Even though the sea is alive with the buzz of the marine life, the whine of the ships cruising through it, and the soft lull of the waves, it is the lowest pitched sound emanating from the Caribbean Sea that has the researchers intrigued.
The pitch of the sound is too low to be detected by the human ear. The sound was first picked up by the satellites in space. The scientists claim that they have never heard anything like it before.
The Caribbean Sea is situated in the southeast of the Gulf of Mexico. The Sea is an important route in the global transportation belt and feeds the Gulf Stream. The research team from the University of Liverpool was studying the dynamics of the sea when they observed a strange phenomenon. One of the team members, Chris Hughes, explained their observations:
“We were looking at ocean pressure through models for quite different reasons, and this region just didn’t work. It felt like a sore thumb.”
Once weird oscillation appeared in the models, the team tried to record the incident in the ocean. The team linked the pressure data from the bottom of the Caribbean Sea recorded from 1958 to 2013 with tide gauge reports and related it to the data from NASA’s Grace satellite. The researchers were thrilled to learn that the basin of Caribbean Sea was actually behaving like a huge whistle. As Hughes puts it:
“You have a current that flows east to west through the Caribbean Sea. It’s very narrow and quite strong. Just like a narrow jet of air, it becomes unstable and creates eddies.”
On striking the western boundary of the basin of the Caribbean Sea, these waves disappear only to reappear at the eastern end. This phenomenon is known as a “Rossby Wormhole.” The studies show that the waves of some specific shapes can resonate on collision with the western wall and produce sound. The same phenomenon produces a sound from the whistle.
The extreme vastness of the basin of the Caribbean Sea creates a very low resonant frequency. The waves propagate from the eastern bank to the western bank in 120 days. The resulting impact produces an A-flat tone, around 30 octaves below the bottom of the piano.
You can listen to an amplified version of the sound in this clip:
The phenomenon was detected from space because the gravity field of the Earth alters as the pressure changes are transferred across the basin. The scientists hope that the monitoring of this phenomenon will help in keeping a closer eye on the coastal flooding and its prediction.