Why is Earth's continental crust lower in density than seafloor crust?
A) Continental crust comes from volcanoes while seafloor crust comes from geysers.
B) Continental crust is made from a low-density volcanic rock called basalt.
C) Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones.
D) Continental crust comes from Earth's inner core while seafloor crust comes from the outer core.
C
You might also like to view...
A hunter fires a bullet from a horizontally—held rifle while simultaneously dropping another bullet from the side of the rifle. The bullet to hit the ground first is
A) the dropped one. B) the fired one. C) both hit at the same time
Which of the following is true of early astronomers?
A) They knew that there were many other galaxies in the Universe. B) They thought the entire Universe consisted of Earth, the Sun, the Moon, and five other planets. C) They knew that the planets were made of rock and gas, much like Earth. D) They thought that stars were other objects like the Sun and that we lived inside a galaxy.
____ are crucial in determining the distance to objects that are far away, but still in the Milky Way galaxy
a. RR Lyrae stars b. Cepheid variable stars c. O and B stars d. Emission nebulae e. Supernovae
Radio waves have wavelengths that are ________ visible wavelengths.
A. slower than B. the same energy as C. faster than D. longer than E. shorter than