Look at your fingernails and watch them grow. That will give you an idea of how fast the plates move relative to one another—about a fraction of an inch to a few inches per year!
For example, moving at about 2 inches 5 centimeters per year, in our lifetime the Pacific Plate moves 10 to 15 feet 3 - 5 meters past the North American Plate along the San Andreas Fault, a transform plate boundary in California. Plate Tectonics and Our National Parks. Divergent Plate Boundaries. Convergent Plate Boundaries. Transform Plate Boundaries. Oceanic Hotspots. Continental Hotspots.
Text and Illustrations by Robert J. Most divergent plate boundaries are underwater and form submarine mountain ranges called oceanic spreading ridges. While the process of forming these mountain ranges is volcanic, volcanoes and earthquakes along oceanic spreading ridges are not as violent as they are at convergent plate boundaries. The third type of plate boundary occurs where tectonic plates slide horizontally past each other. This is known as a transform plate boundary. As the plates rub against each other, huge stresses can cause portions of the rock to break, resulting in earthquakes.
Places where these breaks occur are called faults. A well-known example of a transform plate boundary is the San Andreas Fault in California. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher.
They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.
If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media. Text on this page is printable and can be used according to our Terms of Service. Any interactives on this page can only be played while you are visiting our website.
You cannot download interactives. In , after decades of tediously collecting and mapping ocean sonar data, scientists began to see a fairly accurate picture of the seafloor emerge. The Tharp-Heezen map illustrated the geological features that characterize the seafloor and became a crucial factor in the acceptance of the theories of plate tectonics and continental drift.
Today, these theories serve as the foundation upon which we understand the geologic processes that shape the Earth. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Image San Andreas Fault Tectonic plate boundaries, like the San Andreas Fault pictured here, can be the sites of mountain-building events, volcanoes, or valley or rift creation.
Photograph by Georg Gerster. Twitter Facebook Pinterest Google Classroom. Encyclopedic Entry Vocabulary. Also called the geosphere.
Media Credits The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
0コメント