Get ready to go diving without the scuba equipment: New maps on Google Earth will allow virtual explorers to view parts of the deep ocean floors in far greater detail than ever before.
The bottoms of Earth's oceans contain dramatic landscapes ¬— volcanic ridges, lofty peaks, wide plains and deep valleys—but most areas remain mapped in less detail than the surfaces of the moon and Mars. The National Oceanic and Atmospheric Administration estimates that 99 percent of the seafloor remains unexplored.
"In spite of the importance of the oceans for life on Earth, the landscape beneath the sea is hidden in darkness and poorly mapped," said William Ryan, an oceanographer at Columbia University's Lamont-Doherty Earth Observatory who helped piece together the new maps. "While we can map the surface of planets from spacecraft in a single mission, to obtain comparable detail of the hidden seascape requires visiting every spot with a ship."
The new, sharper focus on parts of the seafloor — about 5 percent of the oceans — is thanks to a new synthesis of seafloor topography developed by oceanographers from scientific data. The information was collected on research cruises that traveled roughly 3 million miles across the oceans over the past two decades.
The areas now visible on Google Earth include the huge Hudson Canyon off New York City, the Wini Seamount near Hawaii, and the sharp-edged 10,000-foot-high Mendocino Ridge off the U.S Pacific Coast.
Viewers can use the "ground level view" feature of Google Earth to take them to the seafloor for a closer look at the terrain. To find which areas offer greater detail, users can download a plug-in, the Columbia Ocean Terrain Synthesis. This provides an extra layer to the conventional Google Earth imagery, showing the tracks of research cruises that have produced the higher resolution.
Virtual tours also guide "divers" through some of the highlights. Google's new 2011 Seafloor Tour takes you to some prime spots, such as the Pacific Ocean's Lamont Seamounts (named for the institution) and Mendocino Ridge, where the Juan de Fuca plate slides toward western North America, and where an earthquake could potentially unleash a massive tsunami.
A second virtual tour, Deep Sea Ridge 2000, fueled by the new synthesis and produced by Lamont-Doherty scientist Vicki Ferrini and colleagues, takes visitors to see seafloor hydrothermal vents spewing lava and hot liquids, and to learn about the creatures that thrive there.
The new data and imagery are also helping scientists understand the risks posed by some features, including earthquake zones.