Earth's Interior and Surface

Earth, the largest rocky planet, was formed about 4.5 billion years ago. The Earth's interior is divided into four layers which is typical of rocky planets. It is cool on the surface but very hot deep inside the planet. The center, or core, is as hot as 9000 degrees F.

The Earth's surface is unique from the other planets because it is the only one with liquid water. Water helps to make surface features such as rivers, lakes and oceans. The moving plates of the Earth’s surface form other surface features such as mountains, earthquakes and volcanoes.

Bison roaming on mixed grass prairie - a type of <a href="/earth/grassland_eco.html&edu=elem">grassland</a> - at Wind Cave National Park (U.S.). Over one quarter of the Earth's surface is covered by grasslands. Grasslands are found on every continent except <a href="/earth/polar/polar_south.html&edu=elem">Antarctica</a>, and they make up most of Africa and Asia. Grasslands develop where there isn't enough rain for <a href="/earth/forest_eco.html&edu=elem">forests</a> but there is too much rain for <a href="/earth/desert_eco.html&edu=elem">deserts</a>. Grasslands are filled with - you guessed it - grass.<p><small><em> National Park Service</em></small></p>The most majestic of the volcanoes are composite volcanoes, also known as strato-volcanoes. Unlike the <a href="/earth/interior/shield_volcanos.html&edu=elem">shield volcanoes</a> which are flat and broad, composite volcanoes are tall, symmetrically shaped, with steep sides, sometimes rising 10,000 feet high. They are built of alternating layers of <a href="/earth/interior/lava.html&edu=elem">lava</a> flows, volcanic <a href="/earth/interior/ash.html&edu=elem">ash</a>, cinders, blocks, and bombs. This is a photo of Mt. Cotopaxi in Ecuador.<p><small><em>The U.S. Geological Survey</em></small></p>Shortly after 5 am on the 18<sup>th</sup> of April in 1906, most people in San Francisco, CA were awoken by a sudden jolt. The Earth shook violently in a strong <a href="/earth/geology/quake_1.html&edu=elem">earthquake</a>. It lasted for only about a minute, but caused a lot of damage which destroyed much of the city. This photograph was taken just after an earthquake and fires had ravaged the city.<p><small><em> National Archives Still Picture Records Section, Special Media Archives</em></small></p>Hydrothermal vents in the deep ocean are located at tectonic <a href="/earth/interior/seafloor_spreading.html&edu=elem">spreading ridges</a>. While most of the water in the deep ocean is close to freezing, the water at hydrothermal vents is very hot and laden with chemicals. In this <a href="/earth/extreme_environments.html&edu=elem">extreme environment</a>, certain species of <a href="/earth/Life/archaea.html&edu=elem">Archaea</a> and <a href="/earth/Life/classification_eubacteria.html&edu=elem">Eubacteria</a> thrive, enabling a unique <a href="/earth/Water/life_deep.html&edu=elem">food chain</a> including fish, shrimp, giant tubeworms, mussels, crabs, and clams.<p><small><em> Courtesy of NASA</em></small></p>An <a href="http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc000905e.php">8.6 magnitude earthquake</a> struck on 11 April 2012 off of Banda Aceh, Sumatra, Indonesia, followed by a strong aftershock. Earthquake motion was primarily horizontal. A tsunami warning was issued for the Indian Ocean, but was cancelled at 12:36 UTC. A tsunami was observed at 1 meter or less. Find out more about <a href="/earth/geology/quake_1.html&edu=elem">earthquake</a> and <a href="/earth/tsunami1.html&edu=elem">tsunami</a> processes. Check out the resources <a href="/teacher_resources/2011_AGU-NESTA_GIFT_Workshop.html&edu=elem">here</a>.<p><small><em>NOAA</em></small></p>Sinkholes are <a href="/teacher_resources/main/frameworks/esl_bi8.html&edu=elem">natural hazards</a> in many places around the world. They are formed when water dissolves underlying <a href="/earth/Water/carbonates.html&edu=elem">limestone</a>, leading to collapse of the surface. Hydrologic conditions such as a lack of rainfall, lowered water levels, or excessive rainfall can all contribute to sinkhole development. On 2/28/2013, a sinkhole suddenly developed under the house outside of Tampa, Florida, leading to the tragic death of its occupant, Jeff Bush.<p><small><em>Image courtesy of Southwest Florida Water Management District</em></small></p>

Explore Earth's Interior and Surface

Interior

The Earth's interior is made of rock and metal. It has four main layers: 1) the inner core: ...Read more

Surface

Underneath the water that fills the oceans, and the dirt and plants that cover the land, the ...Read more

Surface Features

Look at this picture of the surface of the Earth! Can you find these features? the Pacific ...Read more

Earthquakes

The ground underfoot might seem like it's not going anywhere but it is. It moves. If it moves ...Read more

Volcanoes

There are several ways in which a volcano can form, just as there are several different kinds ...Read more

Plate Tectonics

Many forces change the surface of the Earth over time. The largest force that changes our planet's ...Read more

Elements

An element (also called a "chemical element") is a substance made up entirely of atoms having ...Read more

Geology

Geology means, literally, the study of the Earth. Explore this section to understand the structure ...Read more

Biomes and Ecosystems

Biomes are large areas of the world where there are similar plants, animals, and other living ...Read more

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Did you know?

Did you know that mica minerals make some rocks sparkle? They also may have been the place where life first formed at the bottom of an ancient sea!

Do you know why and where earthquakes happen? Check our our expanded content on earthquakes!

 

Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Tsunami
xTsunami : A tsunami is a sea wave of local or distant origin that results from large-scale seafloor displacements associated with large earthquakes, major submarine slides, or exploding volcanic islands.

Click on the word to find out!

Research Highlights

Gulf Oil Spill: Mississippi River Hydrology May Help Reduce Oil Onshore

Scientists are currently tracking the effects of the oil spill on the wetlands of the Louisiana coast. Robert Twilley and Guerry Holm, scientists from Louisiana State University (LSU), want to learn about...Read more


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