8 Tides

Tides written by Pam Holden

Pam Holden写的潮汐

Tides are the rise and fall of the sea. Changes in the tide happen along the coasts and in rivers near the sea. High tide is when the water is deeper and comes up high on the shore. Low tide is when the water is shallower and does not come up so far. Tides change because the moon and the sun pull on the oceans and make them rise. The moon pulls more strongly than the sun because it is closer to Earth. High tides happen as the sea rises, and low tides happen as it falls. Most places have two high tides and two low tides every day.

潮汐是大海的涨落。 潮汐的变化发生在沿海地区和靠近大海的河流中。 高潮是指海水变深，涨到岸上的高度。 低潮是指海水较浅，不会涨得那么高。 潮汐的变化是因为月亮和太阳对海洋的引力使它们上升。 月球的引力比太阳更强，因为它离地球更近。 涨潮发生在海平面上升的时候，退潮发生在海平面下降的时候。 大多数地方每天有两次涨潮和两次退潮。

Each month there are two special tides called spring tides. The name has nothing to do with the season spring, but is because the sea rises higher. Spring tides happen when the moon and the sun are in line with Earth and they pull together. Spring tides have a big difference between high tides and low tides— high tides are extra high and low tides are very low.

每个月有两次特殊的潮汐，叫做春潮。 这个名字与春天的季节无关，而是因为海平面上升得更高。 当月亮和太阳与地球在一条直线上时，大潮就会发生。 春潮的涨潮和退潮有很大的不同——涨潮很高，而退潮很低。

There are also two tides each month called neap tides, which are the opposite to high tides. Neap tides happen when the moon and the sun are in two different directions and they do not pull together. Neap tides do not rise and fall very much, so they have only a small difference between high tides and low tides.

每个月还有两次潮汐叫做小潮，与高潮相反。 小潮发生时，月亮和太阳在两个不同的方向，他们不拉在一起。 小潮涨落不大，所以涨潮和退潮之间只有很小的差别。

Sometimes strong winds and storms make tides come up much higher than usual. Sea walls have been built to stop damage from huge waves. Some rivers near coasts have special barriers to stop tidal waves from flowing up the rivers into cities and towns.

有时强风和风暴使潮汐比平时高得多。 建造海堤是为了防止巨浪的破坏。 一些靠近海岸的河流有特殊的屏障来阻止潮汐波顺着河流流入城镇。

Tides are important to people for work and play. Tide times are about an hour later each day, so there are charts to tell when high and low tides will happen. Fishermen need to know the best times to move their boats and to catch fish. Big ships need to move in and out of ports and bays at high tide, when the water is deeper. For swimmers, it is safer when the water is flowing in than when the tide is pulling out. Surfers get a better ride as big waves push them in to shore.

潮汐对人们的工作和娱乐都很重要。 每天的涨潮时间大约晚一个小时，所以有图表可以告诉我们涨潮和退潮的时间。 渔民需要知道移动船只和捕鱼的最佳时机。 大型船只需要在涨潮时进出港口和海湾，此时海水较深。 对于游泳者来说，水流入时比退潮时更安全。 当巨浪把冲浪者推向岸边时，冲浪者可以更好地冲浪。