Watch How Life Recovers from Devastation

by Nancy Atkinson on May 17, 2012

If a portion of Earth underwent a major cataclysm, how long would it take for life to recover? The 1980 eruption of Mount St. Helens is giving scientists an unprecedented opportunity to witness a recovery from devastation, as the eruption leveled the surrounding forest, blasted away hundreds of meters of the mountain’s summit, and claimed 57 human lives. Landsat satellites have tracked the what has happened on the mountain, and how the forest was reclaimed — all on its own. This video shows a timelapse of the recovery, with annual images from 1979-2011 from the Landsat satellites, which acquired the images seen here between 1979 and 2011.

The animation begins with vegetation as red because early Landsat satellites couldn’t ‘see’ blue light. That changed with launch of Landsat 5 in 1984 and its natural color abilities.

The collapse of the mountain was like uncorking a bottle of champagne. Fifty-seven people died when rocks, hot ash, gas and steam exploded out of the Earth. The blast debris, which is gray in the images, covered over 230 square miles (600 square kilometers) and blew down 4 billion board-feet of timber.

The landslide buried 14 miles (23 kilometers) of the North Fork Toutle River with an average of 150 feet (46 meters) of rocks, dirt and uprooted trees. In some places the debris was as deep as 600 feet (180 meters) high.

The squarish beige patches visible in the upper right and lower left of the animation show logging on the mountain both before and after the eruption.

This image was created using the reflected light from the near infrared, green and red portions of the spectrum from instruments aboard Landsat satellites 2 and 3 and from the blue, green and red portions of the spectrum from instruments aboard Landsat satellites 5 and 7.

Landsat 2 launched in 1975 and provided scientific data for 7 years until 1982. Landsat 3 launched in 1978 and ran for 5 years until 1983. NASA launched Landsat 5 in 1984 and it ran for a record-breaking 28 years. Landsat 7 is still up and running; it was launched in 1999. The data from these and other Landsat satellites has been instrumental in our understanding of forest health, storm damage, agricultural trends, urban growth and many other ongoing changes to our land.

The next Landsat satellite, now known as the Landsat Data Continuity Mission (LDCM) and later to be called Landsat 8, is scheduled for launch in 2013.

The 40-year archive of Landsat images that is freely available to anyone at this link.

About 

Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

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