Describe what trenches and island arcs are. Why are these features linked with large earthquakes and
tsunamis? What will be an ideal response?
ANS:Answer
should include:
? Trenches are arc-shaped depressions in the seafloor. Island arcs are curving chains of
volcanic islands and seamounts. Both of these bathymetric features are found at
converging subduction zones.
? These are common on active margins because there is subduction occurring. The oceanic
crust is melting and plunging back into inner Earth. This creates the geological activity.
The crust does not always subduct smoothly which can cause earthquakes. Since these
earthquakes originate underwater, there are possibilities of tsunamis happening as well.
? The trench wall's steepness can indicate the direction of the subduction. The island side
of a trench tends to be steeper.
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The blue part of a flag will appear black when illuminated with
A. cyan light. B. yellow light. C. blue light. D. none of the above
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D) All of these are correct.
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