Scripps Institution of Oceanography has contributed seafloor imagery to a newly released version of popular virtual-map program Google Earth. In addition to providing Google with a 3-D backdrop of the ocean, Scripps has also contributed highlights from the two-year voyage of research vessel Melville to be included in an ‘Expedition Layer’ for users to explore.
David Sandwell, professor of geophysics at Scripps Institution of Oceanography, provided bathymetric data ‘mdash; measurements of ocean depth ‘mdash; for the project, with assistance from Walter Smith of the National Oceanic and Atmospheric Administration.
‘The good side of the map is that it is global ‘mdash; we provided a pixel for everywhere in the oceans ‘mdash; but the bad side is that it’s not as high resolution as more local maps,’ Sandwell said.
Sandwell and Smith have been researching bathymetry techniques for nearly 20 years in an effort to provide a clearer image of the ocean floor. Various methods exist to carry out the mapping process, the most time-consuming being the bouncing of sound waves off the ocean floor to measure depths. Only 10 percent of the seafloor has been mapped using this method.
To fill in missing data, alternative techniques are employed.
‘A typical [gap] is about the size of New Jersey, so we use measurements in the variation of gravity,’ Sandwell said.
Smith adds that by using satellites, various features of the ocean floor can be detected.
‘These [satellites] see the ocean surface tilted over mountains on the ocean floor because they have a gravitational pull that adds to and changes the overall pull of the earth, which changes the sea level,’ Smith said.
Steve Miller, product manager for Google Earth, began work on the program’s ocean layer as a side project and hopes the new version will prove beneficial to the general public and scientists alike.
‘I think we have a particular interest in the general public because we have such a wide range of people that use Google Earth, and we’re excited to have scientists and people doing active research be able to share what they do with the world,’ Miller said.
Smith emphasized the program’s accessiblity and easy-to-use features.
‘We are delighted to have this new tool because it can put information about the ocean and the ability to explore the oceans in front of [millions] of people,’ Smith said.
Google approached several institutions for additional marine data, including the General Bathymetric Chart of the Oceans and the Naval Oceanographic Office.
‘We put together a group of people we could have as advisers, and Scripps was a natural fit for that,’ Miller said. ‘Because of its reputation we thought it would be a good place to talk to a lot of scientists and find out how this tool could be useful for them.’ According to Smith, some of the data was provided to Google by associations based outside the U.S.
‘We were able to get data from countries that don’t officially cooperate with the United States but will send the data to an international effort,’ Smith said.
The ‘Expedition Layer” details various journey milestones of the Melville, which departed from San Diego in 2006 and stopped in 17 ports and 10 countries ‘shy;’mdash; including Japan, Fiji and Taiwan ‘mdash; to conduct 49 separate research missions.
Readers can contact Omair Qazi at [email protected].