The underworld Journeys to the depths of the ocean

In her latest release, Casey immerses the reader in the science and history of deep-sea exploration. While thousands of climbers have scaled Mt. Everest, only a handful have visited the Mariana trench, the world's deepest point. Casey describes the history of underworld exploration, interviews key figures in the field, details the science of manned and unmanned submersibles, and relays her own efforts to experience the underworld via a manned submersible, all while she joins deep-sea dives around the world. The writing is engaging, and the book is loaded with lively profiles, from Victor Vescovo, a Texas businessman and explorer who funded numerous deep-sea treks, to scientists such as Don Walsh, the first person to descend to the deepest part of the ocean. While Casey's joy and awe at what has been and what waits to be discovered resonate throughout, also addressed are the significant threats facing the ocean, including the potential impacts of mining companies eager to explore its depths. Casey's thrilling account of the wonders to be found on the ocean floor will captivate readers

A fascinating account of the ocean below its twilight zone. Many scientists and adventurers have explored waters down to 600 feet, where the sunlight barely reaches, but award-winning journalist Casey, author of the bestseller Voices in the Ocean, points out that this zone, the epipelagic, "occupies only 5 percent of the ocean's volume. For all its loveliness, it's merely a ceiling. The real action takes place below." Real action is not in short supply, as the author, an oceanography enthusiast, demonstrates her journalistic professionalism, beginning with a compelling history. Clumsy exploration persuaded some 19th-century experts that the deep was lifeless, but 20th-century technical advances allowed scientists to descend to the bottom (36,000 feet at its deepest) to reveal wildly strange life forms, boiling hydrothermal vents, and volcanoes--an entire ecosystem living on chemicals and heat pouring from the center of the Earth. At these depths, there are creatures that breathe methane, fish with glasslike skeletons, and other animals that communicate through their skin. The farther down you go, "the more astonishing everything becomes." Today, dozens of deep-sea vehicles, built and operated by governments and universities as well as the occasional entrepreneur and billionaire, roam the oceans. Casey chronicles her travels around the world interviewing designers, adventurers, and scientists; she also joined some expeditions and participated in deep descents. She reminds readers that far more people have visited the International Space Station than the ocean floor, and getting down there remains more dangerous. Readers will be thrilled by the author's descriptions of truly bizarre sights and creatures as well as dazzling archaeological treasures (according to estimates, some 3 million ships linger on the seabed). Less moving is the human detritus that has reached the deepest trenches, including ubiquitous microplastics; synthetic fibers as well as industrial, chemical, and pharmaceutical waste; and bombs, live ammunition, and unneeded weapons, which the world's armies routinely dump into the sea. Space exploration gets the headlines, but Casey makes a convincing case that the deep ocean is more interesting. Copyright (c) Kirkus Reviews, used with permission.