This image shows the topography, or shape, of the Earth's surface, on land and below the oceans. Mountain ranges, subduction trenches, tectonic plates, and mid-ocean ridges are all visible in the image.
Click on image for full size
Image from: U.S. Geological Survey
The Earth's surface is composed of rigid plates that move relative to each other. The plates have three main motions, and each one has different results.
1) When two plates collide, one may be forced under the other causing ocean trenches, volcanic islands, and mountain ranges.
2) When two plates move away from each other, rifts occur. In the ocean, this process is called sea floor spreading, and on land rift valleys are formed.
3) When two plates slide past each other, there are faults.
Features such as volcanoes and earthquakes exist mainly along the plate boundaries.
Most moons and some planets have many impact craters, however these are rare features on Earth.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, as well as books
on science education!
You might also be interested in:
How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more
Volcanoes erupt when magma from deep below reaches the earth's surface. Once the magma reaches the surface, it is called lava and flows out onto the surface. Some really explosive volcanoes spew out lava...more
A lake is a body of water completely surrounded by land. Lakes can either by salty or fresh water. Most lakes are in places where glaciers used to exist. When a glacier moves forward, it carves away a...more
Earth has a diameter of about 12,756 km (7,972 mi). The Earth's interior consists of rock and metal. It is made up of four main layers: 1) the inner core: a solid metal core made up of nickel and iron...more
The Earth's surface is composed of rigid plates that move relative to each other. The plates have three main motions, and each one has different results. 1) When two plates collide, one may be forced...more
Here's a safe and easy way to make lightning. You will need a cotton or wool blanket. This experiment works best on a dry, cool night. Turn out all the lights and let your eyes adjust to the darkness....more
It takes 3 seconds for sound to travel 1 kilometer (5 seconds to travel 1 mile). The next time a thunderstorm comes your way, look out your bedroom window and watch for lightning. When you see a lightning...more
Why do the 53rd Weather Reconnaissance Squadron and the Hurricane Research Division use different airplanes? Actually, they only use two main types. The top two airplanes in the graphic, the WC-130H Hercules...more