These would then fall down to the base of the mantle like sparkly hailstones.

然后它们会像闪闪光的冰雹一样落到地幔的底部。

In a few minutes, rocks were falling like hailstones around them and around us.

几分钟内，石块像冰雹一样落在他们和我们身边。

And speaking of bizarre, the largest hailstone ever found measured in at roughly 20 cm, weighing almost 1 kg.

说到离奇，目前大冰雹大约20cm，重量近1公斤。

How accurate is the recreation of these hailstones?

这些冰雹的再有多准确？

Hailstones have been measured up to 20 centimeters in diameter.

据测量，冰雹的直径可达20厘米。

So the bigger the hailstone, the faster its terminal velocity.

因此冰雹越大，其终端速度越快。

Meanwhile, giant hailstones pounded the main camp.

与此同时， 大的冰雹袭击了主营地。

So this is the United States and current world record hailstone that was found in Vivian, South Dakota.

- 这是美国和目前世界纪录的冰雹，是在南达科他州维维安的。

Captain Lewis reported that the hailstones were as wide as seven inches.

刘易斯船长报告说冰雹有七英寸那么宽。

Out of the brightness of his presence clouds advanced, with hailstones and bolts of lightning.

因他面前的光辉，他的厚云行过，便有冰雹火炭。

The conditions experienced by the hailstone can change as it passes horizontally across or near an updraft.

当冰雹水平穿过或靠近上升气流时， 冰雹所经历的条件会生变化。

Hailstones also do not grow from being lofted to the top of the thunderstorm.

冰雹也不会从被放出到雷暴顶部而增长。

The layers, however, do not occur simply due to the hailstone going through up and down cycles inside a thunderstorm.

然而，冰雹层的形成并不仅仅是因为冰雹在雷暴中经历上下循环。

A laser thunder factory could shake the moisture out of clouds, perhaps preventing the formation of the giant hailstones that threaten crops.

激光雷工厂可以抖落云层中的水分，或许可以防止威胁农作物的型冰雹的形成。

Early research assumed that hailstones fell like solid ice spheres and showed very high fall speeds, even for very small hailstones.

早期研究假设冰雹像固体冰球一样下落， 并且显示出非常高的下落速度， 即使对于非常小的冰雹也是如此。

Hailstones can have layers of clear and cloudy ice if the hailstone encounters different temperature and liquid water content conditions in the thunderstorm.

如果冰雹在雷雨中遇到不同的温度和液态水含量条件， 冰雹可以有一层层清晰和浑浊的冰。

However, it is possible for very large hailstones (diameters exceeding 4-inches) to fall at over 100 mph.

但是， 非常大的冰雹（ 直径超过 4 英寸） 可能会以超过 100 mph 的速度落下。

Hailstones are formed when raindrops are carried upward by thunderstorm updrafts into extremely cold areas of the atmosphere and freeze.

当雨滴被雷暴上升气流带到大气中极冷的区域并冻结时， 就会形成冰雹。

And if the supply of water vapor is much larger, the energy released can produce stratosphere-high pillars of cloud with violent updrafts, fierce electrical storms, and grapefruit-sized hailstones.

如果水蒸气的供给足够多，所释放的能量就可以形成平流层高度的云柱，伴随着猛烈的上升气流，造成猛烈的雷暴，下起葡萄柚大小的冰雹。

Smaller hailstones can be blown away from the updraft by horizontal winds, so larger hail typically falls closer to the updraft than smaller hail.

水平风可以将较小的冰雹从上升气流中吹走，因此较大的冰雹通常比较小的冰雹更靠近上升气流。