Table of Contents The Ocean is the Last Frontier 4 The Ocean Is Full of Extremes Research Ships Are Floating Laboratories 8 Submersibles Go Deeper Than Ever 10 Divers Can Explore Shallow Depths 12 Observation Systems Monitor the Oceans 14 16 Strange Creatures Live in the Deep Ocean Shipwrecks Litter the Deep 18 Underwater Volcanoes Change Earth's Surface 20 Underwater Cities the Past and Our Future 22 Ocean currents Are a Possible Energy Source 24 The SeaOrbiter is an Oceangoing spaceship 26 Fact Sheet 28 Glossary 30 For More Information 31 Index 32 About the
The Ocean is the Last Frontier For thousands of years people have how deep it was This distance was sailed Earth's oceans But what lies about six feet 1 8 m and is still below the surface has long remained used today It is called a fathom a mystery Ancient Viking sailors The weights also brought up took the first steps to finding out in samples of the soft dirt from the the 700s They dropped weights off ocean bottom The Viking sailors a long line of ships into the ocean had no way to analyze these Then they pulled them back up and samples used the arm span of a sailor to see The Vikings were the first known people to explore below the ocean's surface OOOOOOOOCEO
MAPPING THE OCEAN FLOOR Thickness in inches 13 cm of the metal walls of the Trieste needed to withstand the pressure of the Challenger Deep Earth's oceans are wide deep and hard to map There are maps of the ocean floor but not in great detail Only objects in the ocean larger than 3 1 miles 5 km are completely mapped There are planets that have more detailed maps Mars has been mapped to within 328 feet 100 m The Vikings were the first to try to measure the ocean depth They brought up samples of soft dirt from the ocean floor The HMS Challenger made an important ocean exploration voyage the 1870s In 1960 humans visited Challenger Deep the deepest point on Earth But it was an early clue into what is beneath the waves Those depths remained a mystery for many years In the 1870s a ship called the HMS Challenger made the first significant bottom of the ocean The Trieste took two people to challenger Deep exploration of the seafloor The ship traveled nearly 70 000 miles 113 000 km around the world Its crew mapped underwater features using a similar method to the Vikings They also discovered new species of life that they brought on in the Mariana Trench 35 810 feet 10 915 m below the surface of the Pacific Ocean board The ocean covers most of Earth But there is still a lot we do not know It was not until the 1930s that about it As technology advances humans got to actually see the scientists are finding out more about ocean floor New submarines were oceans every day able to dive thousands of feet In 1960 humans visited the very
