Only a tiny fraction of our oceans have ever been explored. As a matter of fact, we know more about the surfaces of Mars and the Moon than we do about our own ocean floor. So in honor of World Oceans Day, we collaborated with Columbia University to add more ocean seafloor terrain to Google Earth than has ever been available before. With the addition of Columbia’s Global Multi-Resolution Topography (GMRT) synthesis data, you can explore half the ocean area that has ever been mapped, an area larger than North America.

The red lines show new seafloor data from Columbia, CSUMB and UH.

Our partners at the Lamont-Doherty Earth Observatory at Columbia have curated 20 years of data from almost 500 ship cruises and 12 different institutions. See the full GMRT attribution layer in the Earth Gallery to learn more. High-res underwater mapping is vital to understanding how tsunamis will spread around the globe. For example, the National Oceanographic and Atmospheric Administration (NOAA) created a Tsunami spread map after the Japan earthquake to allow anyone to visualize the wave spread.

To get started, dive under the ocean surface by clicking any ocean in Google Earth and explore underwater volcanoes, trenches and sea mountain peaks. You can also download this Seafloor Updates kmz file to take a tour of the new high-resolution data.

Explore the Ocean Seafloor tour and others on the Ocean Showcase.

Our 2011 Seafloor Tour video highlights some of the amazing places you’ll find in Google Earth, like the Mendocino Ridge, where the massive Juan de Fuca Plate slides toward western North America.

Deep Sea Vents tour video.

Continue exploring with the Deep Sea Vents Ridge 2000 Google Earth tour, which includes the deepest volcanic eruption ever captured on video at the West Mata volcano, near Fiji. Twenty additional ocean education posts from Ridge 2000 can be found in the Explore the Ocean layer in Google Earth; download this kmz to see them all.

Complete your tour, by checking out the recently published University of Hawaii at Manoa's 50-meter seafloor synthesis for the US Hawaiian islands and California State University Monterey Bay’s new data for Cordell Bank and the Gulf of the Farallones off the west coast of California.

We hope our new high-res terrain data inspires you to dive into the unknown world that is the ocean and discover the many underwater treasures that lie beneath.

Posted by Jamie Adams, Ocean in Google Earth Team