Horizon
The horizon is a line. It is where the land meets the sky. You can see it far away. It looks like a circle around you. If you go high up, you see more. Can you find the line?
Early Reader · Change the reading level on the articleEarth Science articles — Page 4
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 4 of 30
Hotspot (geology)
Hot spots are very hot spots deep down. They make volcanoes rise up. The ground moves over the heat. This makes a long line of islands. It is like a trail. Do you want to see a volcano?
Early Reader · Change the reading level on the articleHot spring
Hot springs are warm water pools. They come from deep in the ground. The heat from the Earth warms them up. People use them to relax. They can be very hot! Do you like warm water?
Early Reader · Change the reading level on the articleHumidity
Air has tiny bits of water in it. You cannot see this water. It can make fog or rain. When it is wet, we feel hot. It helps us know the weather. Do you like wet air or dry air?
Early Reader · Change the reading level on the articleHydrography
People study the water. They look at big oceans. They look at small rivers. This helps ships stay safe. It helps us know the water. Do you like the water?
Early Reader · Change the reading level on the articleHydrology
People study how water moves. Water falls as rain. It flows in rivers. Some water hides under the ground. This helps us find clean water to drink. It helps us stay safe too. Do you like the rain?
Early Reader · Change the reading level on the articleHydrosphere
Earth has much water. It is in oceans and lakes. Water is also in the air. We need water to live. It helps all things grow. It is a blue planet. Do you like to swim?
Early Reader · Change the reading level on the articleIce
Ice is frozen water. It is very cold. It can be clear or white. Ice floats on top of water. This helps fish live underneath. Ice is fun for sports too. Do you like to play in the snow?
Early Reader · Change the reading level on the articleIce age
Sometimes the Earth gets very cold. Large sheets of ice cover the land. These cold times are called ice ages. They change how we live. The ice can move big rocks. Do you like the snow?
Early Reader · Change the reading level on the articleIceberg
An iceberg is a big piece of ice. It breaks off from a glacier. Most of the ice is under the water. It floats in the sea. It can be many shapes. Do you want to see one?
Early Reader · Change the reading level on the articleIce sheet
An ice sheet is a giant mass of ice. It covers very large lands. It gets thick from falling snow. This ice can move very slowly. It is very cold there. Do you like the snow?
Early Reader · Change the reading level on the articleIce shelf
A big slab of ice floats on the sea. It comes from ice on the land. This ice helps stop other ice from moving too fast. It is very thick and cold. Can you see the white ice?
Early Reader · Change the reading level on the articleIgneous rock
Hot melted rock makes new stone. It can be deep underground. It can also come out of a volcano. This rock is very strong. It helps make our world. Do you want to find some rocks?
Early Reader · Change the reading level on the articleIranian plateau
A large land sits in the sun. It has many big mountains. Some parts are dry like a desert. Many animals live in the trees. You can see bears and foxes there. It is a big, busy place. Do you like to explore?
Early Reader · Change the reading level on the articleJade
Jade is a pretty rock. It can be many colors. It is often green. Some jade is even white or black. People use it for jewelry. It is very special. Do you like green rocks?
Early Reader · Change the reading level on the articleJet stream
Fast winds fly high in the sky. These winds move from west to east. They help planes fly faster. They also change our weather. Do you like to watch the clouds?
Early Reader · Change the reading level on the articleJurassic
Long ago, the world was warm. Big dinosaurs lived on land. Some lived in the blue sea. Many green plants grew everywhere. It was a busy time. Do you like dinosaurs?
Early Reader · Change the reading level on the articleKaolinite
This is a soft white clay. It comes from old rocks. It can be pink or red too. We use it to make many things. It is very useful. Do you like to play in clay?
Early Reader · Change the reading level on the articleKarst
Rain can change the ground. It makes holes in the rock. These holes can become deep caves. Some rivers hide under the earth. This is how a karst land forms. It is very cool to see. Do you want to explore a cave?
Early Reader · Change the reading level on the articleKöppen climate classification
The world has many kinds of weather. Some places are very hot. Some places are very cold. This helps us know what plants grow there. It is a way to group the Earth. Does your home have hot or cold weather?
Early Reader · Change the reading level on the articleKrakatoa
Krakatoa is a big island. It is in the sea. It has a hot mountain. The mountain can blow up. This makes a big splash. A new island grew there. It is called Child of Krakatoa. Do you like volcanoes?
Early Reader · Change the reading level on the articleLagoon
A lagoon is a shallow pool of water. It sits next to the big ocean. A thin strip of land keeps it safe. This water can be salty or fresh. It is a special place to see. Can you find a lagoon near you?
Early Reader · Change the reading level on the articleLake Baikal
Lake Baikal is a very big lake. It is the deepest lake in the world. It has very clear water. Many animals live in the water. A seal lives there too. It is a special place. Do you want to see it?
Early Reader · Change the reading level on the articleLake Vostok
A big lake hides under the ice. It is deep under the cold ground. The water stays liquid under the heavy ice. It is very dark and very cold there. We think tiny life might live in it. Could anything live in the dark?
Early Reader · Change the reading level on the articleLandform
The Earth has many shapes. You can see big hills. You can see deep valleys. Some shapes are made by nature. Some are made by people. These shapes are everywhere. Can you find a hill near you?
Early Reader · Change the reading level on the articleLandslide
Sometimes the ground moves. Dirt or rocks can slide down hills. This can happen when it rains a lot. It can also happen when the ground shakes. This can be scary for people. Have you ever seen a big hill?
Early Reader · Change the reading level on the articleLate Devonian mass extinction
Long ago, life in the sea changed. Many sea animals died out. This happened in the big ocean. It was a hard time for them. It changed how the world looks today. Can you imagine a world like that?
Early Reader · Change the reading level on the articleLate Ordovician mass extinction
Long ago, the world changed. The sea got very cold. Huge ice grew on Earth. Many sea animals died. This was a hard time. But life came back. Can you imagine a world of ice?
Early Reader · Change the reading level on the articleLava
Lava is melted rock. It comes from deep inside the Earth. It can flow like thick ketchup. When it cools, it turns into hard rock. It is very hot! Have you ever seen a volcano?
Early Reader · Change the reading level on the articleLimestone
Limestone is a hard rock. It often comes from the sea. Shells and coral build it up. It can even have old fossils inside. We use it to make roads. Can you find a rock like this?
Early Reader · Change the reading level on the articleLimnology
People study water in many places. They look at lakes and rivers. They see how fish live. They see how plants grow. This helps us care for our world. Do you like to swim in a lake?
Early Reader · Change the reading level on the articleLithosphere
Earth has a hard outer shell. It is made of rock. This shell is broken into big pieces. These pieces move very slowly. They make up the ground we walk on. Can you feel the hard ground?
Early Reader · Change the reading level on the articleLittle Ice Age
The world was very cold. It stayed cold for a long time. Some rivers even turned to ice. People could skate on them. It was a chilly time. Did you ever feel very cold?
Early Reader · Change the reading level on the articleLow-pressure area
Sometimes the air moves in a special way. This can bring clouds and rain. It can also bring wind. The air rises up high. This makes the weather change. Do you like the rain?
Early Reader · Change the reading level on the articleMagma
Hot liquid rock is under the ground. It can have bubbles in it. It can have tiny rocks in it too. This hot rock helps make new rocks. It can even feed a volcano. Can you imagine hot rock?
Early Reader · Change the reading level on the articleMarble
Marble is a pretty rock. It can be white or pink. It has swirls of color. People use it for big buildings. It is also used for statues. Do you like shiny rocks?
Early Reader · Change the reading level on the articleMariana Trench
The ocean has a very deep spot. It is a long, curved place. It is the deepest part of the sea. It is deeper than a high mountain. Small life lives in the dark water. Do you want to go there?
Early Reader · Change the reading level on the articleMarie Tharp
Marie Tharp made maps of the sea. She found mountains under the water. She drew where the ocean floor was deep. This helps us know our big Earth. We can see the world better now. Do you like to look at maps?
Early Reader · Change the reading level on the articleMarsh
A marsh is a very wet place. It is full of tall grass. Many birds and fish live there. It helps keep our water clean. We must help keep them safe. Do you like wet places?
Early Reader · Change the reading level on the articleMauna Loa
Mauna Loa is a huge volcano. It is in Hawaii. This mountain is very big. It can make hot, runny rock. This rock flows like water. It is a very special place. Do you want to see it?
Early Reader · Change the reading level on the articleMesa
A mesa is a flat hill. It looks like a big table. It has very steep sides. It stands high above the ground. It is a cool sight to see. Have you seen a hill like this?
Early Reader · Change the reading level on the articleMesozoic
Long ago, dinosaurs ruled the Earth. They lived in a very hot world. Big plants grew everywhere. Small mammals lived too. This was a time of big changes. Do you like dinosaurs?
Early Reader · Change the reading level on the articleMetamorphic rock
Some rocks change into new rocks. Deep heat and heavy weight change them. This happens under the ground. It makes the rocks look and feel new. We use some for buildings. Do you like rocks?
Early Reader · Change the reading level on the articleMeteorology
People study the air and weather. They look at clouds and wind. This helps us know if it will rain. It helps us stay safe too. We can learn about the sky. Do you like the rain?
Early Reader · Change the reading level on the articleMica
Mica is a shiny rock. It can split into thin sheets. These sheets can be very small. We use it to make things shine. It is in some paints and makeup. Do you like things that glitter?
Early Reader · Change the reading level on the articleMid-Atlantic Ridge
There are mountains under the sea. They are very long. They stay in the middle of the ocean. Some parts even poke out of the water. Iceland is one of those places. It is a big, amazing sight. Can you imagine a…
Early Reader · Change the reading level on the articleMid-ocean ridge
Big mountains hide under the sea. They make new ground. Hot melted rock rises up. It cools to make more floor. This helps our world grow. Can you find them on a map?
Early Reader · Change the reading level on the articleMineralogy
People study rocks and gems. They look at how they shine. They check if they are hard. Some can even scratch others. This helps us learn about Earth. It is very fun. Do you like shiny stones?
Early Reader · Change the reading level on the article