章节大纲

  • Deep-sea vehicle Alvin, used for underwater exploration, including monitoring the Titanic wreck.

    In 2012, the film director James Cameron, who directed the film Titanic, made headlines when he traveled to Challenger Deep. This is the deepest known point on the ocean floor, almost 11,000 meters below the surface. Cameron was the first person to travel there alone, and he made the trip in a deep-sea diving vehicle named Deepsea Challenger. The vehicle pictured above is another deep-sea diving vehicle, named Alvin. Alvin is no longer used for ocean exploration, but by the time it was retired, it had made thousands of dives. Alvin was even used to explore the Titanic on the North Atlantic Ocean floor.
    ::2012年,导演詹姆斯·卡梅伦导演导演了电影《泰坦尼克号》,他在前往挑战者深处时成为头条新闻。这是洋底最深的已知点,在地表下将近11 000米。卡梅伦是第一个独自旅行的人,他乘坐了一部名为《深海挑战者》的深海潜水车旅行。上面拍摄的这辆车是另一辆深海潜水车,名叫阿尔文。阿尔文不再用于海洋勘探,但退休时,它已经跳了几千次。阿尔文甚至被用来探索北大西洋洋底的泰坦尼克号。

    Q : Why must divers use special diving machines such as Alvin and Deepsea Challenger to go deep below the surface of the ocean? Why can’t they just use scuba diving gear?
    ::问:为什么潜水员必须使用阿尔文和深海挑战者等特殊的潜水机器才能深入海洋表面深处? 为什么他们不能仅仅使用潜水设备呢?

    A : The pressure of the water is too great that far below the surface. It would crush divers long before they could reach the bottom.
    ::甲:水的压力太大了, 远在地表之下。 远在潜水员到达海底之前, 水就会压垮潜水员 。

    Water Pressure and Depth
    ::水压和深度

    Pressure is the amount of force acting on a given area. As you go deeper in the ocean, the pressure exerted by the water increases steadily. That’s because there is more and more water pressing down on you from above. The Figure shows how pressure changes with depth. For each additional meter below the surface, pressure increases by 10 kPa. At 30 meters below the surface, the pressure is double the pressure at the surface. At a depth greater than 500 meters, the pressure is too great for humans to withstand without special equipment to protect them. At nearly 11,000 meters below the surface, the pressure is tremendous.
    ::压力是在给定区域上演动的强度。 当您在海洋深处时, 水的压力会稳步增加。 这是因为从上面向您压压的水越来越多。 图中显示了压力如何随深度而变化。 对于地表下增加的每米, 压力会增加10千帕。 在地表下30米, 压力是表面压力的两倍。 在超过500米的深度上, 没有特殊设备, 人类承受的压力太大, 无法承受。 在地表下将近11 000米处, 压力是巨大的。

    Graph showing how water pressure increases with depth in the ocean in kPa.

    Adjusting to Changing Pressure
    ::调整到变化压力

    Scuba divers can dive without special vehicles because they don’t go very deep below the surface of the water. Nonetheless, because of the pressure of the water, scuba divers who go deeper than about 40 meters must return to the surface slowly. They must stop for several minutes at one or more points in their ascent. That’s what the divers in the Figure are doing. The stops are needed to let the pressure inside their body adjust to the decreasing pressure of the water as they swim closer to the surface. If they were to rise to the surface too quickly, the dissolved in their blood would form bubbles and cause serious health problems.
    ::斯库巴潜水员可以在没有特殊潜水器的情况下潜水,因为他们不会在水面深处潜水。 尽管如此,由于水的压力,深度超过40米的潜水员必须慢慢返回水面。 他们必须在升降点的一个或几个点停留几分钟。 图中的潜水员就是这样做的。 需要站点让体内的压力适应水压的下降,因为他们游近地表。 如果它们爬到地表太快,血液中的溶解会形成泡沫并造成严重的健康问题。

    Q : Why would dissolved gases form bubbles as pressure decreases?
    ::问题:为什么溶解气体会随着压力下降而形成泡沫?

    A : Less gas can dissolve in a fluid at lower pressure. Therefore, as pressure decreases, gases come out of solution and form bubbles.
    ::A:低气体可以在低压下溶解于液体中。因此,随着压力的降低,气体会从溶液中溶解并形成泡沫。

    Two scuba divers descending in clear water, surrounded by colorful fish and corals.

    Dive into a scuba training pool in the simulation below to learn more about oceanic pressure:
    ::潜入下面模拟的潜水训练池, 了解更多关于海洋压力的知识:

    Summary
    ::摘要

    • As you go deeper in the ocean, the pressure exerted by the water increases. For each additional meter below the surface, pressure increases by 10 kPa.
      ::在海洋深处,水的压力会增加。在地表下每增加1米,压力就会增加10千帕。
    • Water pressure makes it difficult to explore the deep ocean. The pressure is too great for divers unless they travel in pressure-resistant deep-sea vehicles. Even scuba divers have to take time to adjust to the changes in pressure as they return to the surface.
      ::水压使深海难以探索。 除非潜水员乘坐抗压的深海车辆,否则这种压力对潜水员来说太大。 即使是潜水员在返回地表时也要花时间适应压力的变化。

    Review
    ::回顾

    1. Describe how water pressure in the ocean changes as depth increases.
      ::描述海洋的水压如何随着深度的增加而变化。
    2. Why does water pressure change with depth in this way?
      ::为什么水压以这种方式随深度变化?
    3. How can divers safely travel deep below the surface of the ocean to explore the ocean floor?
      ::潜水员如何能安全地在海底深处航行,探索洋底?
    4. Why do scuba divers have to return to the surface slowly if they go deeper than 40 meters below the surface?
      ::为什么潜水潜水员必须慢慢回到表层 如果深于表层下40米深的话?