- [Narrator] Volcanic corruptions like this

may look mesmerizing and sometimes attract flux of tourists,

but they're also dangerous events

that impact human activities,

displace people, and cost lives.

- The prediction is that we did lose some 50% of our GDP

as a result of the volcanic eruption.

- [Narrator] Take this volcano

on the Caribbean island of St. Vincent.

No deaths were reported, but many people had to evacuate

and ash blanketed entire neighborhoods.

Or this Icelandic volcano that erupted in 2010,

paralyzing air traffic

and costing nearly $5 billion to global GDP.

So far, tools like seismicity monitors

have allowed volcanologists to forecast unrest

days or weeks in advance,

but now NASA scientists say they can help forecast eruptions

months or even years ahead of time using satellite imagery

and monitoring changes in ground temperature.

- We wanted to understand

to what extent the heat released by volcanoes can be used

to detect when volcanoes start to reactivate.

There are many impacts of volcanic eruptions

and our goal is to minimize those impacts

as much as possible.

- [Narrator] So here's how it works

and how scientists say we could benefit

from this new research.

An early sign of a volcanic eruption is heat,

as the magma underground rises,

bringing warm gases to the surface.

- We see that these heat emissions, they start to appear

for several months to years before eruption

and we observe these signals prior

to the changes that we observe with other types of signals.

- [Narrator] The problem is that these heat emissions

can be hard to monitor on the ground,

So Girona and his team turned to the sky.

NASA satellites have already been recording

years of information on thermal activity.

- In fact, none of these satellites have been designed

specifically to explore volcanoes,

but we can still use that information

for monitoring volcanic eruptions.

- [Narrator] After looking at two decades

of radiant heat data for several volcanoes,

the researchers found a pattern.

In the years leading up to interruption,

temperatures increased over much of each volcano

before dropping again after the eruption.

- [Tarsilo] We are detecting the early reactivation

of the volcano, which is crucial

to improve the monitoring efforts.

- [Narrator] But before this technology

can be fully deployed in the real world,

scientists will have to process much more data.

- Hopefully in a few years,

we can have a better understanding of the signals,

better understanding of volcanoes,

and we can provide accurate forecasts.

- [Narrator] With about 1,500 active volcanoes on Earth

and troves of satellite data for each one of them,

the NASA team is seeking help

from algorithms and other researchers around the world.

- This is another tool in our toolbox.

- [Narrator] That's Mike Poland.

He's a geophysicist for the U.S. Geological Survey.

He says that these satellite images will have to be used

in tandem with other traditional methods.

- If you're building a house,

you don't just show up with a screwdriver.

You've got a screwdriver, a hammer, a saw,

and we need a diverse toolkit

so that we can recognize all the different types of signs

that volcanoes might be giving us.

- [Narrator] Seismometers gas, sensors,

and radar sensors are some of the tools

that volcanologists will continue to use.

Giving communities more time to prepare

could make the difference between saving livelihoods or not.

In St. Vincent, the local observatory noticed signs

of unrest weeks in advance

and officials were ready to evacuate 20,000 residents

before the volcano erupted,

helping to avoid casualties and greater damage.

But with even more warning,

officials say they may have been able to avoid damage

such as water contamination, for example.

- When the massive eruption there took place,

it compromised our entire water supply.

All of our reservoirs were contaminated with ash.

We were without water for a couple of days

and perhaps going forward,

we can look at maybe putting in tents

where persons can store water properly.

We have to look at greater mitigation

where natural disasters are concerned.

- [Narrator] And in the case of that Icelandic volcano,

scientists say that more warning

would have given the aviation industry more time to adapt

and find alternative routes.

- It's important to forecast eruptions

because we can reduce the impact at a local scale,

but also at a global scale

if you're talking about much larger eruptions.

(tranquil futuristic music)