([syndicated profile] epod_feed Jun. 29th, 2017 03:01 am)



Photographer: Dale Hugo 

Summary Author
: Dale Hugo

Alas, my 60-some-year-old black locust tree (Robinia pseudoacacia) may be on the way out. Both of the red-belt conk (Fomitopsis pinicola) shelf fungi featured above sprouted suddenly last summer. They're both about 8 in (20 cm) wide and are approximately 8 in (20 cm) above the ground surface. These fungi may indicate that there's dead wood at the base of the tree. Note that the fruiting body on the photo at bottom is brown and rather dried out. This one's on the south side of the tree and receives a lot of direct sunlight. However, its purplish red neighbor (top photo) found on the north side of the trunk, has retained its color.

Other than the unsightly growths, the tree seems healthy with decent growth in the canopy last summer. I estimate that the trunk and branches weigh perhaps 18,000 lbs (8 metric tons), without leaves, and that it's a little over 33 ft (10 m) in height and is 7 ft (2.25 m) in diameter at breast height. It's placed on the southeast corner of our suburban lot where my wife and I have lived for 46 years -- arriving after the tree was already a sapling, but only about 4 in (10 cm) in diameter. Trees grow whether you notice them or not! If this big fella has to go there would certainly be a lot of firewood I could burn and leftover wood for fencing too, but all in all, I hope he's healthy enough to stick around a few more years.

Photo Details: Top - Camera Maker: Apple; Camera Model: iPad 2; Lens: Apple; Focal Length: 2.0mm (35mm equivalent: 44mm); Aperture: ƒ/2.4; Exposure Time: 0.017 s (1/60); ISO equiv: 50. Bottom: Same except - Exposure Time: 0.0032 s (1/315); ISO equiv: 40.

EPOD.YosemiteWaterfall2017_2 (1)

Photographer: Thomas McGuire
Summary Author: Thomas McGuire
After years of drought conditions, 2016-17 has been a year of roughly twice the historical average snowfall in the Sierra Nevada. Waterfalls that had flowed below average for years are in flood this year, as shown above at Yosemite Falls, bringing record attendance to Yosemite through May. The observation point near the base of Bridalveil Fall is so wet that tourists are getting soaked, without a view of the falls, due to the heavy mist.

The Merced River has been at or near flood level for weeks. Some campgrounds that are normally open this time of year are currently flooded. Tioga Road across the Sierras, normally closed by snowpack until early May, is unlikely to open this year before the end of June. Across the Sierras, Mammoth Mountain ski area is projected be hosting skiers into August.

However, the winter season rain and snow wasn't enough to end the drought in California completely. Reservoir levels have recovered, but it may take years for groundwater levels to return to normal. Photo taken on May 30, 2017.

Photo Details: Camera Model: Canon EOS REBEL T5; Lens: EF-S18-55mm f/3.5-5.6 IS II; Focal Length: 20.0mm; Aperture: ƒ/9.0; Exposure Time: 0.0050 s (1/200); ISO equiv: 100; Software: Adobe Photoshop Elements 9.0 Macintosh. 
([syndicated profile] epod_feed Jun. 27th, 2017 03:01 am)

Suncorona_ 2-4-2017 (4)

Photographer: Greg Gardella

Summary Authors: Greg Gardella; Jim Foster

Shown above is a particularly colorful corona as observed over Reno, Nevada, right after a storm cleared the area. Though this image was taken with a cell phone camera, it looks as it did to my naked eye. However, most coronas aren't as vivid as this one. Coronas result when sunlight is diffracted by cloud droplets, most often in mid-level clouds. These droplets impede rays of sunlight in such a way to generate successive interference rings. Note that smaller droplets cause larger (wider) rings. Always use caution when looking anywhere near the Sun. Photo taken on February 4, 2017.

([syndicated profile] epod_feed Jun. 26th, 2017 03:01 am)

Moon_sun_halo_5 (3)

Photographer: Hubert Drozdz

Summary Authors: Hubert Drozdz; Jim Foster

The image above is a composite of a solar and lunar 22 degree halo as observed 18 days apart, from the same location (Radomsko, Poland), and using the same photographic equipment. The solar halo was taken on March 19, 2017, at 3:30 PM; the lunar halo was captured on April 6, 2017, at 11:00 PM -- the Moon was in the gibbous phase.

Moonlight or sunlight shining through six-sided (pencil-shaped) ice crystals that compose cirrus clouds result in 22 degree halos. Light first passes through the side faces of the randomly oriented (more or less) crystals, is refracted 22 degrees and then exits through one of the crystal's alternate side faces. Though the lunar halo may be more conspicuous than the solar halo, especially if the Moon is full, the colors are harder to detect since the Moon is a weak light source in comparison to the Sun.

Photo Details:  Canon EOS 450D camera; Samyand 8mm (Fish-Eye) lens; Adobe Photoshop CS 4. 

Roll1dx-21 copy

Each Sunday we present a notable item from our archives. This EPOD was originally published June 25, 2003.

Provided by: Robert Moriarity

Summary authors & editors: Martin Ruzek; Robert Moriarity

This picture shows a north facing beach erosion zone on Santa Rosa Island off the southern California coast. The island is part of the northern Channel Islands, a westward extension of the Southern California Transverse Ranges. Distinctive clastic lithologies connect Santa Rosa Island to the California mainland near San Diego, 200 km to the southeast, in the distant past. The islands have been sliced, rotated and translated northwestward as part of the San Andreas fault system. The photo above shows a layer of deformed fine-grained sediment between coarse clastic deposits, now eroding on the beach. Unraveling the story told by these rocks is part of the challenge of geology - perhaps a slumping course debris flow compressed soft intertidal mud or volcanic ash deposits? The best way to find out is to get out your field notebook and hand lens and take a trip to Santa Rosa Island! [Revised June 2017]

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EPOD_EncoreBrilliant Sun Pillar Over Jenison Michigan

Today and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.

Photographer: Kevin Povenz

Summary Authors: Andrew McFarlane; Jim Foster

May 2012 Viewer's ChoiceThe photo above showing a breathtaking Sun pillar was captured at sunset near Jenison, Michigan on April 10, 2012. Sun pillars result from the reflection of sunlight off the bottom surfaces (or less frequently, the top surfaces) of plate-shaped ice crystals composing cirrus clouds. These crystals must be similarly oriented and slightly tipped with respect to the viewer in order for a pillar to be observed. The crimson shaft piercing the purple sky made this sunset unforgettable.

Photo Details: Canon T1i camera; Sigma 18 - 200mm lens; Exposure - 0.125 sec. (1/8) exposure; f/9 aperture; 63mm focal length; 100 ISO; Software - Adobe Photoshop elements 9.0.  


Photographer: Rebecca Roush

Summary Author: Rebecca Roush

Gravitational waves are currently being researched intensely at the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Hanford, Washington. Construction of the observatory and landscaping around it has resulted in two interesting and related phenomena: first, tumbleweeds can affect the measurements of gravitational waves and second, baling tumbleweeds provides Western Kingbirds with materials to build their nests in the observatory’s landscaping.

Baling machines are used to collect tumbleweeds that gather around the site’s buildings, including the observatory’s 2.5 mile-long arms. If not baled, tumbleweeds have the potential to affect the very sensitive instruments measuring gravitational waves. The bundles are secured with string, which opportunistic Western Kingbirds use to build their nests.

The photo on the left shows the baling equipment and some tumbleweeds beginning to accumulate near one of the observatory's extended arms. Once baled, they're distributed around the surrounding arid landscape to decompose. The photo on the right shows several kingbird nests in a planted deciduous tree on the observatory grounds. Note the red baling twine that the opportune birds have incorporated into their nests, making them look almost like decorations. Photo taken on April 19, 2017. 

([syndicated profile] epod_feed Jun. 22nd, 2017 03:01 am)

LagunaPanorama (1)

Photographer: Daniel Puerta Sanchez

Summary Authors: Daniel Puerta Sanchez; Jim Foster

Shown above is an attention-getting reflection off the still waters of Laguna Larga in north-central Spain. This small lake is one of the eight lakes that form Lagunas de Neila; each occupies a cirque carved by glaciers in the Sierra de la Demanda. While it can be a challenge to discern the reflected image from the actual image when water is calm and clear, the reflected image is always slightly dimmer, except when the incidence angle (the angle made by the camera lens, the water surface and the Sun) is exactly 90 degrees. Note that Laguna Larga has the only floating peat bog found in Spain. Photo taken on April 2, 2017.

Photo Details: Panorama of 5 photos; Canon EOS 80D camera; Tokina 16 mm lens; ƒ/3.2; ISO 800; 1/8000 sec. exposure; Software: Adobe Photoshop CS6 (Windows).

([syndicated profile] epod_feed Jun. 21st, 2017 03:01 am)

Hraunfossar1 (2)

Photographer: Gísli Már Árnason

Summary Author: Gísli Már Árnason

Shown above are the Northern Lights and the stunning Hraunfossar (lava falls), in western Iceland. These falls are formed from a stream flowing underneath the Hallmundarhraun lava field -- the stream  empties into the Hvítá River.

As the daylight period lengthens in spring and summer the aurora season comes to an end. This pale green aurora resulted from a moderate geomagnetic storm (Kp6 classification) that occurred in late March. The bright star on the right is Vega, in the constellation of Lyra. The Milky Way is hidden behind the auroral curtain, but the Andromeda Galaxy, the closest major galaxy to the Milky Way, is visible at the lower left. Photo taken on March 27, 2017.

Photo Details: Camera Model: NIKON D810A; Lens: 35.0 mm f/1.4; Focal Length: 35mm (35mm equivalent: 35mm); Aperture: ƒ/1.4; Exposure Time: 5.000 s; ISO equiv: 6400; Software: Adobe Photoshop CS6 (Windows). 

([syndicated profile] epod_feed Jun. 20th, 2017 03:01 am)

Tabby Concrete-Sugar Mill-Kings Bay-Sheridan (1)

Photographer: Rob Sheridan

Summary Author: Rob Sheridan

Concrete is a ubiquitous building material consisting of aggregate bonded together by cement. The most common aggregates are sand and gravel, and the most common cements are based on calcium oxides formed by heating ground limestone. It's an inexpensive, durable and waterproof building material strong in compression with strength in flexion commonly added through internal steel mesh.

However, simpler concretes have been crafted throughout post-agricultural human history. Tabby concrete is a unique construct probably brought to the Americas by Spanish explorers from North Africa in the 1600’s. It was used extensively in the southeastern American colonies, taking advantage of huge ancient Native American oyster middens found along the seacoast. The calcium carbonate (CaCO3) shells were ground and heated, releasing carbon dioxide (CO2) and leaving behind calcium oxide (CaO) or quicklime which forms a strong cement when water is added. Before hardening, this cement was mixed with unheated oyster shells as aggregate and layered within wooden forms, creating durable Tabby concrete structures. With a background of bald cypress and Spanish moss, this photo highlights the walls of a long abandoned sugar mill near Kings Bay in coastal southeast Georgia -- its Tabby concrete walls standing tall for nearly 200 years. Photo taken on February 24, 2017.

Photo Details: Camera Maker: Apple; Camera Model: iPhone 5s; Focal Length: 4.2mm (35mm equivalent: 29mm); Aperture: ƒ/2.2; Exposure Time: 0.0083 s (1/120); ISO equiv: 50.

([syndicated profile] epod_feed Jun. 19th, 2017 03:01 am)

Tetrapod_DSCF0181 (1)

PhotographerRob Lawley

Summary Author: Rob Lawley

These tracks in the exposed rocks at the coast on Valentia Island, County Kerry, Republic of Ireland, were created 385 million years ago by a tetrapod as it waddled across soft mud probably near a coastal river. The animal was lizard-like and is one of the earliest known vertebrates to be able live outside the ocean and walk on land. In fact, these are the oldest in situ vertebrate fossil tracks in the world. Its vertebrate ancestors were fish that had begun to live and breed in shallow waters at the edge of rivers. They developed the ability to breathe out of water and once their fins had evolved into legs they were ready to colonize the land.

Before about 500 million years ago, animal life was confined to the oceans because fatal doses of solar ultraviolet radiation (UV) were still bombarding the Earth’s surface. However, the oxygenation of the atmosphere by phytoplankton in the oceans and primitive UV-tolerant land plants led to a buildup in concentrations of ozone in the upper atmosphere, sufficient to reduce the level of incoming ultraviolet light.

Surprisingly the tracks above were discovered as recently as 1992 as the Atlantic Ocean removed overlying layers of rock. The ocean's same erosive forces will remove the tracks forever in the not too distant future. Photo taken on April 9, 2017.

Photo Details: Camera Maker: FUJIFILM; Camera Model: FinePix S1500; Focal Length: 20.0mm;

Aperture: ƒ/3.3; Exposure Time: 0.013 s (1/80); ISO equiv: 64; Software: Digital Camera FinePix S1500 Ver1.03.  

([syndicated profile] epod_feed Jun. 18th, 2017 03:01 am)


Each Sunday we present a notable item from our archives. This EPOD was originally published June 21, 2003.

Provided by: NOAA

Summary Author:
Jim Foster

The Summer Solstice occurs today at 3:10 p.m. Eastern Daylight Time. At that moment, the Sun's rays will be positioned directly over the Tropic of Cancer (23 1/2 degrees north latitude). It's the longest day (length of daylight period) in the Northern Hemisphere and the first day of summer. The above GOES visible satellite image was taken yesterday from approximately 22,000 miles (35,200 km) above the Earth's surface. Note that while the top of North America and Greenland are fully illuminated, the bottom of the globe is dark -- it's the first day of winter in the Southern Hemisphere. The Arctic region (north of 66 1/2 degrees north latitude) is now experiencing 24 hours of daylight. [Revised June 2017]

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([syndicated profile] epod_feed Jun. 17th, 2017 03:01 am)


Today and every Saturday Earth Science Picture of the Day invites you to rediscover favorites from the past. Saturday posts feature an EPOD that was chosen by viewers like you in our monthly Viewers' Choice polls. Join us as we look back at these intriguing and captivating images.

Stereo Photographer: Brian May

Photographer: Greg Parker 

Summary Author: Greg Parker; Brian May

TApril 2012 Earth Science Picture of the Day Viewer's Choicehe stereo image above shows Comet Garradd as observed in early March 2012 from the New Forest Observatory in Brockenhurst, England. Its nearest approach to Earth occurred on March 5 when it was 117.7 million miles distant (1.27 astronomical units). At that time, Garradd was found near the bowl of the Little Dipper in the constellation of the Ursa Minor. Look for it now, with binoculars, near the bowl of the Big Dipper in Ursa Major.

This image is composed of two sub-images having a time separation of approximately 20 minutes. Note that in order to create this stereo pair, a bit of Photoshop manipulation is involved –- simply setting two sub-exposures side-by-side wouldn’t create such an impressive 3-D image. The pair can be viewed by free viewing and by using a stereo viewer such as the OWL. Click here for instructions on how to view using both of these methods. 

([syndicated profile] epod_feed Jun. 16th, 2017 03:01 am)

IC1396_Greg_Noel (2)

Photographer: Greg Parker

Summary Author: Greg Parker

Shown above is the emission nebula IC 1396, which includes the well-known Elephant's Trunk nebula, found in the constellation Cepheus. Oddly, it's one of the largest emission nebulae (HII regions) in the northern skies, but it doesn't have a common name -- it simply has a letter/number designation. This is quite remarkable given that far less imposing emission regions have been christened by astronomers from long ago.

IC 1396 is an immense structure. The dark round patch at its center that you can see in this image is almost the same diameter as a full Moon! Not only is it big, but it also contains many fascinating deep-sky objects, including the open star cluster Trumpler 37. This cluster is one of the youngest star clusters identified in our galaxy. In addition, IC 1396 holds star complex HD 206267, which though it doesn't look overly bright in this visible image, cradles a type of star emitting very strongly in the ultraviolet part of the spectrum (O6.5V) that's mostly responsible for the ionization of IC 1396.

Coming in from the right, just above the 3 o'clock position, we see the bright-rimmed scribble known as the Elephant's Trunk nebula, one of many globules sitting in IC 1396 that are home to star forming regions. Finally, at the top left of the image, we have a star that's difficult to miss; the brightest, reddest, naked-eye star in the Northern skies, Mu Cephei or Herschel's Garnet star (see the EPOD for July 6, 2014 - The Reddest Stars). Although extremely red, Mu Cephei is not a carbon star but is rather a red supergiant star rather like Betelgeuse in Orion.

With so much going on in and around IC 1396, isn't it time that this spectacular object was christened with a popular name? What would you call it?

Image Details: This image is a 2-frame mosaic taken with a Sky 90 refractor telescope and an M25C 6-Megapixel one shot color CCD imager. A total exposure time of 7 hours and 22 minutes in RGB (red, blue, green), and 11 hours and 40 minutes of narrowband H-alpha was devoted to making this image. The data was captured at the New Forest Observatory in Hampshire, the U.K. and was processed by Noel Carboni in Florida, U.S.A.