Suspecting that oil lies under the seabed is one thing. Proving it is quite another.
By the mid 1950s, there was an all-out attempt to discover was what thought to be very large deposits of oil and gas both off shore and under the desert of Abu Dhabi.
Everything about the search for oil is difficult and expensive, even if the rewards can be great. This is all the more so at sea, when huge drilling rigs must be towed into place to drill for what may, or may not, be many metres beneath the waves.
Using sound is one way of selecting the best place to search. The photograph shows the moment an explosive was detonated by a seismic survey ship, which carried equipment to measure the way sound travelled through the rock under the seabed - an indication that oil might be present.
In the case of Abu Dhabi, the surveyors got it right first time, with the ADMA Enterprise rig hit oil in what would be the Um Shaif field in March 1958.
Explosives are no longer used in off shore oil surveys for environmental reasons. What is good for the economy is much less so for marine wildlife.