Explore the Deep Sea
Expedition 1: Seafloor Mapping
Sailing on the University of Hawaii's research ship, the Research Vessel Kilo Moana, this expedition was led by Chief Scientist Fernando Martinez (left). The start of the expedition was nearly delayed by an intense storm, but despite this setback, the team of 24 scientists and 20 crew members spent a productive four weeks at sea (April 2004).
Maps help target future sites
The first major aim of the expedition was to map the seafloor in the Lau Basin, producing an overall map, plus detailed maps of certain areas. These maps were successfully produced using sonar equipment, and they are now being used in two main ways:
- To help decide where future expeditions should concentrate efforts.
- To help understand more about the geology of the area. For instance, by comparing these maps with previous maps, recent lava flows and other volcanic activity can be identified. By looking at seismic cross-sections deep into the seafloor, more can be understood about how the Earth's crust is being deformed in this sort of ocean basin.
Tracking deep-ocean currents
The second major aim of this April 2004 expedition was to launch several "floats"—pieces of equipment that are carried along by ocean currents. The floats are programmed to sink to a certain depth for a defined length of time, then return to the surface and broadcast their position. After several hours broadcasting, they sink again. By tracking the signals from the floats using satellites, researchers can work out how fast, and in what direction, the currents are moving. This information is very useful when trying to work out answers to questions such as:
- How do compounds expelled from deep-sea volcanoes and vents affect the chemical composition of the ocean? (for instance, this information may help us better predict how the oceans will respond to climate change)
- How do creatures found around deep-sea vents disperse to other suitable sites?
The floats are expected to keep sending information to the satellites for several years.
» Mmore about tracking deep-ocean currents in the Lau Basin, from researchers at Lamont-Doherty Earth Observatory.