NASA Earth Observatory: cool flows at Llullaillaco 29 March 2010Posted by admin in Argentina, Chile, Llullaillaco, NASA Earth Observatory, volcanoes.
Tags: Argentina, Chile, Lluillaillaco, NASA Earth Observatory
The latest image of the day at the NASA Earth Observatory is this astronaut photograph of Llullaillaco volcano, which is situated on the Argentina/Chile border. Llullaillaco is the highest historically active volcano in the world, 6739 metres high, and last erupted in the nineteenth century. The lava flow extending to the north of the volcano shows very clearly features typical of a viscous flow on a steep slope. Lava at the edges of the flow has cooled more rapidly than that in the centre to produce the walled channel effect of a flow levée, while the faster cooling of the upper surface of the lobe at the front of the flow has produced characteristic layering and pressure ridges at 90 degrees to the direction of the flow. The Earth Observatory caption refers to the lobes of this flow as coulées (but this is what I call a coulée).
It’s also interesting to note, given the time of year, that the head of the Easter Bunny is clearly visible between the two lobes of the lava flow in the top right of the image:
[Astronaut photograph ISS022-E-8285 was acquired on December 9, 2009, with a Nikon D2Xs digital camera using an 800mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 22 crew.]
Llullaillaco volcano, Argentina-Chile border – NASA Earth Observatory, 29 March 2010