When Nature Strikes: Volcanoes

Air Date: 09/24/2015
Source:
NBC Learn
Creator:
Dr. Marshall Shepherd
Air/Publish Date:
09/24/2015
Event Date:
09/24/2015
Resource Type:
Science Explainer
Copyright:
NBCUniversal Media, LLC.
Copyright Date:
2015
Clip Length:
00:05:30

Volcanoes are one of the most powerful natural hazards on Earth, but supervolcanoes are so large that they have the ability to alter the world's climate. Michael Manga from the University of California, Berkeley is investigating a supervolcano that erupted hundreds of thousands of years ago, and could do so again. "When Nature Strikes" is produced by NBC Learn in partnership with the National Science Foundation and The Weather Channel. For a classroom activity related to this video, please click the Links section below.

When Nature Strikes -- Volcanoes

MARSHALL SHEPHERD reporting:

No other natural disaster has the explosive force of volcanoes. Their eruptions can send ash plumes dozens of miles into the sky and unleash rivers of 2,000-degree Fahrenheit lava. But the biggest eruptions of all come from supervolcanoes, which have the ability to impact life around the planet. They have done so in the past, and they will happen again. Michael Manga is a geologist at the University of California, Berkeley, and is funded by the National Science Foundation. He's learning a lot about the threat of supervolcanoes today, by looking at one that took place long ago.

Seven hundred and fifty thousand years ago, this beautiful area in the Sierra Nevada Mountains of northern California was the scene of an Armageddon. A volcanic eruption occurred that was so large it collapsed the mouth of the volcano and left a 20-mile-wide crater, called a caldera. Known as the Long Valley Caldera, this "super" volcano's eruption spread debris across the western half of the United States, and its impacts were felt around the world.

MICHAEL MANGA (University of California, Berkeley): The smallest particles produced by this eruption are distributed across the whole planet. You can find them in sediments pulled out of the Pacific Ocean.

SHEPHERD: Many adults today remember when the Mount St. Helens volcano in Washington State erupted in 1980, killing 57 people. The ash cloud it created reached 15 miles high. As cataclysmic as the Mount St. Helens eruption was, it pales in comparison to the eruption at Long Valley.

MANGA: When this eruption occurred, the big caldera-forming eruption, it would've been basically a thousand times bigger than Mount St. Helens in terms of the mass erupted.

SHEPHERD: Geologist Michael Manga has been studying the Long Valley Caldera to not only research this epic natural disaster, but also to understand the behavior of volcanoes around the world in order to better predict their impacts.

MANGA: Our interest is understanding how and why volcanoes erupt, why they exist. By studying fossil or old volcanoes like Long Valley, we get a better understanding of how volcanoes work.

SHEPHERD: Volcanoes come in all shapes and sizes, from flat shield volcanoes like Kilauea, in Hawaii, to towering stratovolcanoes like Mount St. Helens. But the characteristics of a volcano are determined by what's happening deep below earth's surface.

MANGA: Almost all volcanoes are ultimately controlled by what's happening deep underneath the crust. In the place we call the mantle. When mantle inside the earth rises vertically, when it gets close to the surface, it can start to melt.

SHEPHERD: This produces magma, made partly of molten rock, that rises through fractures in the Earth's crust. Various combinations of molten rock and gases are pushed further to the surface causing pressure to build up until there is a rupture, triggering a volcanic eruption. But in a supervolcano, the magma is unable to push through the crust and it pools to form massive magma chambers. Over time, the pressure continues to build until the crust finally gives way in an explosion several miles wide.

MANGA: These super volcanoes, they're so big that it's hard to imagine how big the eruption would have been.

SHEPHERD: The Long Valley Caldera is only one example. There is another supervolcano in the United States that geologists are watching even more closely.

MANGA: The other place most famous for its supervolcanoes is Yellowstone National Park. We can see magma, molten rock, under the ground. So there is a good chance at some point in the future, there will be an eruption.

SHEPHERD: The famous geysers and hot springs at Yellowstone are all examples of volcanic activity caused by magma below the surface. If Yellowstone were to have a super-eruption today, not only could it interrupt your weekend flight plans, it could also impact agriculture on a massive scale, and even alter the climate, so much in fact, that it could endanger certain species with extinction, including humans. But enough is known about volcanoes that Manga believes, for now at least, Yellowstone is still biding its time.

MANGA: There is no reason to think there will be an eruption anytime in the very near future.

SHEPHERD: With the help of scientists like Manga, more is being learned about the behavior of volcanoes and the magma inside them. The research will help improve the ability to predict not just when a volcano will erupt, but also what the eruption will look like-- information that could save thousands of lives.

Close NBC Learn

FILTERING

If you are trying to view the videos from inside a school or university, your IT admin may need to enable streaming on your network. Please see the Internet Filtering section of our Technical Requirements page.

DVDs AND OTHER COPIES

Videos on this page are not available on DVD at this time due to licensing restrictions on the footage.

DOWNLOADING VIDEOS

Subscribers to NBC Learn may download videos and play them back without an internet connection. Please click here to find out more about subscribing or to sign up for a FREE trial (download not included in free trial).

Still have questions?
Click here to send us an email.

Close NBC Learn

INTERNATIONAL VISITORS

The Science of the Olympic Winter Games videos are only available to visitors inside the United States due to licensing restrictions on the Olympics footage used in the videos.

FILTERING

If you are trying to view the videos from inside a school or university, your IT admin may need to enable streaming on your network. Please see the Internet Filtering section of our Technical Requirements page.

DVDs AND OTHER COPIES

The Science of the Olympic Winter Games is not available on DVD at this time due to licensing restrictions on on Olympic footage.

DOWNLOADING VIDEOS

Subscribers to NBC Learn may download videos and play them back without an internet connection. Please click here to find out more about subscribing or to sign up for a FREE trial (download not included in free trial).

Still have questions?
Click here to send us an email.

Close NBC Learn

Choose your product

NBC Learn K-12 product site
NBC Learn Higher Ed product site

For NBC Learn in Blackboard™ please log in to your institution's Blackboard™ web site and click "Browse NBC Learn"

Close NBC Learn

If you have received a new user registration code from your institution, click your product below and use the "Register now" link to sign up for a personal account.

NBC Learn K-12 product site
NBC Learn Higher Ed product site

For further assistance, please contact our NBC Learn Support Team and we'll be happy to assist you.

Start Your Free
day
Day Trial!