Forest Recovering from Mt. St. Helens Explosion

Mt. St. Helens exploded 32 years ago on May 18. It began with a small series of earthquakes and culminated with the volcano erupting, a cataclysmic collapse of the flank of the mountain and the largest landslide in recorded history.

This time series of data shows the explosion and subsequent recovery of life on the volcano. Landsat, a satellite program operated by NASA and the U.S. Geological Survey acquired the images between 1979 and 2011. In them, scientists have an unprecedented opportunity to witness how life recovers from devastation.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.

NASA Sees Fields of Green Spring up in Saudi Arabia

Saudi Arabia is drilling for a resource possibly more precious than oil.Over the last 24 years, it has tapped hidden reserves of water to grow wheat and other crops in the Syrian Desert. This time series of data shows images acquired by three different Landsat satellites operated by NASA and the U.S. Geological Survey.

The green fields that dot the desert draw on water that in part was trapped during the last Ice Age. In addition to rainwater that fell over several hundred thousand years, this fossil water filled aquifers that are now buried deep under the desert's shifting sands.

Saudi Arabia reaches these underground rivers and lakes by drilling through the desert floor, directly irrigating the fields with a circular sprinkler system. This technique is called center-pivot irrigation.Because rainfall in this area is now only a few centimeters (about one inch) each year, water here is a non-renewable resource. Although no one knows how much water is beneath the desert, hydrologists estimate it will only be economical to pump water for about 50 years.