Infrasound, also known as low-frequency sound, describes sound waves with a frequency below the lower limit of human audibility. Multidisciplinary projects are hard due to their complexity. But its failures were also large and tragic. It was none of those. We were a little bit surprised about that.
Infrasound is less than the surface of our planet.
( z0 have-quant :ARG1 ( z1 earthquake ) :ARG3 ( z2 less ) :ARG4 ( z3 surface :part-of ( z4 planet :poss ( z5 we ) ) ) )
(z0 / have-quant-91
    :ARG1 (z1 / earthquake)
    :ARG3 (z2 / less)
    :ARG4 (z3 / surface
              :part-of (z4 / planet
                           :poss (z5 / we))))
Infrasound is less than the surface of our planet .
z0 :ARG1 z1
z0 :ARG3 z2
z0 :ARG4 z3
z4 :poss z5
z3 :part-of z4