Friday Headlines, August 22, 2014
THE LATEST IN THE GEOSCIENCES
It’s been a couple of months… but I’m back!
A thigh bone on Mars? NO.
Drought causing uplift
Pouring lava – Cool video of the day
The Curiosity Rover took this photo the other day:
To the untrained eye, that long think in the upper center might be mistaken for a bone. To the trained eye (like mine), it’s a rock. An interesting rock, sure, but just a rock. It’s certainly not a femur (thigh bone); it’s not shaped right.
It’s shape speaks to me about the environment in which the rock formed. I see veins in the adjacent rocks. I’ll bet that’s made of vein material. Veins are interesting. Hydrothermal activity, maybe?
It’s interesting. But it’s just a rock.
Water is heavy, it turns out, and when reservoirs and aquifers run dry, the Earth’s crust becomes a little lighter.
Rock is heavy, too, you say. That’s true. The difference in weight between wet rock and dry rock is pretty subtle. But when you consider the vast amount of water that has been lost, equivalent to about 4 inches of water spread evenly over the surface of the United States west of the Rocky Mountains, the difference is not inconsequential.
The Earth’s lithosphere (the crust plus the uppermost mantle – see this post for more information) essentially floats on the deeper mantle, much like ice floats in water. If the ice (or lithosphere in this case) becomes lighter, it floats higher.
So, just how much higher are we talking about?
Not a lot. On average only 1/6 of one inch. But measurable.
This is just cool. Scientists and artists at Syracuse University collaborated to melt rock and pour it into a water bath or an ice trough, for the sake of art and of science.
Just watch. It’s cool.