidus with EXPLORATIONS in VOA Special English. Scientists are using the most modern space satellites to solve one of the great mysteries of the ancient world.
|The ruins of Tikal, one of the great Mayan cities. (All Pictures - NASA)|
Our report today begins more than one thousand years ago. Travel with us back in time to learn about the Mayan civilization. Our trip begins in the year eight hundred twenty-five. We are in an area near the border between modern Mexico and Guatemala.
We are in the Mayan city of Tikal. The city has huge buildings made of stone. The morning sun makes the smooth, white stone shine brightly. One of the huge buildings is used for religious ceremonies. It is the temple to the Rain God Chac (chalk). The Rain God demands human blood or he will withhold the rain needed to grow crops. The Mayans kill captured enemies at the top of Chac's temple to please this fierce god.
Mayan scientists use another huge building to study the stars. They use this building and similar ones in other cities to make the Mayan calendar. This calendar correctly shows the seasons and the number of days in the year. Farmers use this calendar to plant crops during the best season for growing. Religious leaders use the calendar to help decide when to hold religious ceremonies.
Thousands of people are in Tikal. Many farmers have come to the city to sell their crops. Many workers make pots or clothing. Others make buildings of stone.
Religious leaders are walking toward a temple. A member of the Mayan royal family is being carried in a large chair. He is followed by large groups of fierce Mayan soldiers. They wear bird feathers and animal skins. They carry dangerous weapons.
The city of Tikal is large. Its center is surrounded by many thousands of homes. The city stretches for several kilometers in many directions. The Mayan people who built Tikal had a very successful civilization.
The people do not know that their civilization will disappear very soon. The people will be gone. The soldiers with their fierce weapons will be gone. The royal family will be gone.
Nothing will remain but the huge stone buildings. In time, thick jungle will cover them, and they will become homes for birds and monkeys. The huge city will be empty.
Many years before European explorers arrived in the western hemisphere, the Maya lived in the area that is now southern Mexico, Guatemala and Belize. Explorers have discovered many of the great cities the Maya left behind. Tikal is one of the largest and most beautiful. But there are many others.
Within these cities, scientists found evidence of a complex written language, advanced mathematics, astronomy and beautiful works of art. But they could never find good evidence about what happened to the Mayan civilization.
What forced these people to leave their homes and their beautiful cities? Could it have been wars? A lack of food? Disease? Recently, part of the answer to this question has come from satellites in orbit around the Earth.
NASA scientists Tom Sever (SEE-ver) and Dan Irwin are experts in the history of the Maya. Mister Sever and Mister Irwin have been working to understand the history of the Maya and their natural environment. They believe that history may hold important lessons for people living in the same areas today.
Mister Sever, Mister Irwin and other scientists hope to help governments and people in the areas continue to live there. The scientists hope that by learning from the Maya, people today will not make the mistakes that caused the Mayan civilization to fail.
Mister Sever has found that by the year nine hundred fifty the huge Mayan population was gone. He believes as many as ninety to ninety-five percent of the Maya population died. The archeologist is using NASA satellites and weather information to study the soil in the area and the ancient Mayan cities for evidence.
He is trying to solve the mystery by studying pollen -- extremely small particles produced by seed plants. He says soil from deep in the earth shows no evidence of any pollen from trees during the time just before the Mayan civilization ended. He says this is one piece of evidence to show why the Maya failed.
He says soil experts found only pollen from weeds and other small plants. Mister Sever says the Maya had always cut down huge amounts of forest. They used the wood for building. They burned it to cook food. They also burned large amounts of wood in extremely hot fires to work with a kind of stone. They used the stone to make floors. In time, the trees disappeared.
|Destruction of forests can be seen from Space.|
The loss of many trees led to loss of soil. Fertile topsoil washed into areas that had once been lakes. Evidence shows that the loss of trees may also have caused an increase in the area's temperature. The increase in heat caused water to disappear. Warmer temperatures also dried out the land. Rising temperatures also may have caused changes in rainfall. These actions all caused a decrease in the crops the Maya could harvest. A loss of food may have led to wars among the Mayan groups.
The ancient city of Tikal is near an area of wetlands. About forty percent of the land used by the Maya were wetlands. Mayan cities were built on or very near these wetlands.
Rain soaks the soil in these wetlands during the rainy season now, much as it did during the Mayan period. This land was extremely important to their environment and survival. The Maya learned to save huge amounts of water to be used during the growing season. Modern satellite photographs shows evidence that the Maya built a series of small waterways called canals. Mister Sever believes they may have done so to control, save and reuse rainwater so they could grow crops during the dry season.
Archeologist Tom Sever says experts used to argue about what caused the Maya to fail. Was it wars, lack of food, disease or political problems? He says scientists now think that all of these things led to failure. But these problems were all the result of a severe lack of water. A natural period of less rain and the cutting of trees reduced their water supply.
Trees began to grow again after the failure of the Mayan civilization. The trees and the jungle covered their huge ancient cities.
Tom Sever studies the ancient Maya. What he has learned has caused great concern about what could happen to the population now living in the same area. This area includes southern Mexico, northern Guatemala and Belize. Farming in these areas is done by a method called slash and burn. Farmers cut down trees or burn them and then plant crops.
The soil is very rich for the first year of planting. But the soil becomes less rich during the second year then becomes poor the next year. Farmers then move deeper into the forest and again cut down or burn the trees to make room for planting new crops. Mister Sever says modern equipment has made it much easier to cut down trees more quickly.
|Severe deforestation on the Mexican side of the border with Guatemala.|
Mister Sever has used satellites to show how slash and burn farming is affecting the Earth. For example, satellite images show part of the border between Guatemala and Mexico. Most political borders are invisible in satellite images. But these photographs show a sharp line between areas of rain forest and farmed areas. The rainforest still exists in Guatemala. But it stops at the Mexican border where the trees have been cut down for farming.
Mister Sever says the governments of the nations involved must take steps to protect the environment or they will suffer problems in the future. He and other scientists are now working with the Guatemalan Ministry of Agriculture to find areas in the ancient Mayan wetlands with good soil.
They also are considering planting test crops in those areas. They hope to bring water to the crops using the same method the Maya did – by building canals. Mister Sever says learning from the Maya is extremely important for the future of this area of the world. He says modern farmers should use those methods that worked well for the Maya and not make the same mistakes that caused the failure of their civilization.
This program was written by Paul Thompson. It was produced by Mario Ritter. I'm Steve Ember.
And I'm Faith Lapidus. Join us again next week for EXPLORATIONS in VOA Special English.