Erta Ale

Videoclips

The activity in Erta Ale's lava lake is an excellent model for Earth's plate tectonics. The dark crust can be seen as modelling Earth's lithosphere, the fluid lava below the asthenosphere. However, the lake has only one type of crust, so it usually only models interactions of oceanic with oceanic or continentl with continental crust. Compareable process in plate tectonics are marked like this text.

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Time lapse of the whole lava lake at dusk (44 minutes real time). In the middle of the film the lake switches from one mode of «plate» motion to a completely different one (2.9 MB). Seafloor spreading, transform faults, subduction, hot spots
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A «young» fountain producing great lava bubbles. At the end the camera zooms out to put the fountain into context with the large, otherwise undisturbed lake surface (3.4 MB). Hot spot
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A well developed, «mature» fountain in full sunlight (2.9 MB). Hot spot
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This lava fountain moves towards the camera, «eating» its way into stationary crust. Cracks open dark lava crust gets pulled into the fountain (2.4 MB). Subduction of a small plate, volcanism along subduction zone
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Fountaining along pit wall; the overhanging shore deflects the fountains away from the wall. A piece of lake crust sinks towards the fountain. Video taken at night (1.5 MB). Subduction of oceanic under continental crust (pit wall)
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First one crustal section gets thrusted over another one. As soon as a break occurs, crust sections sink into the lake due to their lower temperature and, therefore, higher density (1.2 MB). Slab pull at subduction zones
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Nighttime wide angle of large and small fountain; zoom to larger one. As the fountain creats a hole, crust sinks into the lake getting pulled under faster and faster due to its higher density (3.0 MB). Hot spots. However, hot spots on Earth do not create crustal subduction.
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Faulting and thrusting of crustal sections while being moved towards each other; on the top a small fountain is erupting (0.8 MB). Transform faults first on the bottom left, then also in the middle.
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Two similar, but independent fountains; wide angle view to indicate the relative size of lava lake and fountains. The video is «underexposed» to emphasize the fountains (0.9 MB). Hot spots
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Two lava fountains move towards each other and finally merge. The video is slightly «underexposed» to best show details within the fountains (1.7 MB). Hot spots
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Undisturbed rifting of three section sof lake crust. Note unequal rates: The lower rift opens much faster than the one on the upper left (0.8 MB). Seafloor spreading, e.g. joints between Pacific, Nazca and Cocos plate
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Emergence and sudden bursting of gas bubble. Similar bubbles often appeared in roughly the same spot and did not develop into a fountain (0.8 MB).
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One section of lake crust (above) moves past another, stationary one (below). Between them some crust gets rolled into a «snail» (0.3 MB). Upper left: Transform fault (no analogy for the «snail»)
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Folding at the front of a section of crust which is pushed against some other, stationary section (1.0 MB). Folding in collision zone between two continental plates (Himalayas, Alps)
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Time lapse of the whole lava lake (38 mins. real time) during time of high activity: many fountains and crustal motion in the entire lake (2.5 MB). Seafloor spreading, transform faults, subduction, hot spots
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Time lapse of the whole lava lake (57 mins. real time) during time of low activity: few fountains and crustal motion only in parts of the lake (3.8 MB). Seafloor spreading, transform faults, subduction, hot spots
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Time lapse of the whole lava lake (1 hour real time) during time of variable activity. Remarkably most plate spreading takes place on the left (4.1 MB). Seafloor spreading, transform faults, subduction, hot spots
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Time lapse of a section of the lava lake (1 hour real time). Note the highly variable speed and even direction of «plate» movements (4.1 MB). Seafloor spreading, transform faults, subduction, hot spots
Copyright: J. Alean, R. Carniel, M. Fulle.