Old Man of Hoy
A big rock stands in the sea. It looks like a man. The waves hit the red rock. This makes the rock change. It is very tall. People like to climb it. Do you want to climb it?
Early Reader · Change the reading level on the articleEarth Science articles — Page 22
Explore rocks, volcanoes, weather, oceans and the processes that shape Earth. Choose an article below; its reading controls let you move between the available levels.
1,427 public articles · Page 22 of 30
Oligocene
The Earth was changing a long time ago. It got much colder. Big ice grew on the land. Grass grew in many places. The world looked new. Can you imagine the cold? Do you like the grass?
Early Reader · Change the reading level on the articleOlivine
Olivine is a green rock. It is deep inside the Earth. This rock is very common. Some people use it for pretty gems. It can even be found on the Moon! Do you like green stones?
Early Reader · Change the reading level on the articleOlympic Mountains
The Olympic Mountains are big. They are in a place called Washington. Many trees grow there. It is a very wet place. The mountains have lots of rain. Do you like the rain?
Early Reader · Change the reading level on the articleOnyx
Onyx is a pretty stone. It has stripes of color. Some stripes are white and some are black. People use it for jewelry. It can look like a fingernail. Do you like shiny stones?
Early Reader · Change the reading level on the articleOolite
Tiny round grains make a rock. They grow in warm water. Water washes them around and around. This builds many small layers. They look like tiny sugar grains. Do you like round stones?
Early Reader · Change the reading level on the articleOpal
Opal is a pretty stone. It can show many colors. Some stones look like they have rainbows inside. These colors are very bright. They help make beautiful jewelry. Do you like bright colors?
Early Reader · Change the reading level on the articleOptymistychna Cave
This is a very long cave. It is in a far land. The cave is like a big maze. You can see pretty rocks inside. Some rocks have many colors. It is a wonder to see. Do you like to explore?
Early Reader · Change the reading level on the articleOrdovician
A long time ago, the world was different. Many animals lived in the sea. Some tiny plants grew on land. The oceans were very big and warm. It was a busy time for life. Do you like looking at old fossils?
Early Reader · Change the reading level on the articleOrganic geochemistry
People study how living things change the Earth. They look at rocks and water. They find out where oil comes from. This helps us learn about our world. It is very neat! Do you like to look at rocks?
Early Reader · Change the reading level on the articleOrogeny
Big mountains grow from the ground. Huge pieces of land push together. They crumple and move up high. This makes tall peaks. It takes a long time. Do you like to climb mountains?
Early Reader · Change the reading level on the articleOrpiment
Orpiment is a bright yellow rock. It looks like gold. People used it to paint long ago. It can be bad for you if you touch it. We must be careful with it. Do you like the color yellow?
Early Reader · Change the reading level on the articleOxbow lake
A river can make a lake. It starts with a big bend. The water cuts a new path. The old bend stays behind. Now it is a still lake. It looks like a U. Can you find a bend?
Early Reader · Change the reading level on the articleOxide mineral
Some rocks are made of metal and air. They can be hard or soft. These rocks are found in the ground. They help us make new things. It is fun to look at rocks. Can you find a rock today?
Early Reader · Change the reading level on the articleOxygen cycle
The air has things we need. Plants make the air we breathe. They use water and air to do this. We breathe the air to live. It helps us stay well. Do you like to breathe deep?
Early Reader · Change the reading level on the articleOzone layer
The sky has a special shield. It stays high above us. This shield stops bad light from the sun. It helps keep us safe. We need it to live. Can you feel the sun's warmth?
Early Reader · Change the reading level on the articlePacific–Antarctic Ridge
A long ridge sits on the sea floor. It is under the deep ocean. It pulls two big pieces of earth apart. This makes the sea floor grow. It is a very big place. Can you imagine the deep sea?
Early Reader · Change the reading level on the articlePacific plate
A huge piece of Earth is under the sea. It is the biggest piece of all. It helps make the islands in Hawaii. This big piece moves very slowly. It is under the deep blue water. Do you like the ocean?
Early Reader · Change the reading level on the articlePainite
This is a very rare stone. It is a bright red color. It was found in a far land. It is hard to find in nature. It is a special treasure. Do you like red stones?
Early Reader · Change the reading level on the articlePainted Desert (Arizona)
The Painted Desert has many colors. You can see red and purple hills. The hills are made of old rock. It is a very dry place. It looks like a land of colors. Do you like bright colors?
Early Reader · Change the reading level on the articlePaleoarchean
A long time ago, Earth was new. Small living things first began to grow. They lived in the water. Some rocks show us they were there. These rocks are very old. Can you imagine a world that new?
Early Reader · Change the reading level on the articlePaleocene
A long time ago, the Earth changed. Big dinosaurs were gone. Small animals began to grow. The world was warm and green. Forests grew everywhere. Many plants lived in the woods. It was a new time. Can you imagine it?
Early Reader · Change the reading level on the articlePaleocene–Eocene thermal maximum
Long ago, the Earth got very hot. It stayed warm for a long time. The air and the sea changed too. This helped new animals live. It was a big change for our world. Can you imagine a very hot day?
Early Reader · Change the reading level on the articlePaleoclimatology
We study the old weather. Scientists look at rocks and ice. They find clues from long ago. This helps us know our world. It helps us plan for later. Can you find a clue in the ice?
Early Reader · Change the reading level on the articlePaleocontinent
Long ago, the land was different. Big pieces of land moved. They crashed together to make huge land. Then they broke apart. This changed where animals lived. It even changed the weather. Can you imagine a giant land?
Early Reader · Change the reading level on the articlePaleoecology
Some people study old life. They look at old bones and shells. These things tell us about the past. It helps us know our world. We can learn from long ago. What do you want to find?
Early Reader · Change the reading level on the articlePaleomagnetism
Rocks can tell us secrets. They hold a tiny pull like a magnet. This pull shows where the world was long ago. It helps us see how lands move. We can learn so much from old stones! Do you like looking at rocks?
Early Reader · Change the reading level on the articlePaleoproterozoic
Long ago, the Earth was very different. Days were much shorter then. There were many more days in a year. The land began to stay in place. It was a time of big changes. Can you imagine a short day?
Early Reader · Change the reading level on the articlePaleosol
This is very old soil. It was made a long time ago. It is now buried deep under rocks. This old dirt helps us learn about the past. It is a cool find! Can you find old dirt in your yard?
Early Reader · Change the reading level on the articlePaleotempestology
Scientists look for clues from old storms. They find sand left by big waves. They look at rings in trees too. These clues show us how storms work. This helps us stay safe today. Do you like learning about storms?
Early Reader · Change the reading level on the articlePaleo-Tethys Ocean
A long time ago, there was a big sea. It was very warm. It sat where Asia is now. The sea slowly went away. Now, land is in its place. Can you imagine a world of water?
Early Reader · Change the reading level on the articlePaleothermometer
We can learn about old weather. We look at old shells and ice. These things show if it was hot. They show if it was cold. This helps us know the past. It is like a time machine. Do you like old stories?
Early Reader · Change the reading level on the articlePannotia
A long time ago, all the land was one big piece. This land was near the South Pole. It was called Pannotia. Soon, the land broke apart. New oceans grew in the gaps. This made space for new life. Do you like to look…
Early Reader · Change the reading level on the articlePantanal
The Pantanal is a big, wet place. Much of it is under water. It has many plants and animals. Many fish and birds live there. It is a wild place to see. Do you like wet places?
Early Reader · Change the reading level on the articlePanthalassa
Long ago, there was a huge ocean. It was much bigger than our ocean today. It went all around the world. This ocean sat next to one big land. Can you imagine a world with so much water? It was a very big place!
Early Reader · Change the reading level on the articleParasequence
Rocks can form in layers. These layers grow in the sea. They make a set of beds. The beds stay together for a long time. This helps us learn about the past. Do you like looking at rocks?
Early Reader · Change the reading level on the articleParícutin
A big mountain grew in a cornfield. It was a volcano. It came out of the ground. It was very fast. It changed the land. Now people visit it. Do you want to see it?
Early Reader · Change the reading level on the articlePartial melting
Some rocks melt inside the Earth. Not all of the rock turns to liquid. Only some parts melt. This helps make new land. It can even make gold and gems. Do you like looking at volcanoes?
Early Reader · Change the reading level on the articlePassive margin
The land meets the sea. This place is very calm. It is not a place where plates crash. It is where land turns into ocean. Big rivers flow into the water here. It is a special part of our world. Do you like the beach?
Early Reader · Change the reading level on the articlePast sea level
The sea level changes. It goes up and down. Big ice melts into the sea. This makes the water rise. It can cover the land. This helps us learn about Earth. Do you like the beach?
Early Reader · Change the reading level on the articlePaweł Strzelecki
Paul was a great explorer. He traveled to many lands. He found a very high mountain. He named it Mount Kosciuszko. He also helped many hungry people. He was a kind man. Do you like to explore too?
Early Reader · Change the reading level on the articlePeatland
Peatlands are wet lands. They are made of old plants. These plants stay under water. This helps the ground stay cool. They help our whole world. Do you like wet places?
Early Reader · Change the reading level on the articlePebble
A pebble is a small rock. You can find them on beaches. They can be smooth or rough. Some are red or green. We use them to make paths. Do you like to find rocks?
Early Reader · Change the reading level on the articlePedology
People study the ground. They look at how soil forms. It can have many layers. This helps us grow food. It is a big job. Do you like to dig in the dirt?
Early Reader · Change the reading level on the articlePelagic sediment
Tiny bits fall to the sea floor. They come from small sea life. Some bits are dust from the air. These bits make a soft layer. It stays far from the land. Can you imagine the deep sea?
Early Reader · Change the reading level on the articlePelagic zone
The big, open ocean is a home. Many animals swim in the deep water. Some fish live near the sun. Others live where it is dark. It is a very big place. Can you swim in the sea?
Early Reader · Change the reading level on the articlePentlandite
This is a shiny rock. It looks like yellow metal. It has nickel inside. We use nickel for many things. It is found deep in the ground. Do you like shiny rocks?
Early Reader · Change the reading level on the articlePercé Rock
This is a giant rock. It sits in the sea. It has a big hole in it. It looks like a ship. Many birds live here. You can see it from the town. Do you want to see it?
Early Reader · Change the reading level on the article