Standing on Mary’s Peak, the tallest mountain in the Oregon Coastal Range at nearly 1,250 m (4,101 ft) tall, Dr. Walter Smith looks east to the mountains and volcanoes of the Cascade range and west to the Pacific Ocean. He understands that massive forces are at work here. By examining the rocks beneath his feet, he knows that where he stands was once at the bottom of the ocean. He also knows that just to the east in the Cascades, forces within Earth occasionally unleash their fury as massive eruptions. With 17 volcanoes in this chain, there have been over 50 eruptions in the past 4,000 years.

Look at a map of the world, and pay close attention to the oceans. You’ll notice that all over the ocean floor, there are ridges that represent mountains and undersea landforms. But what about the spots that appear smooth? Does that mean that there isn’t anything there? No! Actually, it just means that this part of the ocean has not been explored yet – and we don’t know what features are there! As part of his exploration to discover what lies beneath the oceans, Walter uses satellites, like the Jason-2 satellite, to measure sea surface changes. Minute changes can reveal underwater volcanoes and mountains that help tell the story of our ever-changing Earth.

Walter has uncovered thousands of seamounts and many thousands of kilometers of new ridges and trenches. Each discovery helps to tell the story of plate tectonics. Each new feature holds the promise of much more. There may be a new and unique ecosystem waiting to be discovered or the supply to a new energy source or mineral resource that is in demand.

Mission 4 Briefing Video Prepare for your Mission by viewing this briefing on your objectives. Learn how Walter Smith discovers and analyzes the geologic features of the ocean floor which are produced by the forces from within Earth.