Earth's Interior and Structure Quiz

Crust

• The crust is the outermost layer of the Earth, composed mainly of two types of rock: granite (continental crust) and basalt (oceanic crust).
• Continental crust has an average thickness of 30 to 70 kilometers, while oceanic crust ranges from 6 to 12 kilometers.
• Continental crust is primarily made of silica and aluminum, referred to as 'Sial', whereas oceanic crust consists mainly of silica and magnesium, known as 'Sima'.
• The density of continental crust is approximately 2.6 to 2.7 g/cm³, compared to oceanic crust which is denser at about 2.8 to 3.0 g/cm³.
• The lithosphere, consisting of the crust and the upper mantle, is broken into tectonic plates.

Mohorovicic Discontinuity (Moho)

• The Mohorovicic Discontinuity marks the boundary between the crust and the mantle.
• Average depth of the Moho is about 8 kilometers beneath ocean basins and approximately 32 kilometers beneath continents.
• Discovered in 1909 by Croatian seismologist Andrija Mohorovicic.
• Project Mohole aimed to reach the Moho but was abandoned in 1966 after drilling 183 meters.
• Significant research includes the Kola Borehole, reaching 12,260 meters deep in 1989, and the Japanese vessel Chikyu, which drills into sub-oceanic regions.

Mantle

• The mantle is the thickest layer of the Earth, located beneath the crust, comprising about half of the Earth's mass and made of hot, dense, semi-solid rock.
• The asthenosphere, a fluid layer within the mantle, facilitates convection currents that cause lithospheric plate movement.
• The upper mantle contains elements like chromium, iron, silicon, and magnesium ('Crofesima').
• The mesosphere is the lower part of the mantle, where rocks remain solid despite extreme heat.
• The lower mantle, the densest and hottest layer, is composed of nickel, iron, silicon, and magnesium ('Nifesima').

Core

• The Earth's core is the innermost layer divided into the outer and inner core.
• The outer core is a fluid layer primarily composed of chromium and iron, termed 'Crofe'.
• The inner core is a solid sphere with a radius of about 1,216 kilometers and temperatures comparable to the Sun's surface.

Discontinuities

• Gutenberg Discontinuity occurs at a depth of approximately 2,900 kilometers below the Earth's surface, separating the mantle from the core.

Test your knowledge about the Earth's interior, including the crust, mantle, and core layers. This quiz covers key concepts such as the Mohorovicic and Gutenberg discontinuities. Dive in to learn more about the fascinating structure of our planet!