INT.SCI - LAYERS OF EARTH

• Earth is divided into four major layers—the _____,______, _________, and _________ each with distinct properties.

  Crust, Mantle, Outer Core, Inner Core
• The crust and the uppermost part of the mantle comprise the ___________, a rigid layer that can break under stress.

  Lithosphere
• The lithosphere is composed of major and minor blocks, called ________ ______, that interact and create the tectonic activities.

  Tectonic Plates
• Below the lithosphere is the ____________, which is about 180km thick and contains hot, molten rocks or magma.

  Asthenosphere
• The asthenosphere can deform and reshape driven by heat energy, which circulates as __________ ________, traveling upward from hot lower mantle to the cooler upper mantle.

  Convection Currents
• The outermost layer of Earth where life exists is called the _____.

  Crust
• The crust that makes up the continents is called the ___________ _____ and is about 40 to 70 km thick.

  Continental Crust
• The crust that underlies the ocean floor is called the _______ _____, and it has an average thickness of 5 km.

  Oceanic Crust
• ______ ______, an English astronomer and mathematician, theorized that Earth is hollow and that there are inner concentric layers below the crust that float in gas.

  Edmund Halley
• Below the crust is a semisolid, rocky, and very hot later called the ______.

  Mantle
• The core has two distinct layers:

  Liquid Inner Core and  Solid Inner core
• The _____ ____ is the only player of Earth that is liquid, which is made up of molten nickel and iron.

  Outer Core
• The _____ ____ has a diameter of about 1220 km and is composed mostly of solid iron. It is extremely hot; it's temperature is recently estimated to be about 6000°C.

  Inner Core
• It is the interface between the crust and the upper mantle.

  Mohorovicic Discontinuity
• This interface marks the boundary between the lower mantle and the outer core.

  Gutenberg Discontinuity
• This interface is located between the liquid outer core and the solid inner core.

  Lehmann Discontinuity
• He is a Croatian Geophysicist who concluded that the crust was made of a less dense material and that the mantle consisted of a much denser material.

  Andrija Mohorovicic
• In what year did Andrija Mohorovicic,  concluded that the crust was made of a less dense material and that the mantle consisted of a much denser material?

  1909