What is the evidence for Earth's central core being solid?
What will be an ideal response?
Earth's solid central core is revealed by the differences in P- and S-wave propagation through Earth's interior. As these waves encounter the boundary at 2900 km, a very pronounced wave shadow develops. P-waves are both reflected and refracted at the boundary, but S-waves are only reflected. S-waves cannot travel through liquids, implying a liquid outer core. As P-waves propagate through the outer core, there is a depth at which there is a sudden increase in speed. The faster traveling wave indicates a solid inner core.
You might also like to view...
Briefly explain how magnetic reversals in oceanic crust and fossils in ocean sediments are used to
construct a magnetic time scale. What will be an ideal response?
True or False: According to the Continental Drift hypothesis the continents and ocean basins on the same plate move together
Indicate whether this statement is true or false.
As of 2014, more than 20,000 species have been placed on the Red List because
A) they are at high risk of extinction as determined by criteria similar to the criteria for designating endangered species in the United States. B) these species are considered the most invasive and ecologically disruptive species in their regions. C) according to the Aichi Biodiversity Targets, they will all become extinct by 2020. D) international legislation is underway to protect their habitats from further development.
Research performed by Edward O. Wilson on ____ has been applied to the study and understanding of other social organisms, including humans.
A. ants B. worms C. bees D. chimpanzees E. elephants