To get a glimpse of what’s happening in the deep blue, a team of scientists deployed thick, glass spheres anchored by barbell plates in four spots at the bottom of the Argentine Basin, off the coast of Uruguay. The instruments continuously collected data on the seafloor by logging measurements every hour from 2009 to 2019.
Their study, published last month in the journal Geophysical Research Letters, revealed that at 4,757 feet underwater—nearly three miles down—temperatures increased from 0.232 degrees Celsius to 0.248 degrees Celsius. In comparison, land and ocean surface temperatures in 2019 were 0.95 degrees Celsius higher than the long-term average.
The ocean’s temperature changes may seem slight, but they’re definitely not, Meinen says.
“If you think about how large the deep ocean is, it’s an enormous amount of heat,” he tells The Guardian. Plus, warm water rises, so it would take some serious heat to trigger even the slightest increase in temperature, Meinen tells Science News.
“We didn’t expect that you would see hour-to-hour and day-to-day variations down that deep,” he tells The Guardian. “There are processes in the deep ocean that are making things change rapidly, and we don’t really know what those processes are yet.”
The ocean plays a crucial role in regulating earth’s climate since it absorbs an estimated 90 percent of the planet’s heat. But as it absorbs more heat and gradually warms, the water molecules expand, leading to rising sea levels and more intense hurricanes.
https://www.smithsonianmag.com/smart-news/deepest-darkest-most-frigid-depths-ocean-are-warming-new-study-shows-180976126/