The tool that would be most useful to him would be a seismometer. It is an<span> instrument that measure motion of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions. Hope this answers the question. Have a nice day. </span>
Answer:
psychrometer
Explanation:
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I would say the topic of such a study would be paleomagnetism and perhaps its effect on plate tectonics because when the seafloor spreads at the mid-ocean ridges, magnetized stripes of rock, symmetrical on either side of the trench form and they record changes in the earth's magnetic poles at certain times so can be dated to help show the rate of spreading of the seafloor at these locations.