Although we don't know for sure, changes in the strength and orientation of earth's magnetic field are most likely due to
A) fluctuations in outer-core convection.
B) variations in sea-floor spreading rates.
C) the total number of mantle hot spots.
D) changes in the velocity of subducting plates.
Answer: A
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A fault (F) breaks three layers of sedimentary rock (S). An igneous intrusion (I1) has broken through the bottommost layer of rock. A second igneous intrusion (I2) has moved up the fault and pooled on top of the uppermost layer of rock. Which event would be considered the youngest?
Eastern North American areas such as Missouri are at risk of suffering _______________ earthquakes
Indicate whether this statement is true or false.
Modern tsunami warning systems primarily use ________.
A. webcams and airborne drones B. sea surface buoys and ocean bottom pressure sensors C. spotters in airplanes D. LIDAR and reports from Coast Guard ships E. satellite photography and radar
Flying squirrels competing with each other for truffles is an example of ________
A) exploitation competition B) interspecific competition C) habitat competition D) interference competition E) intraspecific competition