Book Recommendation

The Underworld: Journeys to the Depths of the Ocean by Susan Casey

The Underworld: Journeys to the Depths of the Ocean, by best-selling science journalist Susan Casey, is shockingly fascinating. Much of it is so unlikely as to seem completely fictional.

Just about everything in this book was unknown to me, from the depth of the ocean (in its deepest part, close to 36,000 feet deep) to the range of organisms and creatures to the geological features to the submersibles and robots used in ocean exploration. Ever heard of black smokers? These are chimney-like structures that pump sooty fluid “like a manic locomotive…a vortex of black clouds, lined with metal crystals,” or the Lost City, whose chemistry makes it “a frontrunner in the search for life’s origins”? Casey also focuses on the fascinating cast of characters who are driven to discover this underground world, the technical challenges, and the overarching reason that learning about the deep ocean is so important—the very future of the planet depends upon it. There is an extraordinary number and diversity of marine organisms invisible to the eye that have an enormous role in keeping the planet alive. Since 1970 the ocean has absorbed 93% of the excess heat and 30% of the carbon dioxide we’ve generated from burning fossil fuels. The ocean is now becoming warmer, more acidic, and less oxygen rich, and our ecological balance is in peril. There is also the enormous risk of destroying the seafloor from indiscriminate deep-sea mining by commercial interests. Although the book is a call to action and a justification of the time, expense, and risk in exploring the deepest of the deep, Casey’s descriptive writing is exuberant and joyful. “A spectral figure materialized from the darkness, gliding toward the bait. … It was an apparition, a phantom, a psilocybin vision…it resembled a gelatinous dog’s head trailing a white tendril. The head was luminous and as crystalline as a bubble. It glimmered in pale shades of violet and topaz, with twinkles of aquamarine and white, and there were glowing orbs suspended inside it, like the electrodes of a cyborg brain dreamed up by Ridley Scott.” Wow!

The book is a tribute to deep sea exploration for affording us a way to understand our role in the universe as well as a meditation on the ecstasy one feels when being “in the middle of the life force itself.” On one journey into the deep that Casey is able to take, she reflects, “In the abyss, you don’t glimpse the mystery—you enter it—and your consciousness is the only fixed point.” Pretty powerful stuff.