P-waves refract at the boundary between inner and outer core because
A. there is a change of phase between inner and outer core.
B. they lose speed.
C. they gain speed.
D. there is a change in chemical composition between inner and outer core.
Answer: A
You might also like to view...
In which of the following locations in the United States are dryline thunderstorms most common?
A. Great Plains B. California C. Rocky Mountains D. desert southwest
If new seafloor is being created at spreading centers, why don't we find a lot of old oceanic crust on the surface of the Earth? Because oceanic crust is being ____ where it collides with continental plates.
A ) folded B ) pushed up C ) subducted D ) vaporized
Why did federal laws limiting pollution of rivers and streams not prevent the pollution and the fires on the Cuyahoga River from 1868 to 1969?
A) There were no federal regulations of water pollution at that time. B) This pollution went undetected by agents overwhelmed by the amount of work. C) The federal laws preventing water pollution did not apply to the state where this occurred. D) These industries that polluted the water had been repeatedly fined for polluting and continued to ignore the laws.
The Nile River supports significant amounts of __________.
Fill in the blank(s) with the appropriate word(s).