[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In 132 CE,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Chinese polymath Zhang Heng
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,presented the Han court with \Nhis latest invention.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This large vase, he claimed,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,could tell them whenever an earthquake \Noccurred in their kingdom–
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,including the direction \Nthey should send aid.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,The court was somewhat skeptical,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,especially when the device triggered \Non a seemingly quiet afternoon.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But when messengers came \Nfor help days later,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,their doubts turned to gratitude.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Today, we no longer rely on pots to \Nidentify seismic events,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but earthquakes still offer a unique\Nchallenge to those trying to track them.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So why are earthquakes so \Nhard to anticipate,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and how could we get better \Nat predicting them?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,To answer that,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,we need to understand some theories \Nbehind how earthquakes occur.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Earth’s crust is made from several vast, \Njagged slabs of rock
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,called tectonic plates,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,each riding on a hot, partially molten\Nlayer of Earth’s mantle.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,This causes the plates to \Nspread very slowly,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,at anywhere from 1 to 20 \Ncentimeters per year.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But these tiny movements are powerful \Nenough
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to cause deep cracks in the\Ninteracting plates.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And in unstable zones,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the intensifying pressure may \Nultimately trigger an earthquake.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,It’s hard enough to monitor these \Nminiscule movements,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,but the factors that turn shifts into \Nseismic events are far more varied.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Different fault lines juxtapose \Ndifferent rocks–
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,some of which are stronger–or weaker–\Nunder pressure.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Diverse rocks also react differently to\Nfriction and high temperatures.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Some partially melt, and can release\Nlubricating fluids
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,made of superheated minerals
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,that reduce fault line friction.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But some are left dry,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,prone to dangerous build-ups of pressure.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And all these faults are subject to \Nvarying gravitational forces,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,as well as the currents of hot rocks\Nmoving throughout Earth’s mantle.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,So which of these hidden variables \Nshould we be analyzing,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,and how do they fit into our \Ngrowing prediction toolkit?
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Because some of these forces occur \Nat largely constant rates,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the behavior of the plates \Nis somewhat cyclical.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Today, many of our most reliable clues \Ncome from long-term forecasting,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,related to when and where earthquakes \Nhave previously occurred.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,At the scale of millennia,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,this allows us to make predictions \Nabout when highly active faults,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,like the San Andreas,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,are overdue for a massive earthquake.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But due to the many variables involved,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,this method can only predict \Nvery loose timeframes.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,To predict more imminent events,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,researchers have investigated the \Nvibrations Earth elicits before a quake.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Geologists have long used seismometers
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to track and map these tiny shifts\Nin the earth’s crust.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,And today, most smartphones are \Nalso capable
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of recording primary seismic waves.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,With a network of phones around the globe,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,scientists could potentially \Ncrowd source a rich,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,detailed warning system that alerts \Npeople to incoming quakes.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Unfortunately, phones might not be able\Nto provide the advance notice needed
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to enact safety protocols.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But such detailed readings would still be \Nuseful
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,for prediction tools like NASA’s \NQuakesim software,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,which can use a rigorous blend of \Ngeological data
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to identify regions at risk.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,However, recent studies indicate
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,the most telling signs of a quake might be\Ninvisible to all these sensors.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,In 2011,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,just before an earthquake struck \Nthe east coast of Japan,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,nearby researchers recorded surprisingly \Nhigh concentrations
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,of the radioactive isotope pair \Nradon and thoron.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,As stress builds up in the crust right \Nbefore an earthquake,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,microfractures allow these gases \Nto escape to the surface.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,These scientists think that if we built \Na vast network of radon-thoron detectors
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,in earthquake-prone areas,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,it could become a promising \Nwarning system–
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,potentially predicting quakes \Na week in advance.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,Of course,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,none of these technologies \Nwould be as helpful
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,as simply looking deep inside \Nthe earth itself.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,With a deeper view we might be able
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,to track and predict large-scale \Ngeological changes in real time,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,possibly saving tens of thousands \Nof lives a year.
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,But for now,
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,these technologies can help us prepare \Nand respond quickly to areas in need–
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,without waiting for directions \Nfrom a vase.