Between the surface of the sea and the ocean floor lays a largely unexplored realm. Scientists estimate that humans have investigated only 1 percent of the deep sea.Only recently have submersibles (research submarines) been capable of making the journey down to oceans' extreme depths.Even with this new technology, deep-sea biologists and geologists risk their lives as they descend miles below the water's surface, plunging into the unknown depths below.
ThriftBooks sells millions of used books at the lowest everyday prices. We personally assess every book's quality and offer rare, out-of-print treasures. We deliver the joy of reading in recyclable packaging with free standard shipping on US orders over $15. ThriftBooks.com. Read more. Spend less.