91 Icebergs

Fog at sea is dangerous. But icebergs at sea are terrifying. Just the mention of icebergs and we immediately think Titanic. Even though that ship struck a large berg, we know icebergs can be even larger. One of the largest ever seen was in the Antarctic region. It was 60 miles wide. It was over 200 miles long. Let us compare it to one of our states. It was twice as big as the state of Connecticut. An even more important measure of size is the depth of an iceberg. For example, the Antarctic berg towered to about 400 feet above the surface of the ocean. But this was only about an eighth to a tenth of its total mass. Most of the berg—3,600 feet in this case—was under water.

How are icebergs formed? The iceberg first of all was part of a glacier or ice cap on land. The thickest ice cap of all is the Antarctic ice cap. It is 1,000 feet thick near the coast and 6,000 feet thick in the middle. The 6,000 foot portion is heavy beyond imagination. This weight in the middle puts pressure on the whole ice cap. The pressure pushes out on the ice at the ends. The ends are pushed into the sea. When these ends break off, they become floating icebergs.

Let’s shift to the North Atlantic. The bergs here break off the ice cap covering Greenland. The danger is that some of these bergs float into the routes of transatlantic liners. April, May, and June are the worst months. During these months, ships take a more southerly route.

Ships traveling at night are in special danger. After the Titanic, an ice patrol was formed to protect all ships. Ice patrols use planes and ships to locate icebergs. The patrol reports another position of all icebergs. It also charts the bergs’ probable course. No one wants another Titanic!

海上的雾很危险，但海上的冰山却很可怕。只要一提到冰山，我们立刻就会想到泰坦尼克号。尽管那艘船撞上了一座大冰山，但我们知道冰山可能更大。有记录以来最大的冰山之一出现在南极地区，它宽60英里，长超过200英里。让我们把它和我们的一个州比较一下，它的面积是康涅狄格州的两倍。一个更重要的尺寸衡量标准是冰山的吃水深度。例如，这座南极冰山在海面以上高耸约400英尺，但这只是其总质量的八分之一到十分之一。这座冰山的大部分——在这种情况下是3600英尺——都在水下。

冰山是如何形成的？冰山最初是陆地上冰川或冰盖的一部分。所有冰盖中最厚的是南极冰盖，它在海岸附近厚1000英尺，在中部厚6000英尺。6000英尺厚的部分重得超乎想象，中部的重量给整个冰盖施加了压力。这种压力将冰盖边缘的冰推向大海，当这些边缘部分断裂时，就形成了漂浮的冰山。

让我们把目光转向北大西洋。这里的冰山是从覆盖格陵兰岛的冰盖断裂而来的。危险在于，其中一些冰山会漂入跨大西洋班轮的航线。4月、5月和6月是最糟糕的月份，在这几个月里，船只走更偏南的航线。

夜间航行的船只处于特殊的危险之中。泰坦尼克号事件之后，成立了冰情巡逻队来保护所有船只。冰情巡逻队使用飞机和船只来定位冰山，巡逻队会报告所有冰山的位置，还会绘制冰山可能的航线图。没人想再经历一次泰坦尼克号的悲剧！