Dive and Discover : Exp. 8 : Juan de Fuca Ridge : Mail Buoy

Juan de Fuca Ridge
Expedition 8:
May 24-Jun 10, 2004

Mail Buoy
May 27, 2004

My 7th/8th grade Oceanography students have recently been introduced to bathymetric maps. How has the mapping technology changed in the last 10-20 years?

Kathleen Heidenreich
Chinook Middle School, Lacey Washington

Chief scientist Debbie Kelley responds:

Hi Kathleen and class:

Our ability to map the seafloor has dramatically improved during the past 10 to 20 years. Development of new satellite systems, such as the Global Positioning System (GPS), has provided very accurate information about where we are in the world’s ocean. Computers on board the ship “talk” to this array of satellites, and they tell us where we are within meters. This, coupled with advanced sonar systems that are mounted on the hulls of the ships, provide maps of the seafloor that show the topography at scales of less than 100 feet to 100’s of feet.

However, oceanography is in an incredibly exciting period of instrument development that is allowing us to do new kinds of science and ask questions we have never been able to ask before. New autonomous vehicles, such as the Autonomous Benthic Explorer (ABE), host advanced sonar systems that allow us to map the seafloor at the scale of an individual black smoker chimney. These vehicles are programmed to “swim” freely within the ocean and map out sections of seafloor using surveys that look like the tracks you make when you mow your lawn.

The vehicles contain very smart computers that allow the robotic vehicles to fly above the hills and valleys along the seafloor, mapping as they go. They are extremely valuable tools to explore areas of the ocean that we have never been to before. Some also host sensors that provide information about where hydrothermal plumes are at the same time they are making maps of the seafloor. In this way we get a map of where the chimneys or volcanoes are and indications of whether they are active or not.

We are very excited about these new vehicles because we have much to learn about the seafloor, which covers more than 70% of our planet. The surface of Mars is mapped better than the planet that we live on, so there are many opportunities for new discoveries to be made about the deep sea and the surprises that it hides beneath its surface.

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