Google diving into 3D mapping of oceans

We've got Google Earth and Google Sky. Next up will be a map of the world below sea level — Google Ocean.

The company has assembled an advisory group of oceanography experts and in December invited researchers from institutions around the world to the Mountain View, Calif., Googleplex. There, they discussed plans for creating a 3D oceanographic map, according to sources familiar with the matter.

The tool — for now called Google Ocean, the sources say, though that name could change — is expected to be similar to other 3D online mapping applications. People will be able to see the underwater topography, called bathymetry; search for particular spots or attractions; and navigate through the digital environment by zooming and panning. (The tool, however, is not to be confused with the "Google Ocean" project by France-based Magic Instinct Software that uses Google Earth as a visualization tool for marine data.)

Asked to comment on Google Ocean, a Google spokeswoman said the company had "nothing to announce right now."

Oceanography researchers, however, say such a tool would be incredibly useful.

"There is no real terrain or depth model for the ocean in Google Earth," said Tim Haverland, a geospatial application developer at the Fisheries Service of the National Oceanic and Atmospheric Administration (NOAA). "You can't get in a submarine and in essence fly through the water and explore ocean canyons yet."

Google Ocean will feature a basic layer that shows the depth of the sea floor and will serve as a spatial framework for additional data, sources said, adding that Google plans to try to fill in some areas of the map with high-resolution images for more detail.

Additional data will be displayed as overlying layers that depict phenomena like weather patterns, currents, temperatures, shipwrecks, coral reefs and algae blooms, much like the National Park Service and NASA provide additional data for Google Earth and Google Sky.

"Google will basically just provide the field and then everyone will come flocking to it," predicted Stephen P. Miller, head of the Geological Data Center at the Scripps Institution of Oceanography. "There will be peer pressure to encourage people to get their data out there."

This is an image of a bathymetry map that shows the depth of the sea floor. It is based on sparse ship soundings and satellite altimeter measurements of subtle bumps and dips in the ocean surface which are produced by tiny variations in the pull of gravity. (Credit: David Sandwell and Walter Smith/Scripps Institute of Oceanography)

While satellite imagery has the entire globe covered, as well as a good amount of known outer space, much less is known about the bodies of water that cover about 70 percent of the planet. Only a small percentage of the sea floor has been mapped in detail by sonar.

"It would take about 100 ship years to map the oceans at high resolution," said Dave Sandwell, a professor of geophysics at the Scripps Institution of Oceanography.

Sandwell speculated that Google will get at least some of the basic sea floor data from Scripps' Predicted Depth Map. Created from ship sonar soundings and satellites, it infers the depth of the sea floor based on the tiny bumps and dips in the ocean's surface.

To bring more clarity to the sea floor, Sandwell and others said, Google will likely use high-resolution grids from oceanographic institutions showing the depths of select areas of the seas and paste them in. Data for those grids, which cover a very small portion of the sea floor, are created by ships using multibeam sonar.

One possible source for Google Ocean data are detailed "tiles" from multibeam and predicted topography compiled by the Lamont-Doherty Earth Observatory (LDEO) of Columbia University. Tiles are high-resolution sun-shaded images as well as digital elevation models covering the entire global ocean that allow for interactivity similar to Google Earth, where you can get different views by zooming in and out and by tilting the planet's surface.

This screenshot shows an example of high-resolution imagery above and below sea level. The view is looking eastward at Monterey Bay on the California coast with the Sierra Nevada Mountains in the background. The continental slope is sculpted by submarine canyons with their numerous tributary gullies. (Credit: GeoMapAppVG/Lamont-Doherty Earth Observatory of Columbia University)

"Our application gets data from databases over the Internet without the user having to know the name of the database or how to connect to it. Google could talk to our databases," said William B. F. Ryan, an earth and environmental studies professor at Columbia's LDEO.

Ryan cautioned that "Google would have to put the tiles on their servers because their public of millions would bring the servers at Columbia University to their knees."

On top of the depth map, and in addition to the select high-resolution tiled areas, there will likely be various layers of specialised data from different sources. For example, NOAA already has made public visual information for Google Earth related to sea hotspots around coral reefs, Gulf of Mexico marine debris, surface temperatures and wave heights in the Great Lakes and shipwrecks.

In addition to the "wow factor" Google Ocean will no doubt have for amateur oceanographers, marine enthusiasts and anyone fascinated by the movie 20,000 Leagues Under the Sea, the project has the potential to promote more collaboration and advance research.

"We hope that one of the outcomes of Google Ocean will be an understanding of how much remains to be explored," said Miller of Scripps. "We know far more about the surface of Mars from a few weeks of radar surveying in orbit than we know of the bottom of the ocean after two centuries."