THE EARTH STRUCTURE

STRUCTURE AND COMPOSITION OF THE EARTH

DAKOTA RAMOS - JULIA CLAVO

SOME QUESTIONS

- How many layer does the Earth consist of?Geosphere consist of inner core (solid), outer core (liquid), mantle and cortex. - How do continental and oceanic crusts differ? Oceanic crust is thinner and denser tan continental crust. Oceanic crust is darker in color and denser (more mafic). The continental crust is lighter in color and less dense (more felsic). - What is the lithosphere? A structural unit, which is about 100km thick is in the crust and the top of the upper mantle. - Why does the magnetosphere allow life to exist on Earth? Is like a protective screen, it deflects the majority of the solar winds that would drag gases away from our atmosphere if they reached the Earth.

CRUST

The crust is the upper surface layer of the Earth, is the thinnest.-Cotinental crust: consists of granite, plus metamorphic and sedimentary rocks. -Oceanic crust: is thinner and denser, consists of basalt, a volcanic rock, which is produced in mid-oceanic ridges.

ATMOSPHERE

The atmosphere is a mixture of gases that surrounds the Earth. It helps make life possible by providing us with air to breathe, shielding us from harmful ultraviolet (UV) radiation coming from the Sun, trapping heat to warm the planet, and preventing extreme temperature differences between day and night.

UPPER MANTLE

The upper mantle exists between the crust and the transition zone. The very uppermost portion of the mantle is part of the lithosphere, a layer that includes the crust. This layer is hard and brittle and is where tectonic plates exist.

INNER CORE

The inner core is the dense center of Earth. Theories on the formation of Earth suggest that the inner core is composed of iron and nickel heated up to a temperature of around 9,800 degrees F.

LOWER MANTLE

The lower mantle is the region 400 to 1,800 miles below the Earth's surface, made of solid rock. The lower mantle lies beneath the upper mantle and surrounds the outer core. The lower mantle is characterized by extremely high pressure and temperatures of around 7,000° F.

OUTER CORE

The outer core is the only liquid layer, and is mainly made up of the metals iron and nickel, as well as small amounts of other substances. The outer core is responsible for Earth's magnetic field. As Earth spins on its axis, the iron inside the liquid outer core moves around.