Earth's interior is generally divided into three major layers: the crust, the mantle, and the core.
The hard, brittle crust extends from Earth's surface to the so-called Mohorovicic discontinuity, nicknamed the Moho. The Moho is not located at a uniform depth, but about 10 kilometers (6 miles) below the seafloor and about 35 kilometers (22 miles) beneath the surface of continents.
The mantle is divided from the core by the Gutenberg discontinuity, about 2,880 kilometers (1,798 miles) beneath Earth's surface. The outer core is molten and liquid iron and nickel, while the inner core is solid and much more dense than either iron or nickel at the surface.
Which lies deeper beneath the Earth's crust—the Gutenberg discontinuity or the Moho?
What region of Earth's interior do you think is the most rigid and brittle?
Which region of Earth do you think is the hottest?
Term Part of Speech Definition Encyclopedic Entry brittle Adjective
fragile or easily broken.
one of the seven main land masses on Earth.
Encyclopedic Entry: continent core Noun
the extremely hot center of Earth, another planet, or a star.
Encyclopedic Entry: core crust Noun
rocky outermost layer of Earth or other planet.
Encyclopedic Entry: crust dense Adjective
having parts or molecules that are packed closely together.
our planet, the third from the Sun. The Earth is the only place in the known universe that supports life.
Encyclopedic Entry: Earth Gutenberg discontinuity Noun
point between the Earth's mantle and the core below.
middle layer of the Earth, made of mostly solid rock.
Encyclopedic Entry: mantle Mohorovicic discontinuity Noun
point between Earth's crust and the mantle below. Also called the Moho.
surface layer of the bottom of the ocean.
liquid that is thick and sticky.
space an object occupies.