S9-U6L2 Part 3

More than two kilometers below the ocean surface, scorching water jets out of the seafloor along the mid-ocean ridge. A rich ecosystem of bacteria, tubeworms, crabs, and a variety of other organisms survive on the warmth and chemicals provided by these hot springs. Exploring the submarine hot springs is challenging. Scientists and engineers have had to design vehicles that can travel deep underwater and navigate through rugged terrain without sunlight. They have had to build equipment to withstand the extreme pressure from the water above as well as the temperatures ranging from 4 °C to greater than 350 °C. 

People use Earth’s magnetic field for navigation using compass needles, which point toward Earth’s magnetic poles. Scientists have discovered that many other organisms—including certain types of birds, bats, fish, worms, and bacteria—also navigate or orient themselves using Earth’s magnetic field. The ability to sense a magnetic field is known as magnetoreception. Since the strength and direction of the magnetic field depends on location, organisms with magnetoreception can use it to orient themselves.

People have tried to explain natural events such as earthquakes and volcanic eruptions for thousands of years. Many of these explanations are in the form of myths and legends, or folklore. Native Hawaiians, for example, believed that volcanic eruptions were caused by Pele, the goddess of fire, lightning, dance, wind, and volcanoes. People in Siberia told a story of a god named Tuli, who drove a dogsled over Earth. When the dogs stopped to scratch fleas, the ground would shake.