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☆☆☆☆☆Continental drift is the movement of the Earth's continents relative to each other. The hypothesis that continents 'drift' was first put forward by Abraham Ortelius in 1596 and was fully developed by Alfred Wegener in 1912. However, it was not until the development of the theory of plate tectonics in the 1960s, that a sufficient geological explanation of that movement was found.
Continental drift referred to the concept that the Earth's continents were once part of a large supercontinent and had subsequently split apart and arrived at their present destinations.
Continental drift theory has been replaced by the science of plate tectonics, an all inclusive explanation of the process of continent movements, crust creation, lithologies, subduction, the rock cycle, and so on. The engine behind plate tectonics is heat from the interior of the Earth. This heat is a combination of heat from radioactive decay, remnant heat from Earth's formation process, and crushing pressures from its mass.
Heat rises through the mantle outward toward Earth's surface. In a layer of the upper mantle known as the asthenosphere, the solid rock is plastic-like, enough so that the rock slowly flows in a current. The current rises to reach its maximum height at a weakness in the hard uppermost mantle with attached crust known as the lithosphere. At these points, the hot mantle rocks melt from the lowering of lithostatic pressure and rises to form new crust at the mid-ocean ridges. As new material is added at the ridges, the tectonic plates on either side move apart. Over time this causes the continents located on the plates to "drift' apart.
At the other end of the current, older, denser crust is being pushed under less dense crustal plates and less dense oceanic plates, in a downward trajectory toward the mantle, where it melts and gradually becomes part of the mantle rock once again. The Pacific Ocean is gradually shrinking due to the subduction of its boundaries in an area known as the Ring of Fire. One day it will cease to exist, and once again there will exist a supercontinent.
Maycomb, Alabama
masozoic era
D. One eight
Calpurnia is the Finch's cook.
the 11 yr old is a girl or a boy?
The Pacific Ocean area. The Ring of Fire runs along the western part of America all around to Asia and Oceania.
The time it takes for half the sample to decay is called the half-life.
The time it takes for half the sample to decay is called the half-life.
The time it takes for half the sample to decay is called the half-life.
The time it takes for half the sample to decay is called the half-life.
Because the core is solid and hot, it radiates natural heat to the upper layers of the earth resulting to convection current. This current causes the movement of the tectonic plate of the earth resulting to earthquake
- Lower mantle: Near outer core
- Inner core: Dense and solid
- Outer core: Liquid
- Upper mantle: Moves the crust
Earthquakes are tremors or vibrations in the Earth's crust that are caused by the build up or accumulation of pressure (more correctly termed stress).
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The Earth's crust, or lithosphere (hard outer surface) is made up of "tectonic plates", or large plates. There are about 7 major plates and many smaller plates, around 100 km thick, which sit upon a lower soft layer (the asthenosphere). The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.
This accumulation of stress causes the rocks that make up the crust to deform elastically. This is very similar to what happens when you squash or stretch a spring and causes a form of energy to be stored in the rocks of the crust - technically described as elastic potential energy.
When this stress gets too large, it exceeds the strength of the rocks in the crust and causes a brittle failure. Brittle failures are failures where fractures form through the material. As these have been happening for a long time, the earth's lithosphere is already fractured. These fractures are known as faults and as these represent zones of weakness within the lithosphere, it is along faults where the majority of earthquake occur when they slip suddenly.
This sudden brittle failure causes all of the elastic potential energy to be released at one time in the form of seismic waves, just as if a spring or elastic band that was being stretched suddenly snapped.
These seismic waves cause the tremors that people feel on the surface and which can cause damage to buildings and other structures.
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The Earth's crust, or lithosphere (hard outer surface) is made up of "tectonic plates", or large plates. There are about 7 major plates and many smaller plates, around 100 km thick, which sit upon a lower soft layer (the asthenosphere).
When these plates move against each other along plate boundaries (where two plates meet) or along faults (a rift), an earthquake occurs. This may be through a variety of movements: sideways, up and down or apart. This causes anything upon the upper surface, above the earthquake, to also shift, whether they be buildings, roads, bridges, railways, etc.
What you actually feel when you feel the shaking of an earthquake are the seismic waves.
There are three types of seismic waves and they are determined by the properties of the rock through which they travel:
P-waves (compressional waves) or primary waves are the first waves: they travel the fastest and can travel through everything.
Then the S-waves (shear waves) or secondary waves come: they move slower and cannot travel through liquids.
At last the Surface-waves come. They are the slowest and they cause the biggest damage. Often it is when the surface-waves come that the buildings collapse.
An earthquake describes when the earth moves the ground under your feet. It can slide it from side to side or move it a few feet in one direction. It can lift it up in one place and make it sink in another. The results of this are quite visible in and near Anchorage, Alaska. One street in that town shows where an earthquake make the ground fell. Driving south, dead trees stick up out of a lake where the ground fell below sea level. Earthquakes are caused when faults or cracks in the earth's shell suddenly slip past each other. When they jerk, they move a lot of land with them. That makes the earth tremble. Sometimes it damages buildings.
The official definition for the word earthquake is "a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action." knowing these earthquakes happen almost everywhere they do most take place in the U.S
in the state of California just a (FYI)
tectonic plates- move in 3 ways
1. collide w/ eachother
2.seperate from eachother
3. slide against eachother
when plates are moved to the breaking point it causes an eartquake
an earthquake is a seismic wave
Americans call their fathers Dad, Daddy, or Pop/Papa. In some families, the children address the father as 'Sir.'
The Mid-Ocean idge,in the middle of North America and Europe
Crust,mantle,outer core, inner core
The aesthenosphere, which is located in the top part of the Earth's mantle is the layer lying underneath the tectonic plates. Collective movement in these plates cause a gradual rise in the aesthenosphere, thereby resulting to land elevation.
Pandora
WHERE: earthquakes can happen any where
WHEN: there are no time when when earthquakes can or can't happen
A.
Precambrian Time - Paleozoic Era - Mesozoic Era - Cenozoic Era
B.
Cenozoic Era - Paleozoic Era - Mesozoic Era - Precambrian Time
C.
Mesozoic Era - Paleozoic Era - Precambrian Time - Cenozoic Era
D.
Paleozoic Era - Precambrian Time - Mesozoic Era - Cenozoic Era
