Three Waves

Wave Oil

Engineers are looking into producing power from everyday ocean waves.

"Harnessing only 10 or 15 percent of the incoming waves… you would produce the same amount of electricity as all of the dams, the conventional hydroelectric dams, throughout the U.S…. with fairly small environmental impact," says oceanographer and ocean engineer George Hagerman. That's enough energy to power about 30 million homes each year.

Capturing 1 to 2 percent of global wave power, could supply 13 percent of the world's current demand for electricity.

As part of a study managed by the Electric Power Research Institute (EPRI), Hagerman, from Virginia Tech's Advanced Research Institute, found that wave power is a practical alternative to our shrinking supply of fossil fuels.

There are three different categories of classifying wave energy devices and they're different in how they interact with the wave. There are moored buoy systems, such as the AquaBuOY, which heave up and down in the waves, converting the vertical energy of the wave into power that is transmitted to shore by means of an undersea power line. Another device known as the "Wave Dragon" is what they call a terminator. "Terminator devices basically intercept the wave and they don't let any wave energy go behind them, or very little energy go behind them," he explains. The Wave Dragon has a ramp for waves to surge up and, "spill water into the container. They create a higher level of water in the container than in the surrounding ocean, so that it can drain back through a hydroelectric turbine and generate power." The Scottish company Ocean Power Delivery developed a snake-like device called the Pelamis, which absorbs energy from its bending hinges as waves pitch it up and down. "The Pelamis looks a bit like a broken pencil floating on the sea surface," Hagerman says. "It would orient itself — it would weathervane — so, as the waves flow along the device, energy is pulled out of the waves by the relative pitching of this broken pencil." The Pelamis falls into a group of wave power devices called attenuators. Ocean Power engineers say that 40 of their sea snakes spread across 250 acres would supply enough electricity to feed as many as 20,000 households. The design allows Pelamis to withstand storm waves that rise 10 times as high as average waves and pack a hundred times as much power.

Discover Magazine, December 2005, Vol 26, No 12, Pg 42-45, and Sciencentral

A New Ocean

For the first time in recorded history, humans are witnessing the birth of a new ocean. In September, an earthquake struck in the Afar desert of Ethiopia, leaving a narrow, 37 mile long crack in the earth. Over the course of three weeks, it widened to form a 13 foot wide chasm. Using instruments to measure seismic activity, geologists have concluded that the crack will expand by about .8 inches a year, eventually breaking off eastern Ethiopia from the rest of Africa and filling with water. The crust under the Afar desert is changing to resemble the crest beneath the Red Sea, geologists say. When the basin fills in, about a million years from now, water will migrate from the Red Sea and the Gulf of Aden. "We believe we have seen the birth of the new ocean basin," researcher Dereje Ayalew tells the Associated Press. "This is unprecedented in scientific history, because we usually see the split after it has happened. But here we are watching the phenomenon."

The Week Magazine, Jan 13, 2006, Vol 6, Iss 241, pg 19

Ears that Breathe

By examining fossils from a prehistoric fish, two Swedish scientists have concluded that our ears evolve from an organ once used for breathing. The fish, Panderichthys, was a precursor to the first tetrapod, the animal that crawled onto land and eventually spawned all four legged vertebrates, including humans. A bottom dweller, Panderichthys had a spiracle, a tube for breathing water through the top of its head while its face was buried in the mud. From this spiracle's anatomy and its position in the head relative to the fish's usually short jaw bone, a known ancestor of the modern ear's stirrup, scientists deduced that it was a precursor to a fully developed middle ear.

The Week Magazine, Feb 10, 2006, Vol 6, Iss 245, pg 19