Chapter 2 Problem 1 17
1. The earth consists of iron, oxygen, silicon and magnesium. This makes up about 90% of the earth’s elements. Jupiter and Saturn on the other hand consist mostly of volatile gases like water, methane and ammonia. These two planets retained their volatiles due to their greater gravitational force.
2. Scientist believe that the collision of earth with a smaller body caused the earth to tilt on it axis at 23 degrees. The blasting debris is said to have formed the moon. The period from the accretion of the earth to the formation of the oldest existing rocks can be retraced to the stratification or differentiation of the earth.
3. The newest model states that the earth’s outer core to be a very active and move in circulation. This is called plate tectonics.
4. The origin of earth’s magnetic field is a result of molten metal in the outer core that circulates around the inner core like a giant dynamo. Magnetism of the lithosphere supports the model of plate tectonics through the development of new oceanic crust that formed volcanism at the ridge crest in the prevailing polarity. This new crust was split apart and then moved in opposite directions. This explains new lithosphere at mid oceanic plate margins.
5. Gravity variations are present due to the rotation of the earth, topography and variations in density of near surface rocks. Isostatic equilibrium is based on the basis of isostasy which states that crustal masses establish a state of dynamic equilibrium with the mantle.
6. One evidence is the continental drift that made Pangea drift into the us known continents today. The next evidence is sea floor spreading which is demonstrated by alternately magnetized volcanic crustal rock. New crustal material was formed by volcanic eruptions by the crest of mid oceanic ridges and therefore slow lateral movement of the crust away from the ridges was occurring.
7. Divergent plate margins occur where rising convention currents in the asthenosphere almost reach the
2. Scientist believe that the collision of earth with a smaller body caused the earth to tilt on it axis at 23 degrees. The blasting debris is said to have formed the moon. The period from the accretion of the earth to the formation of the oldest existing rocks can be retraced to the stratification or differentiation of the earth.
3. The newest model states that the earth’s outer core to be a very active and move in circulation. This is called plate tectonics.
4. The origin of earth’s magnetic field is a result of molten metal in the outer core that circulates around the inner core like a giant dynamo. Magnetism of the lithosphere supports the model of plate tectonics through the development of new oceanic crust that formed volcanism at the ridge crest in the prevailing polarity. This new crust was split apart and then moved in opposite directions. This explains new lithosphere at mid oceanic plate margins.
5. Gravity variations are present due to the rotation of the earth, topography and variations in density of near surface rocks. Isostatic equilibrium is based on the basis of isostasy which states that crustal masses establish a state of dynamic equilibrium with the mantle.
6. One evidence is the continental drift that made Pangea drift into the us known continents today. The next evidence is sea floor spreading which is demonstrated by alternately magnetized volcanic crustal rock. New crustal material was formed by volcanic eruptions by the crest of mid oceanic ridges and therefore slow lateral movement of the crust away from the ridges was occurring.
7. Divergent plate margins occur where rising convention currents in the asthenosphere almost reach the