magma to rise and form new oceanic crust. A well-known example is the Mid-Atlantic Ridge, part of which is visible in Iceland. At locations like the Silfra Fissure, divers can lit- erally swim between the North American and Eurasian plates in clear, glacial water. 2. Convergent Boundaries (Subduction Zones) At these boundaries, one plate dives beneath another, often creating deep ocean trenches and volcanic island arcs. The Mariana Trench, the deepest part of the ocean, formed this way. Around subduction zones, the interaction of water and magma fuels volcanoes, contributing to formations like those in Indonesia and the Philippines – prime dive destinations. 3. Transform Boundaries These are lateral shifts, where plates slide past each other. The San Andreas Fault in California is a land-based example, but oceanic transform faults also exist and can influence the topography and biodiversity of the seafloor. The Great Tectonic Conveyor Belt, Mountains, and Valleys: Plate tectonics explains how Earth’s crust behaves like a huge conveyor belt, where it is created at spreading centers and destroyed at subduction zones. But it doesn’t just shape the seafloor – it influences life too. When Pangaea, the supercontinent, broke apart over 200 million years ago, it didn’t just form the modern oceans. It also triggered changes in climate and coastal geography that led to rapid evolution in marine life. The expanded area of continental shelves – where nutrient-rich runoff meets the open sea – created per- fect conditions for coral reefs, mangroves, and other coastal ecosystems that divers enjoy today. Mid-ocean ridges are more than just underwater curiosities. They're colossal mountain ranges stretching across the globe, making mountain ranges such as the Rockies look insignifi- cant by comparison. In the Atlantic, early oceanographers were baffled when the sea floor unexpectedly shallowed mid- ocean – what they had discovered was the Mid-Atlantic Ridge. In some places, these ridges break the ocean’s surface, forming islands like the Azores, Galapagos, and Iceland – all hotspot dive destinations. These underwater mountains are also biodiversity hotspots, acting as "stepping stones" for marine life and often hosting unique species found nowhere else. Diving in the Red Sea? Here you’ll witness a new ocean in the making. The rift between Africa and Asia is gradually widening as magma rises between them, forming new seafloor. This process is visible in the deep rift valley at the ECO PRO continued
Red Sea’s center, where new crust forms beneath divers’ fins. On land, this feature is visible in Africa’s Great Rift Valley. Over millions of years, parts of eastern Africa may sink below sea level, forming a new ocean basin – and, far off in the future, new dive sites. Hydrothermal Vents: A New Way of Life: In 1977, while exploring an area known as the East Pacific Rise off Baja California aboard the minisub Alvin , renowned oceanographer Robert Ballard made one of the most aston- ishing discoveries of the 20th century – hydrothermal vents (also called “black smokers”). Here, scientists discovered an entirely new form of life thriving in complete darkness, something previously thought to be impossible. It was soon determined these unique ecosystems were not nourished by sunlight but by chemicals such as hydrogen sulfide emitted from the Earth's crust. It turned out that hydrothermal vents were not restricted to those discovered by Ballard. Located along ocean ridges around the planet, they host unique or- ganisms, such as giant tube worms, that feed on extremophile microbes. Although most are too deep for recreational divers, their existence challenges our understanding of life and hints at what might exist elsewhere in the world – and perhaps on Dive into Dr. Alex Brylske’s Book: BENEATH THE BLUE PLANET
“An in-depth resource to indulge our passion for scuba diving.” – Wayne B. Brown, Owner & CEO, Aggressor Adventures
A fascinating look at our oceans, marine biology & more! Great for classrooms and every dive retailer’s library!
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