Incredible Icebergs

Incredible Icebergs. Written by Cynthia Kennedy Hensel. Focus Question. How do icebergs affect people? How do they affect the environment?

神奇的冰山 辛西娅·肯尼迪·亨塞尔 著 思考问题 冰山会对人类产生什么影响？ 冰山会对环境产生什么影响？

Introduction For centuries, icebergs have frightened sailors in cold seas, and for good reason. When the ship Titanic made its first voyage in 1912, the ship hit an iceberg off the northeastern coast of Canada. The ship sank less than three hours later, taking about 1 ,500 people with it beneath the icy water. Icebergs rise from the ocean like mysterious white whales or snowy mountains. They are amazing to see, and yet what we see is just the small part that floats above the water's surface. That tip only hints at the massive amount of ice beneath the surface, hidden from view.

引言 几个世纪以来，冰山一直让寒冷海域的水手们心生恐惧，这不是没有道理的。 1912年泰坦尼克号首航时，在加拿大东北海岸外撞上了一座冰山。 不到三小时后轮船就沉没了，约1500人一同沉入冰冷的海底。 冰山像神秘的白鲸或是雪山一样，耸立在海面上。 它们看起来非常壮观，但我们看到的只是浮在水面上的一小部分。 露出的尖端只是暗示了水面下藏着一大片我们看不见的巨大冰体。

All about icebergs. Icebergs come from the ends of the Earth, Antarctica in the south, and the Arctic in the north. Ice sheets and glaciers there form when snow falls, then compacts over thousands of years. They move slowly downhill and break off, or calve when they reach the sea. This separation from land creates an iceberg. By definition, an iceberg is floating ice that rises at least 5 meters, 16 feet, above the sea's surface. Why does it float like that? When water freezes, it develops crystals that spread the same amount of water over a larger area. For this reason, ice is about 10 % less dense than water. It's why about 10 % of an iceberg floats above the surface.

认识冰山 冰山来自地球的两端：南边的南极洲，北边的北极。 那里的冰盖和冰川由降雪堆积，经过数千年压实后形成。 它们慢慢向下滑动，抵达海洋时就会断裂崩解。 从陆地分离后，冰山就诞生了。 根据定义，露出海面至少5米（16英尺）的浮冰才叫冰山。 冰山为什么能浮在水上呢？ 水结冰时会形成冰晶，让同等质量的水占据更大体积。 因此，冰的密度比水小大约10%。 这就是为什么只有约10%的冰山露出水面。

Many Antarctic icebergs are broad and flat like a tabletop because they break off from flat sheets of ice. Many are also huge. The largest known iceberg, B -15, was 295 kilometers, 183 miles long, and 35 kilometers, 23 miles wide. It was large enough for everyone in the world to stand on. Icebergs in the Arctic are smaller and often pointed. They travel down valleys to the sea.

南极洲的多数冰山宽大平坦，像桌面一样，因为它们从平坦的冰盖断裂而来。 许多冰山都非常巨大。 已知最大的冰山B-15，长295千米（183英里），宽35千米（23英里）。 它大到足以容下全世界的人都站在上面。 北极的冰山更小，顶端通常是尖的。 它们顺着山谷漂流入海。

Most icebergs are white because they contain air bubbles. Because the air inside is so compacted, those bubbles may hold 20 times more pressure than a car tire. When an iceberg melts, it makes a fizzing sound, like soda, as 10 ,000 -year -old air slowly escapes. Blue icebergs are made of old ice that has pressed out the air bubbles or of ice that has melted and frozen again. Green icebergs, which are rare, contain organic matter, matter from once living animals or plants, frozen into the ice.

大多数冰山是白色的，因为冰里藏着很多气泡。 由于内部空气被紧紧压实，这些气泡的压强能达到汽车轮胎的20倍。 冰山融化时，封存了一万年的空气慢慢溢出，会发出汽水一样的嘶嘶气泡声。 蓝色冰山由挤出气泡的老冰，或是融化后再次冻结的冰形成。 罕见的绿色冰山里冻着有机质，也就是曾经存活的动植物留下的物质。

Watch out! Because icebergs are so compacted, the ice found in them is much harder than ice from your freezer. It's hard enough to sink a ship, if a ship hits one. The Titanic was not the first ship sunk by an iceberg. Between 1882 and 1890, 14 ships were lost and 40 were damaged by icebergs. The loss of the Titanic, however, spurred the United States and a handful of other nations to form the International Ice Patrol, IIP, in 1912. In the North Atlantic, ice season runs from late winter through late summer. This is the period when icebergs break off from Greenland glaciers. Their journey takes several months and moves through a busy shipping area called the Grand Banks. It is the only location in the world where icebergs endanger a major shipping route.

小心！ 因为冰山被紧紧压实，它的冰比你冰箱里的冰块硬得多。 它硬到足以撞沉任何撞上它的船。 泰坦尼克号并不是第一艘被冰山撞沉的船。 1882年到1890年间，有14艘船被冰山撞沉，40艘被冰山损毁。 不过泰坦尼克号的沉没，促使美国和其他几个国家在1912年成立了国际冰情巡逻队（IIP）。 北大西洋的冰季从晚冬一直持续到晚夏。 这段时间冰山会不断从格陵兰冰川上断裂下来。 冰山要漂几个月，会经过一片叫做大浅滩的繁忙航运区。 这里是全世界唯一一处冰山会威胁主干航线的地方。