地球上所有的水
(原标题: All the Water on Planet Earth)
2022-09-26
浏览次数: 17
地球上有多少是由水构成的？实际上很少。虽然海洋覆盖了地球表面的70%，但与地球的半径相比，这些海洋是浅的。这幅特色插图展示了如果地球表面上或附近的所有水都聚集成一个球将会发生什么。这个球的半径只有大约700公里，不到月球半径的一半，但比土星的卫星土卫五略大，土卫五和我们太阳系外的许多卫星一样，主要是水冰。第二个最小的球描绘了地球上所有的液态淡水，而最小的球显示了地球上所有淡水湖和河流的体积。这些水是如何来到地球上的，以及是否有大量的水被困在地球表面以下，仍然是研究的主题。
查看原文解释
How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius. The featured illustration shows what would happen if all of the water on or near the surface of the Earth were bunched up into a ball. The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth's Moon, but slightly larger than Saturn's moon Rhea which, like many moons in our outer Solar System, is mostly water ice. The next smallest ball depicts all of Earth's liquid fresh water, while the tiniest ball shows the volume of all of Earth's fresh-water lakes and rivers. How any of this water came to be on the Earth and whether any significant amount is trapped far beneath Earth's surface remain topics of research.