Whales sing and the earth answers. This isn't a poetic line, it's what scientist have found in a recent discovery.
Whales often use songs created from their fins to communicate with each other, also impact the earth with these noises - and it could prove useful for scientists. The sound of fin whales echo back from the seabed could become a useful tool for scientists studying the sediment and rock that make up Earth's crust, according to new research carried out in the northeast Pacific Ocean.
The songs are some of the strongest and most far-reaching vocalizations in the ocean, and with tens of thousands of fin whales spread out across the world, the calls could help add to existing scans or fill in gaps.
The study 'Seismic crustal imaging using fin whale songs' was published in Science magazine.
The study analyzes fin whale songs recorded at ocean-bottom seismometers in the northeast Pacific Ocean and show that in addition to the waterborne signal, the song recordings also contain signals reflected and refracted from crustal interfaces beneath the stations.
From the data, the scientists constrain the thickness and seismic velocity of the oceanic sediment and basaltic basement and the P-wave velocity of the gabbroic lower crust beneath and around the ocean bottom seismic stations. The abundant and globally available fin whale calls may be used to complement seismic studies in situations where conventional air-gun surveys are not available.
The study is authored by Václav Kuna, a seismologist, who found it quite by accident.
In 2019 Kuna was perusing recordings from dozens of seismometers at the bottom of the northeast Pacific Ocean, when he kept finding strange noises: one-second chirps, repeating every 30 seconds or so.
This staccato symphony turned out to be the songs of fin whales. “Because I’m a seismologist, I wasn’t just like, oh, fin whales, that’s cute,” said Dr. Kuna, then a doctoral student at Oregon State University, tells New York Times.
Dr. Kuna, now at the Institute of Geophysics of the Czech Academy of Sciences, and John Nabelek of Oregon State have discovered that fin whale song can be used to peer into the oceanic crust. Using this biological source of seismicity, they found they could see 8,200 feet below the seafloor, through sediments and the underlying volcanic rock.
“It’s a nice example of how we make use of the data the planet provides for us,” Jackie Caplan-Auerbach, a seismologist and volcanologist at Western Washington University told New York Times.