Enlarge / A seismometer on the atoll of Diego Garcia (left) can calculate ocean temperature with earthquakes close to Sumatra (proper). (credit score: Wu et al./Science)
Geophysics has proven that exact measurements and a bit of modeling can carry out wonders, like exhibiting us the detailed construction of the Earth’s inside although it’s inaccessibly buried beneath a whole lot of kilometers of rock. That is doable as a result of seismic waves produced by earthquakes subtly change velocity or path as they cross by totally different supplies. A brand new paper exhibits that one thing related can really measure small temperature modifications within the deep ocean.
An concept to make use of acoustic waves from man-made sources was really floated a number of a long time in the past however died out after some trials. A group led by Wenbo Wu on the College of Toronto realized that earthquakes might be taken benefit of in the identical approach, eradicating the costly logistics of continually setting off booms to get measurements, in addition to considerations concerning the results on marine life.
There are literally a number of kinds of seismic waves launched by earthquakes, and every behaves a bit otherwise. The P-wave (P for “major” as a result of it’s the primary to reach) is analogous to a sound wave, because it compresses the rock in the identical path it’s touring. So the place this wave reaches the seafloor or the bottom floor, the rock can behave like an enormous speaker, producing a really low-frequency sound wave within the air or water.Learn 11 remaining paragraphs | Feedback