Plate Tectonics
Plate tectonics is the theory of plate movements across Earth boundaries. What we must note is that plates always little movement within these plate boundaries. The Earth is divided into these plate boundaries that continue to grind and move across one another. These effects cause Earthquakes and Volcanoes.
ForcesThe three basic driving forces for this theory composes of three basic other theories that scientists have developed. Mantle dynamics, gravity, and Earth's rotation.
A basic theory we can use for the movement of plates is convection theory which ties into all three. Convection is the transfer of heat through solid or fluid materials, heat rises then cools. Once heat cools it sinks. Plate tectonics move above one another depending on the type of movement (Creates Earthquakes) and results in one plate either submerged over another or grinded upon by another plate of an opposing boundary. |
TypesThere are three basic types of plate tectonics:
1. Transform Boundaries: Occur where two lithospheric plates slide, or perhaps more accurately, grind past each other along transform faults, where plates are neither created nor destroyed. 2. Divergent Boundaries: Occur where two plates slide apart from each other. 3. Convergent Boundaries occur where two plates slide toward each other to form either a subduction zone (one plate moving underneath the other) or a continental collision. Then there is a fourth classification for other types of movements that are unknown, Plate Boundary Zones. |
Earthquakes
When you feel tremors on your feet, you probably experienced an Earthquake. An earthquake is a seismic activity associated with Plate Tectonics. Earthquakes happen everyday and every second but most of them are too small to feel.
You can view current Earthquakes at http://earthquake.usgs.gov/.
You can view current Earthquakes at http://earthquake.usgs.gov/.
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Measuring (Old)Scientists use a model called the Richter Scale. This determines the level of an Earthquake. It is a base-10 logarithmic scale. Every measure is 10 times greater than the measure before. So for example, a 5.0 is 10x greater than a 4.0.
The basic formula is: but you can view more formulas here.
The Richter Scale can also be used to measure damage from an Earthquake. Measuring (New)
Unfortunately the Ritcher Scale is inaccurate and only goes up to 10 units. A new method called the Moment Magnitude Scale is in development. This scale gives a bigger accuracy than the Ritcher Scale. Under development still but it gives a more accurate result than local scales given by the old Ritcher Scale.
The formula is: DamageThe damage from an Earthquake is always 10 times than an Earthquake with a smaller scale (See above). The measure can range from knocked down soap bottles, to faults and destruction of entire buildings. The damage creates economic loss and death tolls. For example, the Great San Francisco Earthquake created $524 million in damage and killed 3,000 people.
You should learn how to survive an Earthquake if one is to ever occur. |
Volcanoes
Volcanoes are created when pockets of magma seep out through plate boundaries, faults, or even Earthquakes. Volcanoes are caused by Plate Tectonics. They are destructive to life but help recycle different chemicals to renew Earth's surface.
TypesThere are three ways to classify a volcano:
1. Extinct: Unlikely to erupt again. 2. Dormant: Either not currently active, or scheduled to erupt some time in the future. 3. Active: A volcano erupting currently or about to erupt in present day. Usually at this time, magma is building up. Then after you classify a volcano's activity status, we go into types of volcanos: 1. Hotspot: Area where a volcano may form. 2. Fissure Vents: Linear surface where lava emerges 3. Shield Volcano: A volcano with road, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent. 4. Lava Domes: Volcano built by slow eruptions of highly viscous lava. 5. Cryptodomes: Volcano formed when viscous lava is forced upward causing the surface to bulge. 6. Volcanic Cones (Or Cinder Cones): Volcano from eruptions of mostly small pieces of scoria and pyroclastics that build up around the vent. 7. Super Volcanoes: Volcano that has a large caldera and can produce devastation on an enormous, sometimes continental, scale. 8. Submarine Volcanoes: Volcano in the ocean floor. 9. Subglacial Volcanoes: Volcano underneath icecaps. 10. Mud Volcanoes: Volcano created by geo-excreted liquids and gases, although there are several processes which may cause such activity. DamageVolcanoes create massive damage to the physical environment around them. Magma that seeps out, creating lava creates a destructive flow that causes many structures or habitats to be flattened with new ground. It does give a benefit to recycling the environment but some volcanoes release fumes that create trouble in the atmosphere. The loss of human life during volcanoes is from rocks, smoke fumes creating cancer, or lava itself. Of course these only happen when volcanoes are erupting and are active.
You should learn how to survive an Earthquake if one is to ever occur. |