It’s Not Dead, Jim

It might not be, anyway.

Scientists are musing that the Martian shield volcanoes might be dormant, not dead. On Earth, continental drift will shift the eruption spot of a volcano. We see this in the Hawaiian Islands: the crust of that part of the Pacific Ocean is moving northwest, so as one travels southeast on the surface, the landforms are more recent. Indeed, only the Big Island has active volcanoes today.

The Mars Express orbiter has uncovered evidence that the most recent deposits on Ascraeus Mons might be just a few million years old. The thinking is that the subcrustal hot spot might itself be drifting. The conventional wisdom today is that continental drift requires the lubrication of oceans of water. Mars doesn’t seem to have drift; its crust appears to be in one piece.

Of course, the crust itself could be slowly moving over a liquid interior layer. I don’t think that has been definitively ruled out. It’s just not in the model we have. We think that’s what’s going on at Jupiter’s moon Europa: a thin ice crust floating above a liquid ocean. That water in turn covers a “bedrock” another several dozen miles below the bottom of the ice.

About these ads

About catholicsensibility

Todd and his family live in Ames, Iowa. He serves a Catholic parish of both Iowa State students and town residents.
This entry was posted in Astronomy. Bookmark the permalink.

One Response to It’s Not Dead, Jim

  1. Dale Price says:

    So, maybe, that’s where the water went? Hmm. That would/could jibe with the plume that was recently found indicating that water periodically seeps up.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s