Humans Causing California's Mountains To Grow

New submitter Megan Sever writes: "This is a cool story about anthropogenic effects of water withdrawal moving mountains — literally. According to new research published today (abstract) and reported in EARTH Magazine, humans have been causing the Sierra Nevada mountains to rise. By withdrawing water for irrigation and other purposes, we have inadvertently removed water from the mountains, allowing them to uplift. The research shows a seasonal and annual cycle."

Comments

I know it's just the one.

[Impy the Impiuos Imp]

I thought Grand Tetons only swelled when you add liquid to them.

Re:I know it's just the one.

[frank_adrian314159]

Yeah. And don't feed them after midnight.

Re:Tectonics?

[Anonymous Coward]

I'm certain that plate tectonics have absolutely nothing to do with the rise in the mountains.

Are you trying to dispute an article you clearly haven't read?

Re:Landfills too

[FatdogHaiku]

Bah, we've been building "mountains" for quite a while already.

Yes, but no one is talking about the looming molehill shortage!

Re:How do they know man's actions cause this?

[Layzej]

Unpublished? It's published right here: http://www.nature.com/nature/j...

So what data are they using to compare to the current data to determine this is caused by man's actions?

They looked at seasonal variations. If seasonal variations are causing a change in elevation, why wouldn't the volume of groundwater lost over the past century and a half also cause a change in elevation? In fact, when they compared the expected changes in elevation with the observed changes they got a pretty good match.

Like isostasy

[PeterM from Berkeley]

This reminds me of isostasy http://en.wikipedia.org/wiki/Isostasy/ --as mountains erode, they rise again due to the buoyancy of the rock underneath them floating upon the magma below.

Pull out the mass of the water, and up go the mountains.

--PeterM

Re:How do they know man's actions cause this?

[TapeCutter]

It may sound natural to you but what you are suggesting sounds like magic to me - spend a century or more removing billions of tons of underground water and nothing changes, not even slightly? The research is published in Nature, you know what to do if you think they are wrong, right?

Re:How do they know man's actions cause this?

[Layzej]

As the snow accumulates in the winter the mountain compresses. As it melts in the summer it rises. That is what they found when they measured it. It is a surprising result, and may make your head hurt, but it is what they found.

Re:How do they know man's actions cause this?

[Anonymous Coward]

So did you even try to read the article or are you a moron? You've been posting for a while here, and it's easy to draw the conclusion that you decided what you want to be true before you read it. You even state that you have seen they take into account the natural effects. Sounds like you're a moron to me, and haven't bothered to RTFA. The other thing is that you are talking about something about which you know nothing. You claim to understand yet call thing "unpublished" despite it appearing in Nature. This is another example of an armchair fuckwit jumping to conclusions rather than actually paying attention to what is being said. Your post does say the word "controversial" but what it obvious is that you're just plain stupid.

Re:GPS seasonal variations...duuh

[Layzej]

Why, so they could find out that although it was supposed that hydrologyinduced stresses may be the cause, no one had yet shown it? They might have then performed the very experiment that they did in order to test the hypothesis? But why do you assume they weren't aware of the previous literature?

Salton Sea Water Level effects San Andreas Fault

[Required Snark]

Historically, the Salon Sea in inland Southern California has long term wet and dry periods. When it is filled with water there tend to be earthquakes in the region of the San Andreas Fault that run through the Salton Sea area. When it is dry there tends to be a much longer period between major quake in this part of the fault.

http://en.wikipedia.org/wiki/Salton_Sea#Earthquake_geology

The Salton Sea and surrounding basin sits over the San Andreas Fault, San Jacinto Fault, Imperial Fault Zone, and a "stepover fault" shear zone system. Geologists have determined that previous flooding episodes from the Colorado River have been linked to earthquakes along the San Andreas Fault. Sonar and other instruments were used to map the Salton Sea's underwater faults during the study. During the period when the basin was filled by Lake Cahuilla, a much larger inland sea, earthquakes higher than magnitude 7 occurred roughly every 180 years, the last one occurring within decades of the year 1700. Computer models suggest the normal faults in the area are most vulnerable to deviatoric stress loading by filling in of water. Currently, a risk still exists for an earthquake of magnitude 7 or 8. Simulations also showed, in the Los Angeles area, shaking and thus damage would be more severe for a San Andreas earthquake that propagated along the fault from the south, rather than from the north. Such an earthquake also raises the risk for soil liquefaction in the Imperial Valley region.

After the last flood from the Colorado River into the Salton Sea after 1900, a series of dams were built to keep the river from flowing into California. Since then there are been no really large magnitude earthquakes from the San Andreas in Southern California.

It seems extremely likely that human activity has altered the earthquake pattern. This means it is possible that removing large amounts of ground water from the San Joaquin Valley could measurably effect the height of the Sierra Nevada mountains.

Re:I wouldn't trust a GPS in the milimetric range

[Layzej]

You are better off with science. Your gut will betray you. If you are interested you should read:

Bar-Sever, Y. E., Kroger, P. M. & Borjesson, J. A. Estimating horizontal gradients of tropospheric path delay with a single GPS receiver. J. Geophys. Res. 103, 5019–5035 (1998)

Blewitt, G. Carrier phase ambiguity resolution for the Global Positioning System applied to geodetic baselines up to 2000 km. J. Geophys. Res. 94, 10187–10283 (1989)

Bertiger, W. et al. Single receiver phase ambiguity resolution with GPS data. J. Geod. 84, 327–337 (2010) Rebischung, P. et al. IGS08: The IGS realization of ITRF2008. GPS Solut. 16, 483–494 (2012)

and of course Amos, C. et al. Uplift and seismicity driven by groundwater depletion in central California. Nature doi:10.1038/nature13275 (2014)