Vocabulary[edit | edit source]
- Faults - Cracks in the Earth's crust.
- Seismographs - Delicate devices that can track vibrations during earthquakes all around the crust.
- Bench Marks - A plaque that tells the exact location and elevation of a place.
- Geologists - People who study the earth
- Paleontologists - People who study ancient life
- Geology - The way of studying earth
- Paleontology - The way of studying ancient life
- Plates - Pieces of Earth's crust
- Mantle - Below the Earth's crust, has solid gooey rocks
- Convection Center - Stage of sinking and rising (the mantle pushing the plates)
- The Earth's core - Two parts of the core, a liquid outer core and a solid inner core
- Tension - Stretches the Earth's crust
- Shear - Twisting or Turning the Earth's crust
- Compression - Squeezing or Pushing the Earth's core
- Fold Mountains - Mountains made of crumpled and folded layers of rock
- Magma - Holt molten rock deep below Earth's surface
- Lava - When Magma hits the surface of the Earth
- Surtsey - An Island near Iceland, is forming from an undersea volcano
- Fault-block Mountain - Blocks of crust moving along a fault
- Basin and Range Province - A range of fault-block mountains
Earth's crust[edit | edit source]
Earth's crust is constantly moving, if not in one place then in another. Sometimes it moves quickly enough to felt or seen, or even both! Earthquakes are related to cracks in the Earth's crust called faults. The faults may have formed from earlier Earthquakes.
Delicate devices called Seismographs can record this motion at locations all around the crust. Most of the time, however, the crust moves very slowly. Rocks can move slowly on either side of a fault over centuries. To measure the crust movement, surveyors measure elevation---how high a place is above sea level. They leave plaques called bench marks that tell the exact location and elevation of a place.
People who study the earth are geologists.
Plate Tectonics[edit | edit source]
The crust is the hard surface of Earth. The crust is also the top of the Lithosphere. Compared with the distance to Earth's center, it is very thin. It is only about one-thousandth of Earth's thickness.
Mantle[edit | edit source]
Under the crust is the mantle, Earth's thickest layer. The rock material here is solid. However it flows like liquid. The rock material in the mantle is in motion, something like heated water in a pot. It rises and pushes against the bottom of the crust. This movement causes Earth's crust to break into pieces called plates.
The Convection Center is where the Mantle pushes against the crust by sinking and rising.
Earth's core[edit | edit source]
Below the mantle is Earth's core, there is an outer liquid core and an inner liquid core.