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Earth Matters

Pulse Flow Ecosystem Restoration Sites

April 30th, 2014 by Adam Voiland


Scientists involved in the Minute 319 “pulse flow” say the effort has achieved its main objective: delivering water to special ecological restoration zones along the Colorado River. While cottonwood and willows have retreated from most areas due to a lack of water, conservation groups including the Sonoran Institute and Pronatura Noroeste have been working to revive ecosystems in areas where there is good soil and perhaps enough groundwater and farm runoff to support forests.

At the Laguna Cori, Laguna Grande, and CILA sites, for instance, the Sonoran Institute has been planting saplings, removing invasive plants, and grooming the landscape to make it more likely for trees to germinate. On April 16, 2014, the Operational Land Imager (OLI) on Landsat 8 observed water from the pulse flow replenishing wetlands in these area with water. For comparison, the lower image was acquired on March 31, 2014. The aerial image at the top of the page, first published by the Sonoran Institute, shows the Laguna Granda ecological zone inundated with water on April 14, 2014.

April 16, 2014

March 31, 2014

While greening is not yet visible to Landsat 8, the effects of the pulse flow are visible at ground level. On April 29, the Sonoran Institute began tweeting some of the first images of tree seeds germinating in response to the flow.

To learn more about the pulse flow, read Restoring a Pulse to the Lower Colorado and A River Renewed.


April Puzzler Answer: Yosemite’s Granite

April 25th, 2014 by Adam Voiland

Congratulations to Earth Matters reader Mike G. for being the first to solve our April Puzzler! As Mike pointed out, this image shows granite outcrops in Yosemite National Park. Over on Facebook, Cooper Girard was the first to get the location; he also sagely noted that Yosemite’s landscape is the product of a granitic pluton being uplifted by tectonic processes and then sculpted by glacial ice.  Read our April 26, 2014, Image of the Day for more details about the image, which was captured by the Landsat 8 satellite. After you’ve looked over the satellite image, check out this gallery of historical photography from U.S. Geological Survey geologist Francois Matthes showing many granite outcrops in the park.  I’ve included a few of my favorite shots of Nevada Falls, Liberty Cap, Cascade Cliffs, and Mount Starr King below, but there are many more to see. At the very bottom of this post, you can also watch a nice video featuring geologists explaining how the granite formed.

Yosemite National Park, California. Giant Stairway from Glacier Point. In the center is Nevada Fall, which leaps from the upper step, flanked by Liberty Cap. Below is Vernal Fall, which leaps from the lower step. On the far side of Little Yosemite Valley, which is behind Liberty Cap, are the water-streaked Cascade Cliffs, and beyond are the peaks of the High Sierra mantled with snow. At the left is Mount Florence. At the right is Mount Clark. Photo by A.C. Pillsbury, circa 1914. Plate 10, U.S. Geological Survey Professional paper 160.
Yosemite National Park, California. Front of Liberty Cap and Mount Broderick. Their sheer, hackly fronts were subjected to the quarrying action of the Merced Glacier. The V-shaped cleft between them was gouged out along a narrow zone of shattered rock. Circa 1914. Plate 44-B, U.S. Geological Survey Professional paper 160.
Yosemite National Park, California. End of an exfoliating spur on the west side of the Starr King group. This spur was not overtopped by the earlier ice. It owes its smoothly rounded form wholly to exfoliation. Circa 1913.
Yosemite National Park, California. Little Yosemite Valley. Through this broad antechamber the Merced River approaches the main valley. On the right are the Cascade Cliffs streaked by innumerable temporary cascades; on the left is Sugar Loaf (Bunnell Point). Circa 1914. Plate 4-A, U.S. Geological Survey Professional paper 160.

April Puzzler

April 21st, 2014 by Adam Voiland


Every month we offer a puzzling satellite image here on Earth Matters. The April 2014 puzzler is above. Your challenge is to use the comments section to tell us what the image shows, what part of the world we are looking at, when the image was acquired, and why the scene is interesting.

How to answer. Your answer can be a few words or several paragraphs. (Try to keep it shorter than 200 words). You might simply tell us what part of the world an image shows. Or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure speck in the far corner of an image. If you think something is interesting or noteworthy, tell us about it.

The prize. We can’t offer prize money, but, we can promise you credit and glory (well, maybe just credit). Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. In the credits, we’ll acknowledge the person who was first to correctly ID the image. We’ll also recognize people who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have played a role in molding the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you want us to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the last few months or work in geospatial imaging, please sit on your hands for at least a few days to give others a chance to play.

Releasing Comments. Savvy readers have solved many of our puzzlers after only a few minutes or hours. To give more people a chance to play, we may wait between 24-48 hours before posting the answers we receive in the comment thread.

Aerial View of Kahauale‘a 2

April 11th, 2014 by Adam Voiland

The Earth Observing-1 (EO-1) satellite was orbiting at an altitude of about 700 kilometers (400 miles) when it captured our April 11 Image of the Day    a nadir view of Kilauea’s Kahaualeʻa 2 lava flow creeping through forests northeast of Pu’u ’O’o crater. Much closer to the surface, the U.S. Geological Survey monitors the lava flow with helicopter overflights.

The image below shows a portion of the flow as it appeared on March 7, 2014. The smoke near the flow front is caused by lava burning trees and other vegetation in ohia lehua forests. Gases emanating from the vent are visible on the upper left.

(Credit: US Geological Survey/Hawaiian Volcano Observatory)

For more aerial imagery of Kahaualeʻa 2, visit the Hawaiian Volcano Observatory’s multimedia page. The image below was acquired by satellite on March 11, 2014. Click on it for more details.


For the second year in a row, an image from the Canary Islands took the championship of Tournament: Earth. In 2013, a submarine volcano near El Hierro Island was the crowd favorite. This year, it was a shot of the entire island chain that dominated the vote. When “Trailing the Canaries” faced “Activity at Kliuchevskoi” in the championship round, it wasn’t just a win for the Canaries image; it was a blowout. Of the nearly 50,000 votes cast, 96 percent went to the Canary Islands image.

To salute our many readers from the Canaries, we’ve combed through our archives and selected five of our all-time favorite images involving the island chain. They are posted below from oldest to newest. Click on each image for more details. Enjoy!

Dust over the Canary Islands (March 2009)

Teide Volcano (July 2009)

Sand and Tourism in Gran Canaria (January 2013)

El Hierro Submarine Volcano Eruption (2013 Tournament Earth Champion)

Trailing the Canaries (2014 Tournament Earth Champion)