Welcome to THIS IS AMERICA IN VOA Special English. I'm Faith Lapidus.
One of the world's great natural wonders is in the state
of New Mexico, in the American Southwest.
Nature has created huge moving hills of pure white sand. These sand dunes cover more than seventy
thousand hectares of desert.
Steve Ember and Mary Tillotson are your guides as we explore White Sands
It is one of the
largest sand dune fields in the United States.
The bright white sand dunes are always changing, always moving, like
waves on the ocean. Driven by strong
winds, the sand moves and covers everything in its path. It is like a huge sea of sand.
dunes have created an extreme environment.
Plants and animals struggle to survive.
A few kinds of plants grow quickly to survive burial by the moving sand
dunes. Several kinds of small animals
have become white in color in order to hide in the sand.
Sands National Monument protects a large part of this dune field. It also protects the plants and animals that
live there. More than five hundred
thousand people visit White Sands National Monument each year. They climb on the dunes and observe the
moving sea of sand.
wonder how all this sand arrived in the area.
To understand that, you would have to travel back in time two hundred
fifty million years. An inland ocean
once covered the area. The minerals
calcium and sulfur were at the bottom of the ocean. Over time, the water slowly disappeared. The calcium and sulfur remained. The minerals formed gypsum rock.
seventy million years ago, the Earth's surface, or crust, pushed upward. The rocks formed two groups of
mountains. Later, the crust pulled
apart. The area between the mountains
broke and fell down. It formed a
half-circle shape of a bowl. This bowl
of rock is known as the Tularosa Basin.
twenty four thousand years ago, it rained a great deal in the area. The rain filled the Tularosa Basin and
formed Lake Otero. The rain and snow
that washed down the mountains into Lake Otero carried gypsum with it.
Lake Otero almost completely dried up.
Gypsum remained. A strong wind
moved into the area. It blew across the
land for thousands of years. Pieces of
gypsum broke off. The wind wore them
away to a size small enough to pick up and carry for short distances. Wherever the wind dropped sand, dunes
dunes at White Sands National Monument are unusual because they are made of
gypsum. Gypsum sand is different from
common sand. Most sand is made of
quartz, a hard silicon crystal. Gypsum
sand is made of softer calcium sulfate.
It dissolves easily in water. So
it is rarely found in the form of sand dunes.
Most gypsum would be carried away by rivers to the sea. But the Tularosa Basin is enclosed. No rivers flow out of it. So water with dissolved gypsum has nowhere to
sand is being made all the time. The
dunes continue to form and move under the influence of water and wind. Water continues to wash down from the
mountains carrying dissolved gypsum into the Tularosa Basin. Wind continues to blow across the Basin
carrying the gypsum.
gypsum sand grains crash into each other. The crash creates tiny lines or
scratches on the surface of the sand.
These scratches change the way light shines off the surface. This makes the sand appear white. The sand dunes look like great masses of
bright white snow. But they are not
cold and wet. It only rains about eighteen
centimeters each year.
There are four kinds of sand dunes at White Sands National
Monument. Some of the dunes are small
and fast-moving. They are called dome
dunes because they are shaped like a half-circle. Few if any plants grow on them.
These dunes move the fastest, up to twelve meters a year.
Other dunes are
called transverse dunes. They form in
long lines across the dune field. They
can grow to be one hundred twenty meters thick and eighteen meters high.
kind of dunes are barchan dunes. They
form in areas with strong winds but a limited supply of sand. These dunes have sand in three parts, like a
body in the center and two arms on the sides.
The sand in the two arms moves faster than the sand in the center.
dunes are the opposite of barchan dunes.
They form when plants hold sand in the outer parts of the dune but the
center of the dune continues to move.
You may wonder how anything can live in this extreme
environment of a white sand desert.
There is not much rain. The heat
in summer is intense. The sand lacks
Yet almost four hundred kinds of animals live in White
Sands National Monument. Many of them
are birds or insects. There are also
twenty-six kinds of reptiles, including rattlesnakes and lizards. And there are more than forty kinds of
mammals. They include rabbits, foxes
Scientists know that plants and animals often change to
be able to live in extreme environments.
For example, they change color to protect themselves from enemies. Many of the animals that live in the sand
dunes have become white. So it is
difficult to see the animals in the sand.
There is another reason why you may not be able to see
the animals. Many of them remain
underground during the day when it is very hot. They come out at night when it is cooler. You may be able to see their footprints.
do grow in the White Sands dune field.
But even plants that grow in most deserts have trouble surviving. A major reason is that the dunes bury any
plants in their way as they move across the desert. Yet, a few plants have developed techniques to avoid being buried
by moving sand.
For example, some plants grow taller and their roots grow
deeper into the sand. The soaptree
yucca plant can make its stem grow longer to keep its leaves above the
sand. The plant grows up to thirty
centimeters a year.
White Sands National Monument is about twenty-four
kilometers southeast of the city of Alamogordo, New Mexico. In the visitor center at the entrance of the
park, you can find out about special activities and guided walks. From the visitor center, you can drive about
thirteen kilometers into the center of the dunes. It is like driving on a lonely white planet. Along the way there is information that
tells about the natural history of the white sands.
also explore the dunes on foot. There
are four marked trails. Signs along the
trail tell about the plants growing in the sand. You can see some unusual and beautiful plants and flowers growing
in the sand dunes. But you may not
remove or destroy any plants or animals at White Sands.
even camp there overnight. But you must
be careful. It is easy to get lost in
the waves of moving sand especially during sandstorms. There is no water to drink. The temperature can rise to thirty-eight
degrees Celsius in summer. There is no
shelter from the sun's rays.
There is another reason to be careful at White Sands
National Monument. The White Sands
Missile Range completely surrounds the park.
It covers one million hectares.
The missile range was first used as a military weapons testing area
after World War Two. It was used to
test rockets that were captured from the German armed forces. The missile range continues to be an
important testing area for experimental weapons and space technology.
tests take place about two times a week.
For safety reasons, both the park and the road from it south to Las
Cruces, New Mexico may be closed for an hour or two while tests are taking
Sands National Monument is part of America's National Parks System. The park system includes more than three
hundred seventy protected areas. White
Sands National Monument is just one of the more unusual examples of America's
natural and cultural treasures.
program was written by Shelley Gollust and read by Steve Ember and Mary
Tillotson. I'm Faith Lapidus. Internet users can find our programs at
voaspecialenglish.com. We hope you join
us again next week for THIS IS AMERICA in VOA Special English.