Groundbreaking discovery finally proves rain can move mountains
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Re: Groundbreaking discovery finally proves rain can move mountains
#2Study of Himalayan erosion.
"When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hillslopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landscape has been eroding," Dr. Adams said.
Re: Groundbreaking discovery finally proves rain can move mountains
#3The paper Climate controls on erosion in tectonically active landscapes [1]:
> The ongoing debate about the nature of coupling between climate and tectonics in mountain ranges derives, in part, from an imperfect understanding of how topography, climate, erosion, and rock uplift are interrelated. Here, we demonstrate that erosion rate is nonlinearly related to fluvial relief with a proportionality set by mean annual rainfall.
Re: Groundbreaking discovery finally proves rain can move mountains
#4Study of Himalayan erosion. "When a cosmic particle from outer space reaches Earth, it is likely to hit sand grains on hillslopes as they are transported toward rivers. When this happens, some atoms within each grain of sand can transform into a rare element. By counting how many atoms of this element are present in a bag of sand, we can calculate how long the sand has been there, and therefore how quickly the landsc…
He's referring to beryllium-10, which is mostly generated by cosmic ray interactions with nitrogen and oxygen in the atmosphere. The Be-10 subsequently washes out of the atmosphere with precipitation and tends to bind in surface soils. It has a half life of 1.39 million years so it is useful for dating various geological phenomena.
https://en.wikipedia.org/wiki/Beryllium-10
You can see how this beryllium isotope was used in the original paper "Climate controls on erosion in tectonically active landscapes" (linked by sradman in comment https://news.ycombinator.com/item?id=24812181) within the Materials and Methods section of the paper.
Re: Groundbreaking discovery finally proves rain can move mountains
#5"Earthshattering" would be a better word
Re: Groundbreaking discovery finally proves rain can move mountains
#6"...scientists have also believed rain can erode a landscape quickly enough to essentially 'suck' the rocks out of the Earth, effectively pulling mountains up very quickly."
I do not understand this, unless the point is that rainfall, by eroding valleys, reduces the weight of a mountain range, allowing tectonic forces to raise the ridges and peaks faster than otherwise.
Re: Groundbreaking discovery finally proves rain can move mountains
#7"...scientists have also believed rain can erode a landscape quickly enough to essentially 'suck' the rocks out of the Earth, effectively pulling mountains up very quickly." I do not understand this, unless the point is that rainfall, by eroding valleys, reduces the weight of a mountain range, allowing tectonic forces to raise the ridges and peaks faster than otherwise.
I'm confused as well. Another possibility is the "up" is relative? If there is a mountain already buried in looser soils, rain could wash away and expose the mountain, which will appear to be going up, because everything else is going down.
Re: Groundbreaking discovery finally proves rain can move mountains
#8"...scientists have also believed rain can erode a landscape quickly enough to essentially 'suck' the rocks out of the Earth, effectively pulling mountains up very quickly." I do not understand this, unless the point is that rainfall, by eroding valleys, reduces the weight of a mountain range, allowing tectonic forces to raise the ridges and peaks faster than otherwise.
I'm confused as well. Another possibility is the "up" is relative? If there is a mountain already buried in looser soils, rain could wash away and expose the mountain, which will appear to be going up, because everything else is going down.
Crust floats on the mantle. Mountains are areas where the crust is thick and it goes down into the mantle further than less thick areas. As the weight from the top is removed, that can push up areas from down below.
We tend to think of mountains as stable things with the constant stress underneath, rather than a layer of congealed fat on top of a warm stove (or, a lava lamp). But the latter is a better model for geologic behaviour over long periods of time.
Re: Groundbreaking discovery finally proves rain can move mountains
#9"Earthshattering" would be a better word
Groundbreaking works too :)
Re: Groundbreaking discovery finally proves rain can move mountains
#10Earlier quoted context omitted.
I'm confused as well. Another possibility is the "up" is relative? If there is a mountain already buried in looser soils, rain could wash away and expose the mountain, which will appear to be going up, because everything else is going down.
Crust floats on the mantle. Mountains are areas where the crust is thick and it goes down into the mantle further than less thick areas. As the weight from the top is removed, that can push up areas from down below. We tend to think of mountains as stable things with the constant stress underneath, rather than a layer of congealed fat on top of a warm stove (or, a lava lamp). But the latter is a better model for geol…
This is correct. The earth is ductile at long time periods, and mountains maintain isostatic equilibrium as the tops are eroded away. The article quote is absurd. Source: my earth science PhD.