29 No Laughing Matter

Never laugh at a snow-covered mountain! Laughter and yelling during the avalanche season can trigger a deadly pile of snow. Huge snow slides are most common in mountains where there are steep slopes that are well buried in snow and ice. The snow builds up slowly and lands very softly. This can create a very touchy, unstable situation. Tons of snow may be held up by only the friction between snowflakes. The slightest movement can cause it to tumble. As soon as something slips, a great mass of snow will come crashing down the mountainside.

Slides may be started by sound vibrations. They may also be started by the weight of wet, melting snow. Once an avalanche has been triggered, the cause no longer matters. Moving down a steep slope, it picks up great speed and added snow. Some avalanches travel as fast as 200 miles per hour. The force of an avalanche will snow down anything in its path. Whole houses have been swallowed up by these fast-paced piles of snow.

The wind that is caused by an avalanche is almost as destructive as the snow itself. Winds from an avalanche have been known to travel as fast as those of a tor- nado. So, when approaching a thickly snow-covered mountain, speak softly!

29 绝非儿戏

绝不要嘲笑被雪覆盖的山！在雪崩季节大笑和大喊可能会引发致命的雪堆。巨大的雪崩在有陡峭山坡且被冰雪厚厚覆盖的山区最为常见。雪慢慢堆积，轻柔地落在地上，这会造成一种非常敏感、不稳定的状况。成吨的雪可能仅靠雪花之间的摩擦力支撑着，最轻微的移动都可能导致它崩塌。一旦有东西滑落，大量的雪就会沿着山坡轰然坠落。

雪崩可能由声音振动引发，也可能由潮湿、融化的雪的重量引发。一旦雪崩被触发，起因就不再重要了。它沿着陡峭的山坡向下移动，速度越来越快，还会裹挟更多的雪。有些雪崩的移动速度可达每小时200英里。雪崩的力量会将沿途的一切都淹没在雪中，整座房屋都被这些快速移动的雪堆吞噬过。

由雪崩引发的风几乎和雪本身一样具有破坏性。众所周知，雪崩产生的风速度能和龙卷风的速度一样快。所以，当靠近一座被厚雪覆盖的山时，要轻声说话！