Q 01/05

Which is the correct order of Earth's layers from the surface inward?

A) Crust, outer core, mantle, inner core

B) Crust, mantle, outer core, inner core

C) Mantle, crust, inner core, outer core

D) Crust, mantle, inner core, outer core

Answer · why

B) Crust, mantle, outer core, inner core

The mantle is by far the thickest layer at about 2,890 km, and the outer core is liquid while the inner core is solid.

Q 02/05

Which Danish seismologist discovered in 1936 that Earth has a solid inner core?

A) Beno Gutenberg

B) Inge Lehmann

C) Andrija Mohorovičić

D) Harry Hess

Answer · why

B) Inge Lehmann

The inner core is a ball of mostly iron and nickel about 1,220 km in radius, sitting inside a liquid outer core about 2,260 km thick.

Q 03/05

The boundary between Earth's crust and mantle is named after which scientist?

A) Gutenberg

B) Wegener

C) Richter

D) Mohorovičić

Answer · why

D) Mohorovičić

The 'Moho' is spotted by a jump in seismic wave speeds; oceanic crust above it is only 5 to 10 km thick.

Q 04/05

What is Earth's mean radius, to the nearest kilometre?

A) 6,371 km

B) 6,871 km

C) 7,371 km

D) 7,871 km

Answer · why

A) 6,371 km

Its average density of 5.515 grams per cubic centimetre makes it the densest planet in the solar system.

Q 05/05

Which German meteorologist proposed the theory of continental drift in 1912?

A) Max Planck

B) Alfred Wegener

C) Wilhelm Wien

D) Emil Wiechert

Answer · why

B) Alfred Wegener

He noticed the coastlines of Africa and South America fitted like puzzle pieces; the idea was ridiculed and he died on a Greenland expedition in 1930,...