Saturday, February 15, 2014

not very silent Saturday with Kilauea

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| Earth on Feb 04, 2012

Amazing photos from Kilauea Volcano

In December 2011, lava flows from Kilauea Volcano made a long journey from to the sea. See these great images from volcano researcher Stephen O’Meara.

In early 2012, Stephen O’Meara of Volcano Watch International sent these images of lava flow on December 24, 2011 from Kilauea Volcano, the youngest and southeastern most volcano on the Big Island of Hawaii.

He wrote:
In mid-December 2011, lava flows from Kilauea Volcano made a long journey from an inland cone to the sea. The surface flows advanced near the extreme eastern edge of the Hawaiian Volcanoes National Park boundary, requiring a roughly seven-mile hike across hardened lava to reach the flows. These images show activity along the western edge of that long and broad flow on X-Mas Eve Day.
I thought EarthSky readers might be interested in these sample photos. The wide flow field was very active along the western edge, with some small lava falls and many surface breakouts. The lava falls were on the order of six to eight feet (vertical). There were several ocean entries, with sluggish transitional and Aa lava, with cascading or rolling fragments.
Above right: A molten lava flow plunges about eight feet into a deep depression (originally about 15 feet deep) and ponds. You can see the older lava rock over which the lava flows. As the lava falls onto the surface below, the lava continues to flow (backward) into a deep cavity, called a lava tube, created many years earlier. In time, the lava will completely fill this tube, as well as the depression. As the lava descends, sections of it stretches (like mozzarella cheese) into thin strands of glass called Pele’s Hair.

Above: A lobe of molten lava (on the right) greets another lobe of molten lava (on the left) whose surface has already begun to cool. The top of a lava flow cools instantly into a silvery grey crust. The lava within stays red hot and glowing. Sunlight shining through the glassy surface creates the shiny iridescence. Different colors reflect the different densities in the “glass.”

Above: When an advancing lava flows slows and cools, its surface starts immediately to crust over. But if the pressure feeding the flow is great enough, lava can break through the cooling crust and create stunning spectacles such as this lava cascade.

Above: Dual lava flows breaking through cooling lava crust over a natural depression in the landscape. Note how the silver skin of the crust insulates the molten lava inside. Such basalt flows are usually 50 percent silica glass and have temperatures of 900-1200? C / 1650 – 2190? F.

Above: A lava cataract ~25 feet across and ~10- to 15-feet tall. As the lava streams forward its banks cool and thicken forming a natural semi-sold levee. The hot molten center of the river keeps flowing. The top of the flow is pliable, like plastic wrap. As it cools it becomes cumbrous and is pulled, squeezed, rippled, and tugged by the faster moving, hotter lava underneath.

At left: Lava flowing over a cliff starts to “back up” and cause ripple patterns – like brownie batter in a tilted pan. Depending on the temperature, composition, and speed, the lava’s supple surface can be ropey, wrinkled, or crumpled, forming beautiful patterns when hardened.
Volcano Researcher Stephen O’Meara has been scientifically studying active volcanoes for 30 years. In 1993, Stephen and Donna O’Meara founded Volcano Watch International with the goal of better understanding how Earth’s active volcanoes work and helping to save lives. All images in this post copyright Steve & Donna O’Meara /Volcano Watch International. Used with permission.

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