Spain’s “Grand Canyon” and Nejar caves
These animals, extinct relatives of starfish and sea urchins somewhat resembling sea anemones that nearly disappeared in the Cretaceous Tertiary mass extinction were once the dominant filter feeders of Mesozoic shallow seas. We discussed them in a post before, available athttp://tinyurl.com/nnap5t9, but used a photo of the more common stem sections as illustration. Here is an image of one of their filter feeding heads, looking like something out of a horror flick.
Image credit: Cobalt 123
Wave ripples from the Silurian… 440 million years ago!
Incredible! And from these we can tell the current direction from the water flows here at that time. #geology #rocks #palaeontology #structural #ripples #waves #ocean #stones #trace
Waterton lake eclipse
Recorded on April 15th, this total lunar eclipse sequence looks south down icy Waterton Lake from the Waterton Lakes National Park in Alberta, Canada, planet Earth. The most distant horizon includes peaks in Glacier National Park, USA. An exposure every 10 minutes captured the Moon’s position and eclipse phase, as it arced, left to right, above the rugged skyline and Waterton town lights. In fact, the sequence effectively measures the roughly 80 minute duration of the total phase of the eclipse. Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit ofdigital clocks and cameras. Still, using geometry, he devised a simple and impressively accurate way to calculate the Moon’s distance, in terms of the radius of planet Earth, from the eclipse duration. This modern eclipse sequence also tracks the successive positions of Mars, above and right of the Moon, bright star Spica next to the reddened lunar disk, and Saturn to the left and below.
Image credit & copyright: Yuichi Takasaka / TWAN / www.blue-moon.ca
When streams emerge from mountains, they often spread out and deposit sediment in a distinctive pattern known as an alluvial fan.
Alluvial fans in arid areas are often used for agriculture because they are relatively flat and provide groundwater for irrigation, like this one in Kazakhstan’s Almaty province.
Read more here
Onlookers watch San Francisco’s Chinatown burn after the 1906 earthquake [948x1422]
This is one part of the rim of the caldera of Aniakchak, a 3700 year old volcanic caldera in the Aleutian islands of Alaska. The caldera formed after a large eruption emptied the magma chamber beneath, allowing the mountain to collapse downward into the empty space. The caldera is about 10 kilometers across and a kilometer deep, and as shown by the newly-grown volcanic peak inside the caldera, the mountain has been active since the major eruption.
Aniakchak volcano is part of the remote Aniakchak National Monument and Preserve, one of the most remote locations in the entire U.S. National Park Service.
dionys moser photographs the alien like landscape of the ethiopian dallol hydrothermal field, a vast area of uplifted thick salt deposits affected by intense fumarolic activity, famous for being the only known volcanic area bellow sea level and for being both the hottest place on the planet, with average annual temperatures well above 30 degrees celsius, and the most colourful, with its pools of a hot sulfuric acid brine and ferrous multicolored salt deposits.