Indian Ocean warming up at unprecedented rate: Here’s how scientists use earthquake data to monitor this change

Oceans are warming up as they hold the 95 per cent of the heat trapped on Earth due to the emission of greenhouse gases like carbon dioxide. Indian Ocean is also impacted by the phenomenon and the rate at which the heating up of the ocean has risen significantly. A 3000-kilometer-long section in the equatorial East Indian Ocean recorded fluctuations in temperature, and the fluctuations between the years 2005 and 2016 show a trend that the warming has exceeded the estimates substantially. Scientists at the California Institute of Technology (Caltech) in the US have come up with a way to map the change in temperature of the ocean. According to the scientists, analysing the sound from seabed earthquakes can help determine the rate at which the Indian Ocean is warming up, news agency PTI reported.

The study highlighted that for studying the earthquakes, they will monitor underwater quake sounds. It is to note that the underwater earthquake sounds are powerful and the quake waves possess the capability to travel long distances as they do not weaken easily. According to the report, whenever an earthquake takes place under the ocean, the energy travels through the earth. However, there is a portion of this energy which is transmitted into the water in the form of sound. Similar to seismic waves, the sound waves also “propagate outward from the quake’s epicenter,” the report said. But the speed of sound waves is much slower when compared to seismic waves. Now the question is how will the sound waves help determine change in temperature of Indian Ocean.

The temperature of water impacts the speed of sound waves in water. With increased temperature of water, the speed of sound waves will also increase. This will allow scientists to study the rise in water’s temperature. Further, “the earthquakes which happen repeatedly in the same place” will provide more information of the warming of ocean water, the report noted.

This method will give the scientists a relatively low-cost technique to monitor water temperature in oceans across the globe. Meanwhile, one estimate has indicated that the Indian Ocean has been warming up 70 per cent more than what had been believed but it cannot be drawn as an immediate conclusion. For more certainty on the rate of change in ocean temperature, more studies and analysis will be needed.