Author Topic: Calculating potential temperatures in pMELTS  (Read 569206 times)


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Calculating potential temperatures in pMELTS
« on: August 16, 2008, 12:15:37 pm »

Is there an specific way to calculate a potential temperature in pMELTS?  I've looked through all the documentation and references for it I can find, but I can't find anything.  The definition I'm familiar with has to do with the temperature a packet of mantle (in this case) would have if it were to rise isentropically (and reversibly) from a starting P-T condition to 1 atm without experiencing any melting.  I believe this comes from work by McKenzie, but I could be mistaken.  Regardless, this seems problematic for pMELTS as it's minimum pressure is 1 GPa.  Is there a way around this?  Using option 9 to suppress liquid is the obvious (and I believe intended) method for doing this type of calculation, except for the pressure bit.

Cheers!  And thanks for all the help.


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Re: Calculating potential temperatures in pMELTS
« Reply #1 on: August 17, 2008, 11:35:46 pm »
Hi Jacob,

Normally you shouldn't run pMELTS below 1 GPa as that is the lower limit of the liquid calibration.  The solids, however, are the same in MELTS and pMELTS and are calibrated down to 1 atm.  For the special case where liquid is suppressed, it is alright to run Adiabat_1ph in pMELTS mode to 1 atm.  So you can use the method alluded to in the documentation for calculating the potential temperature.