Term
| What are the four main areas of Earth Science? |
|
Definition
-Geology
-Oceanography
-Meteorology
-Astronomy |
|
|
Term
|
Definition
| Geology is the science that examines Earth, it's form and composition, and the changes it has undergone and is undergoing. |
|
|
Term
|
Definition
| Oceanography is the scientific study of the oceans and oceanic phenomena. |
|
|
Term
|
Definition
| Meteorology is the scientific study of the atmosphere and atmospheric phenomena; the study of weather and climate. |
|
|
Term
|
Definition
| Astronomy is the scientific study of the universe; it includes the observation and interpretation of celestial bodies and phenomena. |
|
|
Term
| Why does Earth have layers? |
|
Definition
| Shortly after Earth formed, the decay of radioactive elements, combined with heat released by colliding particles, produced some melting of the interior. This allowed the denser elements, mostly iron and nickel to sink to Earth's center. The lighter, rocky components floated outward, toward the surface. This sinking and floating is believed to still be occuring today, but on a much smaller scale. As a result of this process, Earth's interior is not made of uniform materials. It consists of layers of materials that have different properties. |
|
|
Term
| What are Earth's major spheres? |
|
Definition
-Hydrosphere
-Geosphere
-Atmosphere
-Biosphere |
|
|
Term
|
Definition
| All of the water on Earth makes up the hydrosphere. The water-cycle has a great importance to this planet-- the biosphere would be nonexistent without this sphere. |
|
|
Term
|
Definition
The geosphere is divided into three parts: the core, the mantle, and the crust.
The crust is the rigid outer layer we're all familiar of. It is also called the lithosphere, when combined with the upper-mantle. It is the thinnest and less dense of the three parts that make up the geosphere.
The layer below the crust is the mantle. The mantle is both part of the lithosphere and the asthenosphere. The upper mantle is part of what forms the lithosphere, and the lower mantle makes up the layer called the asthenosphere. The asthenosphere is either partially molten, or melted, and convection currents occur here often.
The third layer, which makes up the center of our planet is called the core. It is made up of both liquid and solid iron-nickel alloy. The outer core, which is less preassurized, is the liquid-allow part. The inner core is the solid. |
|
|
Term
|
Definition
| The atmosphere is a thin, gaseous envelope that surrounds and protects Earth. It is also crucial for the biosphere, since it provides the air that we breathe, and protects us from the sun's intense heat and radiation. The atmosphere also produces weather and climate. |
|
|
Term
|
Definition
| The biosphere includes all life on Earth. This sphere depends on all the other spheres for life, and through countless interactions, this sphere maintains and alters the others. |
|
|
Term
| Describe the process of plate tectonics: |
|
Definition
Plate tectonics is the theory that proposes that Earth's out shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and the crust itself.
Plates can interact by means of divergent, convergent, and transform fault boundaries. Convergent plate boundaries create mountains, subduction zones, and volcanoes. Divergent boundaries create new oceanic lithosphere and reveal the paleomagnetism found in rocks. Transform-faul boundaires don't destroy lithosphere, but trigger earthquakes. |
|
|
Term
| Explain how Earth is a system: |
|
Definition
The Earth sustem is powered by energy from two sources. One, is the sun, and the other is Earth's interior.
The parts of the Earth System are linked together. Changes in one part produces changes in any or all of the other parts. |
|
|
Term
| What drives plate motion? |
|
Definition
| The uneven distribution of heat within earth. |
|
|
Term
| How are earthquakes caused? |
|
Definition
| An earthquake is a vibration of Earth produced by the rapid release of energy. Earthquakes are often caused by slippage along a break in Earth's crust. Forces within Earth slowly deform the crustal rocks on both sides of the fault. These forces cause the rocks to bend and store elastic energy. Eventually, the resistance caused by internal friction that holds the rocks together is overcome. The rocks slip at the weakest point (the focus). The movement will exert forces farther along the fault, where additional slippage will occur until most of the build-up energy is released. This slippage allows the deformed rock to snap back in place. The vibrations we call an earthquake occur as the rock elastically returns to its original shape. |
|
|
Term
| What is an earthquake's focus? |
|
Definition
| The focus of an earthquake is the place within earth where the earthquake originates. The released energy radiates in all directions from the focus in the form of seismic waves. It is much like the ripples produced when a stone is thrown into water. |
|
|
Term
| What is an earthquake's Epicenter |
|
Definition
| The epicenter is the location on the surface directly above the focus. |
|
|
Term
|
Definition
| Faults are fractures in Earth where movement has occured. Earthquakes are usually associated with large fractures in Earth's crust and mantle. |
|
|
Term
| What are P-waves? What can and can't they travel through? |
|
Definition
| P-waves are a type of body wave. They push and pull and temporarily change the volume of the object they pass through. They can go through either a liquid, solid, or a gas and are the fastest seismic waves. |
|
|
Term
| What are S-waves? What can and can't they travel through? |
|
Definition
| S-waves, like P-waves, are also a type of body wave. They forcefully shake and temporarity change the shape or position of the objects they pass through. They can only go through solids and CANNOT go through liquids. They are not the fastest, nor the slowest of the three types of seismic waves. |
|
|
Term
| What are Surface Waves? What can and can't they travel through? |
|
Definition
| Surface-waves are NOT a body wave. They travel OUTSIDE of Earth's interior. It affects anything on Earth's surface, and moves much like ocean-waves do. |
|
|
Term
| How are Earthquakes Measured? |
|
Definition
| Earthquakes are measured two ways-- based on intensity and magnitude. Intensity is a measure of the amount of earthquake shaking at a given location based on the amount of damage. Magnitudes are quantitative measurements that rely on calculations using seismograms. |
|
|
Term
| What are the two different scales scientists use to measure Earthquakes? |
|
Definition
-The Ritcher Scale
-Moment Magnitude |
|
|
Term
| How is a tsunami created? |
|
Definition
| Tsunamis form when a slab of ocean floor is displaced vertically along a fault. They also occur when the vibration of a quake sets an underwater landslide into motion. They are both fast (500-930 kilometers per hour) and dangerous. |
|
|
Term
| What are divergent boundaries? What landforms and/or physical features do they form? |
|
Definition
| Divergent Plate Boundaries are two lithospheric plates pulling apart from one another in the opposite direction. This often creatures ridges in the ocean, creating new oceanic lithosphere (called sea-floor spreading) |
|
|
Term
| What are convergent boundaires? What landforms and/or physical features do they form? |
|
Definition
| Convergent Plate Boundaires are two lithospheric plates colliding into one another. This often results in complex mountain-building and the formation of subduction zones which create both continental and island volcanic arcs. |
|
|
Term
| What are Transform boundaries? What landform and/or physical features do they form? |
|
Definition
| Transform fault boundaires are where two lithospheric plates are grinding past one another, heading in opposite directions of each other. This does not create nor destroy any of the lithosphere. |
|
|
Term
| What is the Principle of Superposition? |
|
Definition
| One of Steno's three relative dating principles. It merely states that in a undeformed sequence of sedimentary rock, each bed is older than the one above it, and younger than the one below it. Pretty basic... |
|
|
Term
| What is the Principle of Original Horizontality? |
|
Definition
| Another of Steno's principles. This one's also pretty straight-forward. It means that layers of sediment are generally deposited in a horizontal position. |
|
|
Term
| What is the Principle of Cross-Cutting Relationships? |
|
Definition
| The third and final of Steon's observations. Like the others, it is pretty easy to follow. It states that when a fault cuts through rock layers, or when magma intrudes other rocks and crystalizes, we can assume that the fault or intrusion is younger than the rocks affected. |
|
|
Term
|
Definition
| An index fossil is the name given to any remains or traces of an organism preserved from the geologic past that is widespread geographically, are abundant in number, and are limited to a short span of time. Index fossils are useful in correlating rocks in various regions. |
|
|
Term
| What determines if an organism will become a fossil? |
|
Definition
| Two conditions are necessary to insure fossilization: Rapid burial and possession of hard parts. |
|
|
Term
|
Definition
| Radioactivity is when nuclei are unstable and spontaneously begin to decay or break apart. |
|
|
Term
|
Definition
| A half-life is the amoutn of time necessary for one half of the nuclei in a sample to decay to its stable isotope. If the half-life of a radioactive isotope is known and the parent/daughter ratio can be measured, the age of the sample can be calculated. |
|
|
Term
| What is Radiometric Dating? |
|
Definition
| The procedure where scientists calculate he ages of rocks and minerals. |
|
|
Term
| What is radiocarbon dating? |
|
Definition
| Radiocarbon dating is used to date recent events. Living organisms all conain some carbon-14, the isotope for carbon. It is continually replaces until the organism dies. Radiocarbon dates for a dead animal/plant can be calculated by comparing the ratio of carbon-14 to carbon-12 in a sample. |
|
|
Term
| What are the three eras that make up the Phanerozoic Eon? |
|
Definition
| Paleozoic (ancient life), Mesozoic (middle life), and Cenezoic (recent life). |
|
|
