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[中英文稿]:
In 132 CE,
公元 132 年，
Chinese polymath Zhang Heng
中国博学家张衡
presented the Han court with his latest invention.
将他最新的发明上呈给东汉朝廷。
This large vase, he claimed,
他宣称这个大型的瓶状物
could tell them whenever an earthquake occurred in their kingdom–
可以预测国境内何时会发生地震——
including the direction they should send aid.
还会指引他们要往何处去救援。
The court was somewhat skeptical,
朝廷有点存疑，
especially when the device triggered on a seemingly quiet afternoon.
特别是当这个装置在一个 看似很宁静的午后被触动了。
But when messengers came for help days later,
但，当数日后使者前来寻求协助时，
their doubts turned to gratitude.
他们的态度从怀疑变成感激。
Today, we no longer rely on pots to identify seismic events,
现今，我们不再依靠瓶子来识别地震，
but earthquakes still offer a unique challenge to those trying to track them.
但对于试图追踪地震的人来说， 地震仍然是个很独特的挑战。
So why are earthquakes so hard to anticipate,
为什么地震这么难以预测？
and how could we get better at predicting them?
我们要如何才能预测得更好？
To answer that,
要回答这问题，我们就得了解
we need to understand some theories behind how earthquakes occur.
一些关于地震发生的理论。
Earth’s crust is made from several vast, jagged slabs of rock
地球的地壳是由数个 锯齿状的大型岩石组成，
called tectonic plates,
这些岩石叫做板块，
each riding on a hot, partially molten layer of Earth’s mantle.
每个板块都漂浮在一层 高温且部分熔化的地幔上。
This causes the plates to spread very slowly,
这会使板块缓缓散开，
at anywhere from 1 to 20 centimeters per year.
速度大约是每年 1~20 公分。
But these tiny movements are powerful enough
但这些微小的移动强大到
to cause deep cracks in the interacting plates.
足以造成相互影响的板块破裂。
And in unstable zones,
在不稳定的区域，
the intensifying pressure may ultimately trigger an earthquake.
越来越高的压力最终会触发地震。
It’s hard enough to monitor these miniscule movements,
要监视这些微小的移动 就已经够难了，
but the factors that turn shifts into seismic events are far more varied.
板块移动进而造成地震的因素 又更是多样化。
Different fault lines juxtapose different rocks–
不同的断层线让不同的岩石并列——
some of which are stronger–or weaker– under pressure.
在压力之下，有的岩石较强， 有岩石的较弱，
Diverse rocks also react differently to friction and high temperatures.
各种岩石对于磨擦 和高温的反应也不一样。
Some partially melt, and can release lubricating fluids
有些会部分熔化， 释出具滑润作用的液体，
made of superheated minerals
其成份是过热的矿物，
that reduce fault line friction.
这种液体会减少断层线的摩擦。
But some are left dry,
但有一些则是干燥的，
prone to dangerous build-ups of pressure.
当压力越来越高时就可能很危险。
And all these faults are subject to varying gravitational forces,
所有这些断层都会 受到不同重力的影响，
as well as the currents of hot rocks moving throughout Earth’s mantle.
如同热岩石在地球地幔上的 移动也会影响到断层。
So which of these hidden variables should we be analyzing,
所以，我们该分析哪些隐藏的变数？
and how do they fit into our growing prediction toolkit?
我们又该如何将它们 与发展中的预测工具相结合？
Because some of these forces occur at largely constant rates,
因为这些影响力当中， 有一些发生的频率很高，
the behavior of the plates is somewhat cyclical.
板块的行为像是具有周期性。
Today, many of our most reliable clues come from long-term forecasting,
现今，我们最可靠的线索 多半是来自长期预测，
related to when and where earthquakes have previously occurred.
我们又该如何将它们 与发展中的预测工具相结合？
At the scale of millennia,
以千年的长度来看，
this allows us to make predictions about when highly active faults,
我们就能够预测那些活跃的断层——
like the San Andreas,
像圣安地列斯断层——
are overdue for a massive earthquake.
已经超过预期的地震周期了。
But due to the many variables involved,
但因为涉及太多变数，
this method can only predict very loose timeframes.
这个方法只能预测出 很宽松的时间范围。
To predict more imminent events,
为了预测近期的地震，
researchers have investigated the vibrations Earth elicits before a quake.
研究者已经探究过在地震发生前 地球所引起的震动。
Geologists have long used seismometers
地质学家长期都在使用地震仪
to track and map these tiny shifts in the earth’s crust.
来追踪地壳中的微小移动 并将它们绘制在图上。
And today, most smartphones are also capable
现今，大部分的智慧手机都能够
of recording primary seismic waves.
记录主要的地震波。
With a network of phones around the globe,
有了全球的手机网，
scientists could potentially crowdsource a rich,
科学家就有可能以群众外包的方式，
detailed warning system that alerts people to incoming quakes.
做出有丰富细节资讯的警报系统， 来警告大家即将发生的地震。
Unfortunately, phones might not be able to provide the advance notice needed
不幸的是，手机可能 无法事先提供大家所需的
to enact safety protocols.
临震安全应变措施。
But such detailed readings would still be useful
但这些细节的读数仍然很有用，
for prediction tools like NASA’s Quakesim software,
可以用在像美国太空总署的 Quakesim 软体等预测工具上，
which can use a rigorous blend of geological data
它可以将地质资料做精确的结合，
to identify regions at risk.
来找出有风险的地区。
However, recent studies indicate
然而，近期的研究指出，
the most telling signs of a quake might be invisible to all these sensors.
这些感测器可能无法抓到 清楚的地震征兆。
In 2011,
2011 年，
just before an earthquake struck the east coast of Japan,
就在地震袭击日本东岸之前，
nearby researchers recorded surprisingly high concentrations
附近的研究者记录到 成对的放射性同位素：
of the radioactive isotope pair: radon and thoron.
氡和钍射气的浓度高得吓人。
As stress builds up in the crust right before an earthquake,
地震前随着地壳中的压力不断升高，
microfractures allow these gases to escape to the surface.
微小的破裂处让这些气体 跑到地球表面。
These scientists think that if we built a vast network of radon-thoron detectors
这些科学家认为如果我们能在 经常发生地震的区域，
in earthquake-prone areas,
建立氡—钍射气的大型侦测器网络，
it could become a promising warning system–
就可能做出理想的警告系统——
potentially predicting quakes a week in advance.
在地震发生前一周就能预测得到。
Of course, none of these technologies would be as helpful
当然，这些技术再有帮助，
as simply looking deep inside the earth itself.
都不如直接地去看地球的深处。
With a deeper view we might be able
若能看得更深，我们可能可以
to track and predict large-scale geological changes in real time,
即时追踪并预测大规模的地质变动，
possibly saving tens of thousands of lives a year.
每年可能可以拯救数万人的性命。
But for now,
但，
these technologies can help us prepare and respond quickly to areas in need–
目前这些技术 能协助我们做好准备，并针对有需求的区域做出快速应变——
without waiting for directions from a vase.
不用再等着一个瓶子来指示我们。
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