Oceanographer shave long been perplexed by the fact that there is so little sediment on the floors of the world’s oceans．Their calculations，based on the estimated rate of sediment accumulation and on the time this process has had to work ，indicate that there should be a layer of sand，rock particles，and organic matter from two to two and onehalf miles thick over the bottom of the seas．Their findings of the actual thickness of the sediment layer，however，have indicated that it is not more than a fourth of this depth．（Some oceanographers believe the deposit of organic material alone，falling in what they call the “rain of death”，would have accounted for this amount of sediment．）Then in 1962the expedition scientists reported that they found the bottom of the Indian Ocean much rougher than had been though．To the oceanographers，this means that their estimates of the actual thickness of the sediment layer have been too high．
Thus it may be that an even thinner layer of sediment exists than that which oceanographers had previously considered too small．
海底的沉积物层
获得关于某一问题的新知识，并不总是能帮助科学家们解决这一问题，有时，还会使原来的问题复杂化。1962年，在报道国际印度洋远征队的考察结果时，就出现过这样明显的事例。
长期以来，对世界海洋底部的沉积物如此之少这一事实，海洋地理学家们一直感到迷惑不解。他们曾以估计的沉积物聚集速度和完成这一过程所需要的时间计算过。根据计算结果，在海底应该存在着一个2到2.5英里厚的沙、岩石微粒和有机物质层。但是，他们的调查结果却表明，这一沉积物层的实际厚度不超过这一厚度的1／4。（有些海洋地理学家认为，只要用落进他们称为“死雨”中的有机物质的沉淀，便可对这一沉积量做出解释。）
接着，远征队中的科学家们在1962年又报告说，印度洋底比人们想像的要不平坦得多。对于海洋地理学家们来说，这就意味着，他们对这沉积物层实际厚度的估计一直偏高。
因此，情况也许是这样：实际上存在着一个沉积物层，它比海洋地理学家们以前一直认为太薄的沉积物层还要薄。
The Horse Latitudes and theSpanish Adventurers
The Atlantic Ocean，named for the legendary lost island of Atlantis，has made up for the romantic origin of its name by becoming the most important commercial highway in the world；yet traces of romance continually mingle with the business of the sea．
For instance，the Spanish adventurers who first sought gold and silver in America frequently found their ships becalmed，usually on the edge of the steady trade windsabout 30degrees north or south latitude．A sailing ship could carry only so much water，and as it lay motionless under a hot sun for days or weeks，the tortures of thirst were agonizing．
The horses were generally the first victims；they had to be thrown overboard when they died or became crazed with thirst．Because the Spanish caballeros thought highly of their horses，even crediting them with souls，they suffered great remorse and believed the ghosts of the proud war horses were haunting the scene；they saw the restless spirits in their dreams and related their dreams to sailors．
Whenever the mariners passed that way，they would see in the spray or clouds images of wild horses bearing down on them；they began to call the broad belts of calm the“horse latitudes”，the romantic name by which they are known today．
回归线无风带和西班牙冒险家
大西洋是根据传说中已消失的大西岛命名的。除了其具有浪漫色彩的名字的来源外，它已成为世界上最重要的商业通道。然而，传奇故事的线索仍不断与海上贸易交织在一起。
例如，最先在美洲寻找金银的西班牙冒险家，屡屡发现他们的船只停滞不前，这通常是在稳定的信风的边缘——大约在北纬或南纬30度处。一只帆船只能装载那么多水，由于船只在烈日下数日或数周滞留原地不动，渴的煎熬使人叫苦不迭。
马匹通常是首批牺牲者。当它们渴死或渴得发狂时，人们便不得不把它们扔到船外。由于西班牙绅士们十分看重自己的马匹，甚至视之为有灵之物，所以他们深感悔疚，认为这许多他们引以为豪的战马阴魂老是在这个地点出现。他们在梦中也见到这些不安的阴魂，也把梦中所见讲给水手们听。
每当水手们经过那条水路时，总是在飞沫和浮云中看到朝他们逼近的烈马的形象。他们开始把广阔的无风带称做“马纬度”——一个现在为人们所熟知的、富有浪漫色彩的名字。
Wegener and His FloatingContinents Theory
Sabine Island，near Greeland，was first discovered and mapped by the British geographer Sir Edward Sabine in 1823，but an 1869map showed that it was actually a quarter of a mile farther west than its discoverer had indicated．This discrepancy was intriguing to Alfred Wegener，a young geologist working in Greenland in 1910．He thought the error too great to be accounted for easily．
Wegener himself took measurements and found that since 1869the island had moved an additional fiveeighths of a mile．After checking the positions of other arctic land masses，he concluded that all of them were drifting westward at different speeds．
From such data，Wegener developed his floating continents theory．He envisioned an original supercontinent that crystallized out of moltenmaterial making up the infant earth；eventually the mass cracked and broke into several pieces—the present continents．The continents do seem to fit together like pieces of a puzzle，and furthermore，some of the mountain ranges of different continents line up rather well，as if the land masses were at one time linked．
As convincing as Wegener’s argument appeared，many geologists refused to accept it，and controversy raged．Exactly how the continents were formed is still a leading geophysical mystery，though today many geophysicists are returning to the continental drift theory．
韦根纳和他的大陆漂移理论
萨宾岛，位于格陵兰附近，是英国地理学家爱德华·萨宾爵士在1823年首先发现并在地图上标出的。然而，一张1869年的地图表明：这个岛实际的位置，比发现者所标明的地点朝西1／4英里。这一差异，引起一位1910年在格陵兰工作的年轻的地理学家阿尔弗雷德·韦根纳的兴趣。他认为，误差太大，不是能轻易解释的。
韦根纳亲自测量后发现：自1869年起，该岛又移动了5／8英里。在核实了其他北极大陆块的位置后，他断定：所有这些大陆块都在以不同的速度向西移。
从这些事实出发，韦根纳提出了他的大陆漂移理论。他设想本来存在着一块超大陆，由构成新生地球的熔化物质结晶而成，最后这一陆块断裂，分成了几块——现在的洲。这些大陆看起来确实像智力测验玩具的拼块一样，能拼合在一起，而且，不同的大陆的山脉也排列有序，好像这些大陆块曾一度连在一起似的。
尽管韦根纳的论点似可令人信服，但许多地理学家还是拒绝接受它，于是争论就激化了。尽管许多地球物理学家今天又正在回到大陆的漂移理论上来，但这些大陆究竟是怎样形成的，依然是地球物理学上一个主要的谜。
