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Currently most geologists favor the theory that earth formed via accretion from a protoplanetary cloud about 4.57 billion years ago.
The material that formed the terrestrial planets like Earth contained a concentration of short-lived radionuclides that was high enough that the radiation emitted by their decay heated the bodies up to their melting temperature. An additional source of energy for Earth is believed to be the so-called "giant impact", the collision of the proto-Earth with a roughly Mars-sized protoplanet in the early history of our planet. It is thought to have resulted in the complete melting of the upper 100s of km of the Earth.
In the its molten stage the Earth completed its differentiation (separation of elements that chemically are unsoluable within each other in large quantities) into a metal core and a silicate mantle.
As the Earth is loosing heat into space the inner part of the metal core started to crystallize and now forms the (I) solid inner core.
(II) The outer metal core is still liquid and is believed to play a key role in generating the Earth's magnetic field.
(III) The mantle is the shell around the core which is currently not very well understood in terms of its exact composition and rheological (the way that the material reacts on stresses leading to deformation) behaviour. Most geologists agree that the whole mantle or at least a portion of it convects and by this process the mantle in mixed and portions of the mantle ascend to rather shallow (i.e. close to the surface) levels and undergo partial melting. Formally the mantle can be subdivided into several zones depending on the stability of certain mineral phases and one often finds the subdivision into upper and lower mantle at a depth of about 660 km.
(IV) The melt extracted from the mantle forms most of the oceanic crust that we see today and is the first step to the creation of continental crust as well. The formation of continental crust is far more controversial than that of oceanic crust but involves melt extraction from the mantle and several remelting events of the basalts that crystallized from these melts. The continental crust as we know it today is buoyant, i.e. it "floats" on the mantle because of its lower density and builds stable land masses whereas the oceanic crust is continuously recycled and sinks into the mantle in subduction zones.
What else can I help you with?
What are the four colors of the earths layers?
brown everything is a mess of brown and purple
Which scientist classified elements into four categories gases metals nonmetals and earths?
Any scientist; this classification don't exist.
How do scientist believe the earths four layers were formed?
when this earth cooled from being hot, all the Iron and Nickle get concentrated inside earth forming inner two layers Inner solid core and outer liquid core. Then with the passage of time earth solidifies gradually and mantle solidifies and now at this stage our crust the outer most part of earth look like its final product.
What are four main layers of earths atmosphere?
The four main layers of Earth's atmosphere are Toposphere, Stratosphere, Mesosphere, and Thermosphere. (The Thermosphere ends at 62 miles from earth's surface. or, where space starts.TroposphereExosphereIonosphereOzonosphere
What are four layers that make up Earths atmosphere?
lower core, upper core, mantle, and crust
What is the thickness of the earths mantle?
The earths mantle is one of the four major layers, laying between the crust and the outer core. At 2885 kilometers, it is the thickest layer.
How did scientists believe that there were earths four layers?
Scientists believe that Earth has four layers (crust, mantle, outer core, inner core) based on seismic waves produced by earthquakes and volcanic activity. These waves travel through the Earth at different speeds and behave differently depending on the properties of the material they travel through, allowing scientists to infer the presence of distinct layers with varying densities and compositions. This model helps explain Earth's structure and how it influences geological processes.
How many layers of muscle are there in the foot?
there are 44444444444444444444444445555555555555555555555555555555555577777777777777777 layers of skin on your feet
What characteristics scientist use to define four layers of earth atmosphere?
they use the troposphere, stratosphere, mesosphere, and thermosphere
What are the earths four atmosphere layers called?
Troposphere, stratosphere, mesosphere, thermosphere (containing ionosphere), exosphere.
Give at least one characteristic of each if the four main layers of earths atmosphere?
In the four main layers of the earth\'s atmosphere weather occurs in the troposphere, airplanes fly in the stratosphere, meteors are burned in the mesosphere, and satellites are placed in the thermosphere.
Who was the scientist classified elements into four categories gases metals nonmetals and earths?
The scientist who classified elements into the four categories of gases, metals, nonmetals, and earths was Antoine Lavoisier. In the late 18th century, Lavoisier played a pivotal role in the development of modern chemistry and is often referred to as the "father of modern chemistry." His systematic approach to categorizing elements laid the groundwork for future classification systems.
