The way whales’ songs return from the seabed could be a useful tool for scientists studying the sediment and rock that make up the crust. of the Earth, according to a new study conducted in the northeast Pacific.
These songs are on some of the strongest and most widespread voices in the ocean, and with tens of thousands of whales scattered around the world, the calls could help adding to existing scans or even filling in gaps where it is more difficult or even dangerous for marine life to use the conventional airgun approach.
Seismometers on the ocean floor can be used to pick up echos and variations of whale calls, revealing the thickness of the bark below as well as other seismic information that is helpful to scientific study.
(Kuna et al., Science, 2021)
“People in the past have used whale whales to track whales and study whale behavior,” says geologist John Nabelek of Oregon State University.
“We thought we might be able to study the Earth using these calls. After every whale call, if you look closely at the seismometer data, there’s a response from the Earth.”
Nabelek and his colleagues were studying earthquakes near the Blanco Break Zone off the coast of Oregon, using a network of 54 seismometers, when they noticed strong signals on the instruments corresponding to the presence of pigs- marine in the area.
A study of more than six calls showed that the subaqueous songs – which can be as tall as large vessels, and last 10 hours or more – traveled through the underwater ocean like seismic waves, before being exposed and removed by ocean sediment, the basalt cover below, and the lower gabbro bark even lower.
The shape of these kicking signals can inform estimates of the structure of the oceanic crust, the researchers concluded: the readings measured from whale marks matched other scientific observations in the region.
“This approach extends the use of data that is already being collected,” says Nabelek. “It also shows that animal voices are useful not only for understanding the animals, but also for understanding their environment.”
More research will be needed to prepare this method for full use – the whale songs do not offer as high a scan as other seismic monitoring methods such as the air gun, for example, so they will not be completely instead of conventional technology. .
What they could do, however, is give scientists a closer look at the ocean crust and the seismic faults that lead to earthquakes and tsunamis. The researchers suggest that songs from other whales, such as the sperm whale, could also be used.
Further down the line, machine learning is one option to automate some of this analysis – and certainly using natural whale calls is a less aggressive and simpler approach than other approaches when it comes to to find out what ‘s going on under the ocean floor.
“The paper is a testament to a concept that could provide new avenues for using data from whale calls in research,” says Nabelek. “What we found is that whale calls may be in support of traditional passive seismic research methods.”
The research was published in Science.