Virtual Earthquake - An Introduction. What's an earthquake? Earthquakes occur because of a sudden release of stored energy. This energy has built up over long periods of time as a result of tectonic forces within the earth. Most earthquakes take place along faults in the upper 25 miles of the earth's surface when one side rapidly moves relative to the other side of the fault. This sudden motion causes shock waves (seismic waves) to radiate from their point of origin called the focus and travel through the earth. It is these seismic waves that can produce ground motion which people call an earthquake.
Each year there are thousands of earthquakes that can be felt by people and over one million that are strong enough to be recorded by instruments. Strong seismic waves can cause great local damage and they can travel large distances. What are earthquake (Seismic) Waves? A seismic wave is simply a means of transferring energy from one spot to another within the earth. What's a Seismogram? How is an Earthquake's Epicenter Located? Ohio Earthquake Information. Oceans Alive! | The Water Planet | The Changing Oceans. The face of the Earth is always changing and throughout geologic history oceans have been created and destroyed. Modern geologic evidence indicates that the ocean bottom is moving at a rate from about one-half to six inches a year through a process called plate tectonics.
Roughly 200 million years ago the Earth's surface was very different from the familiar pattern of land we know today. All of the land masses were grouped together into one vast supercontinent called Pangaea. The rest of the globe was covered by a single great ocean known as Panthalassa. Slowly, over millions of years, the great land mass split apart. The pieces began to move over the Earth's surface driven by slowly churning currents in the molten rocks beneath the Earth's hard outer layers. The gigantic plates on the Earth's crust move like a conveyor belt. By about 35 million years ago the pattern of land and sea was very much like it is today. Seafloor Spreading Animation - Earthguide Online Classroom. Seafloor spreading. Cascades Volcano Observatory Why Study Cascade Volcanoes?
Cascade Range Active volcanoes dominate the skyline of the Pacific Northwest. The familiar snow-clad peaks of the Cascade Range are part of a 1,300 km (800 mi) chain of volcanoes, which extends from northern California to southern British Columbia. The volcanoes are the result of the slow slide of dense oceanic crust as it sinks beneath North America (subduction), which releases water and melts overlying rock. This rich volcanic zone contains the well-known landmark volcanoes and approximately 2,900 other known volcanic features ranging from small cinder cones to substantial shield volcanoes. Cascade volcanoes have erupted in the recent past and will erupt again. The time between eruptions is usually measured in decades or centuries, so eruptions are not a part of our everyday experience. Eruptions in the Cascade Range during the past 4000 years. During the past 4,000 years, periods of eruptive activity at various Cascade volcanoes have lasted for a few to tens of years per century.
SeaFloorSpreading. Interactives. Dynamic Earth. Earth's Structure. Layers of the Earth and Seismic Waves. GCSE Bitesize: Seismic waves activity. Welcome to Understanding Geologic Time. Geologic Time. Initially compiled by Laurie Cantwell, Montana State University This section highlights animations, images, interactive graphics and videos used to teach the concept of geologic time in an introductory geology course. Visualizations cover the specific topics of earth history, relative age dating and life through geologic time. Click here to browse the complete set of Visualization Collections. Earth History ChronoZoom (more info) ChronoZoom is a free, open source interactive timeline tool for learning about all kinds of history, stretching back all 13.7 billion years to the Big Bang. Graphical Representation of Geologic Time (more info) An illustration of the 4.5 billion year old Earth's time scale shown as a spiral with pictorial representations of both marine and terrestrial life.
Observe an animation showing growth of a continent. Continental Drift (more info) Animation and interactive timeline illustrating continental drift from the Precambrian to Cenozoic. Changes of life on Earth. Geological Time Scale WebQuest. Plate Tectonics. Geologic Hazards. Some volcanic eruptions are mild and slow, while others are powerful and dramatic.
An eruption happens when magma, gases, or steam break through vents in the Earth's surface. A mild eruption may simply discharge steam and other gases, or quietly extrude lava. A strong eruption can consist of violent explosions that send great clouds of gas-laden debris into the atmosphere, or may consist of explosions that blast sideways from a collapsed portion of the volcano, as happened in the 1980 eruption of Mount St. Helens. Eruptions can alter the land and water locally through lava flows, lahars, pyroclastic flows, and landslides. A lava flow moves through an intersection. Lava entering the sea poses special risks. A lahar is a mixture of volcanic ash, rock, debris, and water that can travel quickly down the slopes of a volcano. A pyroclastic flow is a rapidly-moving mixture of hot, dry rock fragments, ash, and hot gases which knocks down, buries, or burns everything in its path.
Science In Your State: Ohio. USGS Education. Educational Videos | USGS Education. Earth Making Of A Planet (Complete Film) How the Earth was Made. Birth of the Earth (full episode) (how the Earth was made) Virtual Labs. The links on this page are all VIRTUAL LABS offered by the Glencoe textbook company. These labs give the students the adventure of laboratory experimentation without costly supplies, worrisome environmental and safety issues, or time-consuming clean up. They are from all different areas of science: Biology, Physics, Genetics, Earth Science, Physical Science, and Chemistry. Please feel free to try these at home! Students will be directed to specific labs in class but there are over 100 labs offered here! To return to the home page, please click here: Virtual Labs 1) What strategies are involved in solving a science problem? 2) How does thermal energy affect the state of a substance?
3) How can minerals be defined by their properties? 4) How are rocks classified? 5) What are the advantages of alternative energy sources? 6) How can locations in the United States be identified by their geographic features? 7) How are materials from the Earth broken down? 8) How do glaciers shape the land? Exploring Earth Visualizations. Earth Science Virtual Labs. PhET Lab: Plate Tectonics. Topics Plate Tectonics Crust Lithosphere Mantle Density Buoyancy Earth Science Description Explore how plates move on the surface of the earth. Change temperature, composition, and thickness of plates.
Discover how to create new mountains, volcanoes, or oceans! Sample Learning Goals Describe the differences between oceanic and continental crust, including their respective properties of density, composition, temperature and thickness.Predict how changes in composition and temperature change crust density and buoyancy.Draw a time series for different types of plate boundaries and their motions, indicating the related surface features.Deduce the type of plate boundary given images or descriptions of surface features.Explain which types of plate boundaries create crust, and which destroy crust Version 1.02.
PhET Lab: Radioactive Dating Game. SAVAGE EARTH Online. Please note: SAVAGE EARTH ONLINE looks best when viewed using Netscape 3.0 or above, or Internet Explorer 3.0 or above, on Macintosh, Windows 95 or Windows 3.1. If you have an earlier version, or another browser, all pages may not be presented exactly as designed. To view the animations in SAVAGE EARTH ONLINE, you will need the free Flash plug-in. Premiere: July 19, 1998, at 8 pm (ET) on PBS. (Watch for repeat showings on your local PBS station.) From the legendary fury of Mt. About the Series Program descriptions, TV schedule, videotape ordering information, and clips from the series.
Hell's Crust: Our Everchanging PlanetArticle: The Earth at WorkSidebar: Probing the DepthsSidebar: "Black Smokers"Sidebar: The Ring of Fire The Restless Planet: EarthquakesArticle: Earth -- All Stressed OutSidebar: Learning from EarthquakesSidebar: Quake PredictionSidebar: Build Smart, Not Hard Waves of Destruction: TsunamisArticle: Surf's Up! Animations Menu Main Animations:The Hot ZonesEarthquake! Volcanoes. Ring of Fire. The Ring of Fire is a string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean. The Ring of Fire isnt quite a circular ring. Its shaped more like a 40,000-kilometer (25,000-mile) horseshoe. A string of 452 volcanoes stretches from the southern tip of South America, up along the coast of North America, across the Bering Strait, down through Japan, and into New Zealand. Plate Boundaries The Ring of Fire is the result of plate tectonics. The edges of several tectonic plates meet along the Ring of Fire, resulting in a convergent boundary, a divergent boundary, or a transform boundary.
A convergent plate boundary is formed by tectonic plates crashing into each other. Mount St. A divergent boundary is formed by tectonic plates pulling apart from each other. The East Pacific Rise is a site of major seafloor spreading in the Ring of Fire. A transform boundary is formed by two tectonic plates sliding next to each other. Active Volcanoes. GAMEUP | LANDFORM DETECTIVES. Examine a landscape formed by erosion. Science NetLinks: Shape It Up! Glaciers Virtual Lab.