UNIVERSE
PLANETARY INTERIORS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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atmospheric pressure, gravity, water, and oxygen
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plate-tectonics, seismic waves, continental drift, and gravity
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decaying uranium, friction from iron and nickel, gravity’s pressure, leftover heat formation
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density of earths core, the location of the sun, the motion of the ocean, and wind
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Detailed explanation-1: -There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements.
Detailed explanation-2: -Radioactive potassium, uranium and thorium are thought to be the three main sources of heat in the Earth’s interior, aside from that generated by the formation of the planet.
Detailed explanation-3: -Many geologists believe that as the Earth cooled the heavier, denser materials sank to the center and the lighter materials rose to the top. Because of this, the crust is made of the lightest materials (rock-basalts and granites) and the core consists of heavy metals (nickel and iron).
Detailed explanation-4: –Kinetic or friction heat: It is produced between the outer core and the mantle. It is the heat energy that is released as a result of the friction produced by the different response of the outer core and the lower mantle face to the force fields generated by the Moon and the Sun (tidal forces).
Detailed explanation-5: -The outer core’s temperature is so hot that it melts the metal. The inner core is solid metal.
Detailed explanation-6: -So why has this heat not all been lost to space in the past 4.5 billion years? The Earth is still so hot inside in large part because its surface is too small, relative to its volume, for this heat to escape. The amount of heat energy is proportional to the mass (or the volume, since mass is proportional to volume).