Wednesday, February 10, 2010

Brief review of 5 sources part I

Titan: What we've learned about a strange new world, by Michael Carroll, Astronomy Magazine, March 2010

In the region called Hotei Arcus, of the Xandau plateau-like region on Titan, there are multiple features that look like volcanoes. Instruments on the Cassini spacecraft are seeing brightness in two regions and possible flow morphology that could represent cyrovolcanic flows according to Rosaly Lopes a scientists that works at the Jet Propulsion Lab. Channel features have also be found on the surface of Titan that resemble lava flows in radar and some also originate from what could be a caldera.

Volcanic Worlds: Exploring the Solar System''s Volcanoes, edited by Rosaly Lopes and Tracy Gregg

This book is actually a compilation of volcanism articles. I haven't finished the book yet. I have read one article about Earth's volcanic, an article on Venus and I am in the middle of an article on the Moon.

The first article was entitled Volcanoes on Earth: Our basis for understanding volcanism by Katherine Cashman. The article discussed hot spot volcanism of the Hawaiian Islands and subduction zone volcanism and the different features and lavas associated with each.

The second article was entitled Earth's evil twin: The volcanic world of Venus by Ellen Stofan. On Venus there are cone and shield volcanoes, shield volcanoes out number the cone volcanoes. Venus has steep-sided features that are also called pancake domes with flat-tops. Radar indicates brightness of a lava. The brighter lavas indicated rough formation while darker lavas indicate smooth flow. Most Venusian volcanoes tend to resemble hot spot formations like that of the Hawaiian Islands. Venus also has a large number of flood plains with rough and smooth flows that have flowed for great distances. Flow channels have also be spotted on Venus that are kilometers wide and hundreds of kilometers long. Water has not existed on Venus for billions of years if ever mainly due to the heat from the closeness of the Sun and the runway greenhouse effect so the channels couldn't have been formed by water.

Icy Worlds of the Solar System, edited by Pat Dasch


The Voyager probe flew by Triton, the largest moon of Neptune, in 1989 and discovered plume of dark material rising about 8 kilometers above the surface and the probe observed very few impact craters signaling that the surface was relatively young. Scientists believe the plumes might be triggered by some sort of source internally. The volcanism on Triton provides evidence that there is melting in the interior. After reading about Triton in this book it seems to be saying indirectly that the source of Triton's heat may have been from a collision with another planetary body millions of years ago.

3 comments:

  1. Do you know how many planets/moons (other than earth) in our solar system have been found with active volcanoes?

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  2. Planet-wise
    Mars was active volcanic wise, but not now.
    Venus was and scientists believe still might be to get better information we need to send a probe.

    Moon-wise
    Jupiter's four largest moons have activity. Ganymede and Callisto scientist are just starting research on. They do not have volcanoes but may have some sort of volcanic process going on. Europa is constantly having fissures form and some sort of liquid is coming through and covering the surface. Io does have active volcanoes that are erupting w/ sulfuric acid.

    Saturn's has 2 moons. Enceladus has plume/geyers of water vapor. Titan is believed to have cryovolcanism.

    Neptune's largest moon Triton is believed to have geysers of liquid nitrogen.

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  3. Have rift valleys ever been observed on any of these volcanically active moons? I suppose it would be possible that only hotspot type activity is causing the volcanism there, in which case...is there any literature out there on the relationship between the abundance of water here on Earth and tectonism -- in regards to its isostatic effect? Glaciation pushes continental cratons into the mantle -- parts of the interiors of Antartica and Greenland are even below sealevel. It seems to me that the effects of this volume change in the mantle as well as the thermodynamics is atleast worth looking at for geophysicists.

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