Core Sampling
How can a scientist learn about what is inside something?
Imagine that a scientist wants to learn about the inside of a tree. They could cut down the tree.
Then, they could look directly at what is inside. But this would kill the tree! Scientists usually
take great care not to damage what they are studying. A better idea would be to take a small
sample of the tree, instead of cutting the whole tree down.
Imagine that another scientist wants to see what is under the ice at the North Pole. They can’t
just cut the North Pole in half to see what’s there. It is far too big. They have to take a sample of
ice.
When scientists want to see inside something that they want to protect or that is too big to cut
apart, they take a core sample. A core sample gives them a little piece of what is inside
something.
Core samples are taken with hollow, round tubes. The tubes are pushed into the sample. When
they are pulled out, scientists can see into the sample. They can also pull the core samples out of
the tube. Then, they can see all the layers that are inside something.
Core sampling is one way to see what is inside something without cutting the object open. Think
about trying to see what is beneath Earth’s surface. Do you think you could take a core sample?
Scientists can see what is on the surface of Earth. Most of earth is covered with water. The land
is made of soil, clay, sand, and rock. Scientists can dig holes in the ground and see that there is
solid rock just under the surface. Scientists call this layer of rock Earth’s crust.
Digging Deeper
Earth’s outer layer in called the crust. Scientists can take core samples of the crust, but the can
only dig so deep. How far do you think scientists have gone? Engineers dig deep holes, when
they build mines. The deepest mine is the world is a gold mine in South Africa. It is 4 kilometers
deep. Even 4 kilometers down, Earth is still solid rock. This is still part of the crust. The deepest
hole ever drilled was in Russia. This hole was 12 km deep. The drill was still in the crust.
One thing about the hole in Russia surprised scientists. It was very hot. It was much hotter than
they predicted. The temperature was 1800C! The temperature on a hot summer day only reaches
38C. Water boils at 100C. It is hard to imagine how hot 1800C would feel. Scientist can’t drill
much deeper than 12km. Their tools get so hot that they will break. Even rock begins to melt at
high temperatures.
Could scientists take a core sample all the way through Earth? Many scientists wish they could.
Unfortunately, Earth is too big and too hot inside. Our planet is 12,756 km across. A core sample
would have to be that long to o all the way through the other side!