The Earth Story

Life in a sinkhole The karst landscapes of China have been an essential part of their figurative art and painting since time immemorial, capturing the imagination and providing a sense of wonder at nature. The sinkholes here form when underground rivers carve out underground channels by chemical erosion whose roofs later collapse when they weaken. These windows allow sunlight to pour within, and extensive and unique ecosystems to develop underground. Loz Image credit: Song Wen/Barcroft Media http://on.wsj.com/1SdIVxD

Five-colored pool

As I was looking through photos of Jiuzhaigou National Park in China’s Sichuan Province, my eyes locked on the colors of this tiny pool, named Wǔcǎi Chí or the five-colored pool. The Park sits within Jiuzhaigou valley, a valley on the eastern side of Tibet with portions that rise in elevation to over 4800 meters. The area varies between dry glaciers at its highest elevations through a variety of forests and lakes at low elevations. Many of the lakes are the kind of classic features found in recently-glaciated country, filled by clear waters from the melting of ice and held in place by dams made of moraines and avalanches as the glaciers retreated.

Five-colored pool is just one of the many lakes in this park and just one of the many features worth viewing, but the combination of changing depths, cobbles at the bottom, different sunlight conditions as the day goes on, and changing water colors are making photos of it a treat for the eyes.

-JBB

Image credit: https://en.wikipedia.org/wiki/Jiuzhaigou#/media/File:1_jiuzhaigou_valley_five_colour_pond_2011.JPG

Read more: http://whc.unesco.org/en/list/637/ http://bit.ly/1ej1PUd http://bit.ly/1HxyMZq http://www.travelchinaguide.com/cityguides/sichuan/jiuzhaigou/

Tossing a bit of dust into the vertical light pillar in Antelope Canyon.

#Hawaii

Sunglint on African River NASA Astronaut Terry Virts took this beautiful photo. He states that it is a sunglint on a river in Angola. Sunglint is the mirror-like reflection of the sun off of the water directly back towards the camera. The color of sunglint depends on the roughness of the water, the angle of the observer, and the angle of the sun; for example, sunglint during sunset will look gold, rather than silver like this one does. The silver-appearance of the river as it cuts through the brown and green landscape certainly makes for a striking image. I can’t help but think that nature is trying to remind us that water is more precious than silver or gold. - RE Photo Credit: NASA References: http://earthobservatory.nasa.gov/IOTD/view.php?id=9072 http://www.livescience.com/45527-sunglint-lake-baikal.html

Sunset rainbows The light at sunset is reddened by its passage through the thick layers of atmosphere as it strikes our planet at a grazing angle increasing the path length of the rays, and this rainbow, snapped opposite the sun over Durban in South Africa is no exception. The blue wavelengths get scattered by the dust particles in the air, while the red pass through unimpeded, and the rainbow follows suit as the sun nears the horizon. Loz Image credit: Jacques Joubert

The first sunrise of the spring Snapped at Argentina’s Marambio base in Antarctica on November 10th last year, the solar orb is just reemerging above the horizon after its winter absence from the skies above the south pole during the annual long night and twilight. It heralds the beginning of the long summer day that will shine on the annual influx of scientists flying in to join the hardy souls who have overwintered and work on their various research projects, from astronomy and meteorite collecting to palaeontology and climate science. The still frozen Wedell Sea sits in the foreground. Loz Image credit: Jorgelina Alvarez via EPOD https://epod.usra.edu/

The best seats in the house...

This breath-taking image shows the Lovejoy Comet as it flew over the Southern Hemisphere back in December 2011 and of course, the staff of the International Space Station enjoyed a front seat view.

The expedition 30 crew captured video footage of the event and astronaut Dan Burbank describes the sight as “one of the most amazing things” he has ever seen in space- which let’s face it, is probably a tough competition!

The comet, officially labelled C/2011 W3, or Lovejoy to you and me, was discovered by Australian amateur astronomer Terry Lovejoy on Nov. 27, 2011. It is part of a family of comets known as Kreutz sungrazers, which are thought to be pieces of a much larger comet that broke up centuries ago but maintain the same orbit. They are termed sungrazers as their orbits take them near to the Sun, where radiation and the solar wind interact with the icy comet nuclei to produce striking visual displays of halos and tails. This journey of Lovejoy’s was feared to be its last with many scientists expecting it to be swallowed up by the Sun. But, alas, it survived.

Aside from the beautiful display of the comet, this image also hosts some of the features more close to home. The bright orange and yellow colours near Earth are light from the Sun being distorted by our atmosphere. Also visible is the Earth’s airglow, which you can see here as the green and the yellow colouration. Airglow occurs as a result of light being emitted by light and molecules in the upper atmosphere; excited by ultraviolet radiation.

All in all, this image is incredible and one can only imagine what it’s like to witness this sight first hand.

Jean

Image courtesy of NASA.

(The video is awesome: http://www.youtube.com/watch?v=fSsXY7oTm-c)

Hackmanite: The chameleon mineral.

A pink to purple variety of the mineral Sodalite (see http://on.fb.me/1IakMRj), it displays the weird property known as tenebrescence (aka reversible photochromism), a change of colour in response to sunlight or UV. Material from Quebec and Greenland starts off purple when wrested from the Earth, and fades to a greyish colour, while Burmese or Afghan material develops a strong violet to pink colour when exposed to sunlight that fades when the stone is left in the dark. The effect can be repeated at will (and is exploited in self darkening glasses), but heating the stone destroys it. The energy of the light creates or alters electronic colour centres in the crystal that selectively absorb wavelengths, leaving behind a residual colour such as the red of rubies. In this case it is the electrons of sulphur disseminated in the crystal structure that produce this eerie colour change capacity. Some people call it giving the stone a suntan, if you let Asian Hackmanite fade in the dark and then shine a UV light on it or open the curtain, a near instant colour change results (while it takes a week in the dark for the hue to fade again), a game which is an occasional staple of mineralogy demonstrations.

Before 1991 only small crystals were known, and cuttable material now comes from Canada, Afghanistan and Burma. The variety was named after a Finnish geologist after its discovery in Greenland in 1896. With a Mohs hardness of 5.5-6, it is just about suitable for jewellery use. the specimen is from the Lapis mines of Badakhshan (see http://on.fb.me/1KmBzjI),.

Loz

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https://bit.ly/2Izvp6W https://bit.ly/2uNMjwR https://bit.ly/2GDhH2E https://bit.ly/2uQ3YE5 https://bit.ly/2H0uoHZ http://www.jtv.com/library/hackmanite-facts.html http://www.gemologyonline.com/hackmanite.html http://www.mindat.org/min-1789.html More on tenebrescence: http://bit.ly/1N3RDsj http://bit.ly/1MxlTi4 http://bit.ly/1T9JAiS http://bit.ly/1N8FGWE

Waves at sunset This image was taken on Lake Kariba in Zimbabwe. The lake is the largest human-made lake in the world (by volume). It shows, quite simply, sunlight reflecting off the small waves in the lake. Due to the angle between the sun, lake surface, and camera, the waves appear tinted gold. -JBB... Image credit: Amodiovalerio Verde http://www.flickr.com/photos/amodiovalerioverde/245848695/ Shared under creative commons licenseSee More