英语听力：自然百科 神秘百慕大 bermuda triangle—7（在线收听） |
Some believe that massive underwater landslides or earthquakes can violently release gas from a substance called methane hydrate trapped beneath the sea bed. As its escaping bubbles rise, they lower the density of the surrounding ocean. The ship drops into the hole created by the gas, loads with water and eventually sinks. The density of the water is reduced. The buoyancy force reduces and therefore the ship will lie lower in the water. Potentially, even so low that it will sink.
Keep an eye * and on the corner.
A team at the University of Michigan tests this theory.
If there is a ship out there in bubbles due come up, what's it gonna do to the stability to the ship and will the ship sink?
The marine engineers prepare their 1 to 50 scale model of the U.S.S Cyclops. It's not everyday that a hydrodynamic lab gets to sink a model, so we'll pretty pump up about this. We normally try to keep the miles on the surface.
Tim moves the 'Cyclops' into a 360-foot long water tank for its maiden voyage.
OK. Clear.
The team places weights in the model's hull to replicate how the 2,000 ton collier would sink in the water. The 'Cyclops' is then placed over a pipe with holes. Compressed air will be force through these holes into the water above, creating a stream of large underwater bubbles. Will the 'Cyclops' survive?
Along the sea floor of the Bermuda Triangle lie massive deposited methane hydrate gas. This experiment replicates what would happen if huge amounts of this gas were violently released. A model of the U.S.S Cyclops is hit by a barrage of bubbles. If scale to life size, this would be roughly 40 feet wide.
What we saw was the bubbles came up below the model. The model almost dropped a little bit because the loss of buoyancy and the water erupted around the side of the model. And that created a situation where the water rushed into the hull. |
| 原文地址：http://www.tingroom.com/lesson/zrbaike/2010/259132.html |