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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A. cyan light. B. yellow light. C. blue light. D. none of the above
This wind-blown dust deposit (loess) from Tibet
A) was deposited by a huge flood of seawater that covered the land at the time of the dinosaurs.
B) began as clay and silt that were produced by grinding of rocks along ice-age glaciers.
C) forms a worldwide layer associated with a well-known extinction of dinosaurs.
D) All of these are correct.
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A) is the average of 24 temperatures taken an hour apart. B) is the difference between the day's high and low temperature. C) is the average of the maximum and minimum temperature for a given day. D) varies little from month to month.
The nations with the highest rate of contraceptive use (84%) are ________
A) Australia and Nepal B) South Africa and Botswana C) United States and Canada D) China and United Kingdom E) New Zealand and Denmark