Earth Science Picture of the Day

Green River Panorama

2012-02-27T03:01:00-05:00

Photographer: Stephen J Gledhill; Stephen's Web page
Summary Authors: Stephen J Gledhill; Stu Witmer

This image was captured a couple of minutes after sunrise on September 27, 2011 from the Labyrinth campground on the western side of the White Rim Trail in Canyonlands National Park, Utah. The Sun is directly behind me and casts the shadow of the Green River valley rim onto the cliff face on the opposite side of the river. The stillness of the morning helped create a striking reflection on the river. A few minutes after this picture was taken it was business as usual for daytime in the park - bright, glaring, baking hot sun.

The Green River’s source is in the Green River Lakes on Gannett Peak, Wyoming’s highest mountain. In its 730 mi (1,175 km) course, the river has an average descent of 13 ft/mi (2m/km). It's the largest tributary of the Colorado River system with a catchment area of 45,000 sq mi (116,500 km2). The greenish color of the water, and the river's name, is most likely derived from the green soapstone in some of its banks.

Photo details: Camera Model: Canon EOS 7D; Focal Length: 15mm lens (24mm - equivalent to a 35mm on a full frame camera); Aperture: f/11; Exposure Time: 0.040 s (1/25); ISO equiv: 200; Software: Adobe Photoshop Camera Raw 6.6 (Windows). The picture was created by stitching together a series of six vertical format frames taken in rapid succession to create the 180-degree panorama.

Dodecahedron Geode

2012-02-26T03:01:00-05:00

Photographer: Alana Ketcham
Summary Authors: John Stetson; Stu Witmer

My photography student, Alana Ketcham, and I were pleasantly surprised to find a dodecahedron inside this geode at the L.C. Bates Museum. A dodecahedron is a solid composed of twelve regular pentagons, and it is one of the Platonic solids. In Ancient Greece, the Pythagoreans believed that these solids were fundamental to the universe. More recently, a group of cosmologists have proposed that our universe may be shaped like a dodecahedron (Poincare Dodecahedron Space).

Since the crystal in the picture appears to be a dodecahedron, and crystals are made of the most efficient packing of atoms, the atomic structure of this crystal would likely consist of dodecahedrons. That would mean that there are many, many dodecahedrons to be found. A Dodecahedron even appears in the novel, "The Phantom Tollbooth"; that's where Alana, the photographer, first encountered a dodecahedron.

Geode, meaning "earthlike", is a good description for the shape of these surprising rocks. The plain-looking chalcedony exterior, called a "rind", often hides a stunning crystalline interior of quartz or other rock crystal, in this case calcite. Geodes form as concretions in cavities as diverse as air bubbles in rocks or tree roots. Over time, they gain a shell that’s penetrated by water dissolving the interior rock and allowing crystals to grow from minerals brought in by the water. Photo taken October 23, 2011.

Photo details: Camera Maker: NIKON CORPORATION; Camera Model: NIKON D300; Focal Length: 105.0mm; Aperture: f/20.0; Exposure Time: 0.0040 s (1/250); ISO equiv: 200; Exposure Bias: none; Metering Mode: Center Weight; Exposure: Manual; Light Source: Unknown; Flash Fired: Yes (enforced, return light not detected); Orientation: Normal; Software: Adobe Photoshop CS Windows.

White Christmas on Bermuda?

2012-02-25T03:01:00-05:00

Photographer: Declan G. De Paor; Declan's Web site
Summary Author: Declan G. De Paor

This photo was taken Christmas Day 2011 on the island of Bermuda. At first glance, it appears that dreams of a White Christmas became reality on Bermuda -- all the roofs look snow-covered. However, it never snows or freezes in Bermuda. The Gulf Stream helps keep temperatures above 50 F (10 C) throughout the year. Virtually all of Bermuda's roofs are white. The roofs are constructed from limestone shingles using a wooden frame. They're mortared and coated with cement, and then finished with a traditional lime wash or a modern non-toxic paint. This keeps rain water as clean as possible while gutters direct rainfall runoff into storage cisterns below ground. Although there's no snow on Bermuda, it rains often -- more than 200 days per year. In fact, rainfall is the island's main source of water since there are no rivers or lakes on the island. By law, Bermuda residents must collect 80 percent of their household water by utilizing the roof runoff and cistern method. Note the crepuscular rays below the palm fronds.

Lightning Display on Ikaria Island, Greece

2012-02-24T03:01:00-05:00

Photographer: Chris Kotsiopoulos
Summary Author: Chris Kotsiopoulos

This 70-shot photo sequence shows a lightning display that occurred during a severe thunderstorm last summer on the island of Ikaria, Greece, near the southwestern coast of Turkey. The stormy weather actually developed during my photo session of the total lunar eclipse on June 15, 2011 (see related link below). To make this shot, I set my camera on a tripod taking 20-second exposures continuously. More than 100 lightning bolts were captured in this sequence, the majority of which were potent cloud-to-ground strikes.

Photo details: Canon EOS 550D camera; shutter speed of 20 seconds (70 shots); 7.1 aperture; ISO 400; Canon EF 50mm, f/1.8 II lens; 50.0 mm focal length. Photo sequence taken on June 16, 2011 between 1:17 a.m. and 2:40 a.m.

Arch Rock on Mackinac Island, Michigan

2012-02-23T03:01:00-05:00

Photographer: Chloe Cook; Mona Shores Public Schools
Summary Author: Matthew L. Schuchardt; Chloe Cook

Pictured above is Arch Rock on Mackinac Island, Michigan. Arch Rock is a natural limestone/breccia formation on the shoreline of Lake Huron, standing 146 ft (45 m) above the lake level. It's believed to have formed about 5,000 years ago during the Nipissing stage of high water levels on Lake Huron. Limestone/breccia formations are rather unusual in the Great Lakes region, although the arch is one of several such formations on Mackinac Island -- others include Sugar Loaf and Skull Cave. Northern white cedars (Thuja occidentalis) have taken hold in the rocky crevasses below the arch. Photo taken in June of 2009.

Glacial Till on Cape Breton Island

2012-02-22T03:01:00-05:00

Photographer: Peter Jacobson
Summary Author: Peter Jacobson

The photo above showing glacial till on a terrace cut was taken near Cabot Landing Provincial Park in the northeast corner of Cape Breton Island. The Gulf of St. Lawrence is in the background. This natural cut, approximately 5 ft (1.5 m) in height, demonstrates the heterogeneous and unstructured nature of glacial till. The cobble-sized clasts match well with local granite bedrock, indicating that their provenance must be local. Photo taken on July 27, 2011.

Photo details: Camera Maker: NIKON CORPORATION; Camera Model: NIKON D80; Lens: Tokina AT-X 116 PRO DX (AF 11-16mm f/2.8); Focal Length: 11mm (35mm equivalent: 16mm); Aperture: f/7.1; Exposure Time: 0.0050 s (1/200); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; White Balance: Auto; Flash Fired: No; Orientation: Normal; Color Space: sRGB; Software: Aperture 3.2.2.

Hoces of the River Duraton

2012-02-21T03:01:00-05:00

Photographer: F.J. Pobes; Fernando's Web site
Summary Author: F.J. Pobes; Jim Foster

The photo montage above shows the Hoces of the River Duraton in north central Spain, in the province of Segovia. This scenic natural park consists of impressive 15 mi (25 km) long gorges ("hoces") created by the Duraton River as it loops its way to the Douro River, to eventually empty into the Atlantic Ocean. The wide meanders of the Duraton have, over the eons, eroded into limestone rock – the resulting cliffs tower 330 ft (100 m) above the river. Natural caves formed in these cliffs house ceramics and paintings that date to the Bronze age. The canyon walls are also prime nesting sites of one of the largest colonies of griffon vultures (Gyps fulvus) in Europe. Junipers line the slopes leading down to the river. Photo taken on January 29, 2012.

Photo details: Canon 350d camera; sigma 28-70; 70-300 APO; 3-photo panorama.

Galactic Storm

2012-02-20T03:01:00-05:00

Photographer: Bret Webster; Bret’s Web site
Summary Author: Bret Webster; Jim Foster

The photo above showing the Milky Way stretching across the desert sky and a distant monsoon thunderstorm on the horizon was captured just outside of Dead Horse Point State Park in Utah. I had been out taking some nighttime images of the sky in Canyonlands National Park, but as I was driving towards Dead Horse Point, I realized that the Milky Way was aligning perfectly with a thunderstorm cell well to the south of my location. So, I popped out of the car and snapped this shot. Fortunately, the sky overhead was still clear and very dark. The anvil top of the cumulonimbus cloud was just below the central portion (densest area) of the Milky Way. Altair is the bright star at upper left center – in the constellation of Aquila. Just above and to the left of the cloud tops the constellation of Sagittarius can be seen. Corona Australis is the semielliptical grouping of stars below Sagittarius and to the left of the storm. Photo taken on August 27, 2011.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 5D Mark II; Lens: EF15mm f/2.8 Fisheye;
Focal Length: 15mm; Aperture: f/2.8; Exposure Time: 30.000 s; ISO equiv: 3200; Exposure Bias: none; Metering Mode: Matrix; Exposure: Manual; Exposure Mode: Manual; White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: Adobe RGB (1998); Software: Adobe Photoshop CS5.1 Windows.

Rainbow Over Korbach, Germany

2012-02-19T03:01:00-05:00

Photographer: Stefan Pleister; Stefan's Web site
Summary Authors: Stefan Pleister; Jim Foster

The photo above showing a handsome rainbow arching over lush green fields near Korbach, Germany was taken at a meeting of amateur astronomers. An afternoon thundershower had just moved through the area and while waiting for our evening viewing session this primary rainbow quickly got our attention. Although it seems close at hand, there's no specific distance from onlookers where a rainbow can be exactly located. Attempting to photograph a complete rainbow sweeping across the landscape, like the one above, can be exasperating since a typical camera (35 mm) has a field of view that's smaller than the angular size (42 degree angle) of the primary bow. This also holds true if you're trying to snap a picture of a rainbow formed by the spray of a fountain -- the angular size of such a bow is still 42 degrees. If you want to capture the entire bow, use a fisheye or wide-angle lens. Photo taken on August 20, 2011.

Badlands Mirage

2012-02-18T03:01:00-05:00

Photographer: Kelly Whitaker
Summary Author: Kelly Whitaker; Jim Foster

With its odd landform shapes, the Badlands of South Dakota sometimes gives one the sense of being on another planet. These badlands, primarily highly eroded, exposed sedimentary strata, can look particularly strange when a temperature inversion results in a superior mirage, causing them to loom. With this type of a mirage, the refracted image appears above the true image. Shown above is a superior mirage or Fata Morgana that formed on the horizon, some 60 mi (100 km) away, just after sunup in late December 2011. The cold morning air settled close to the ground, but the layer of air just above it was several degrees warmer. In essence, light coming from the distant landforms passing upward through the warmer air was bent downward so that the miraging objects looked to be above their actual (not refracted) position. Photo taken on December 28, 2011.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS DIGITAL REBEL XTi; Focal Length: 109.0mm; Lens: Tamron 70-300 mm; Aperture: f/7.1; Exposure Time: 0.050 s (1/20); ISO equiv: 400; Exposure Bias: none; Metering Mode: Average; Exposure: Manual; White Balance: Auto; Flash Fired: No (enforced); Color Space: Adobe RGB (1998); Software: Adobe Photoshop Elements 9.0 Windows.