60秒科学:天然润滑油使圣安德烈亚斯断层活动不

Portions of the San Andreas fault seem to self-lubricate with a clay layer that's deposited by fluid seeping¹ through cracks opened by fault movement

The North American and Pacific plates meet in California at the San Andreas fault. The plates grind past each other there at as much as an inch-and-a-half a year. Until the plates jam. Then energy builds up, and eventually they lurch—an earthquake.

But on some active portions of the fault, the plates tend to just creep along, without many violent jerks. All thanks, it turns out, to a little mineral lube², according to a study in the journal Geology.

Geologists³ got rock cores from two miles down, at the active fault zone. They looked at those fault rocks with an electron microscope. And they found an incredibly thin coating of clay polish on the rocks.

They say that clay layer apparently⁴ lubricates the plates—like greasing ball bearings—and that it's deposited there by mineral-rich water, sucked into the fault's nooks and crannies. As the fault moves, it opens new cracks for the fluid to get into, which means more lube, and more smooth creeping. A process that’s been going on for millions of years. So given enough time, parts of the fault seem to develop their own earthquake prevention mechanism⁵. But for other sections, the clock’s still ticking
 

1 seeping   

v.（液体）渗( seep的现在分词 )；渗透；渗出；漏出

参考例句：

• Water had been slowly seeping away from the pond. 池塘里的水一直在慢慢渗漏。 来自《简明英汉词典》
• Chueh-hui could feel the cold seeping into his bones. 觉慧开始觉得寒气透过衣服浸到身上来了。 来自汉英文学 - 家（1-26） - 家（1-26）

2 lube   

n.润滑油

参考例句：

• Will you supply main engine lube oil in bulk or in barrel?你供的主机滑油是散装,还是桶装？
• Blending is the very important unit of lube oil manufacture.调和是润滑油生产工艺过程中必不可少的环节。

3 geologists   

地质学家，地质学者( geologist的名词复数 )

参考例句：

• Geologists uncovered the hidden riches. 地质学家发现了地下的宝藏。
• Geologists study the structure of the rocks. 地质学家研究岩石结构。

4 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

5 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。