GEO 101 Quiz 1

In what ways does continental crust differ from oceanic crust?

continental crust is thicker, less dense, more buoyant richer in light elements like N and K, poorer in dense elements such as Fe and Mg than oceanic crust.

Tectonic plates of rigid and brittle __________ move over a softer and ductile ___________ below.

lithosphere, asthenosphere

Because earth is a closed system:

there is a finite supply of resources and all waste and pollutants generated on Earth stay on Earth

Earth's interior is hot because

Formation of the Earth by accretion generated huge amounts of heat, from which the Earth is still cooling off and radioactive decay of unstable elements in the earth is a process that releases heat.

What is a result of planetary differentiation?

Light elements rose to form the crust; Heavy elements sank to form the core; Light lithosphere floating on denser asthenosphere

Explain why geologists believe that the Earth's core is made mostly of iron.

The average density of the Earth, as shown by its gravitational field, is significantly higher than the density of the mantle, which is known from a few direct observations of materials erupted from volcanoes and exposures of mantle rock at the surface. This is despite the fact that the mantle makes up most of the earth by volume. Therefore, the core must be very dense to explain the earth's average density. Iron is one element that would provide the needed density, and iron is known to be abundant in the solar system from studies of meteorites, making iron a likely candidate for the composition of the core.

Describe the Earth's internal structure in terms of both chemical composition and physical properties.

The core is solid and is made up of Fe and Ni. The outer core is liquid and rotates which is responsible for our magnetic field. The mesosphere is the lower mantle and it is The asthenosphere is ductile and the lithosphere and crust are solid. The mesosphere and the asthenosphere are composd of O, Si, Mg and Fe. The lithosphere is where the tectonic plates are located and they "float" on top of the asthenosphere. The lithosphere is solid but brittle like glass. The crust is solid and composed of O, Si, Al, Na, K, Ca.

Composition

The division of Earth's interior into core, mantle, and crust is used to describe differences in

Outer Core

The layer of the Earth that is thought to be a liquid.

How does the lithosphere differ from the asthenosphere?

The lithosphere is a rigid and brittle solid while the asthenosphere is a soft and ductile solid. The lithosphere is synonymous with the crust, while the asthenosphere is synonymous with the mantle.

Earth's atmosphere was once very similar in composition to the atmosphere of

Venus and Mars