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Julie

Gtplot - no Na + K

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Hi there,

I am attempting to plot a sea water analysis on a Piper diagram using Spec8. Each time I run Spec8 the ouput plots (in Gtplot) as "Na + K" = 0 and likewise that "HCO3 + CO3" = 0. I've run the same data through REACT and get the same result in Gtplot. Below is the sea water analysis I'm using and attached is a pdf of the Gtplot output. Can anyone please advise as to what I may be doing wrong?

Thanks

Julie

Species Weight Concentration

Al+++ mg/l 0.001

H3BO3 mg/l 25.5

Ba++ mg/l 0.021

Br- mg/l 67.3

CO3-- mg/l 28.0

Ca++ mg/l 411

Cd++ mg/l 0.00011

Cl- mg/l 19400

Cu++ mg/l 0.0009

F- mg/l 13

Fe++ mg/l 0.0034

H+ pH 8

K+ mg/l 392

Li+ mg/l 0.17

Mg++ mg/l 1290

Mn++ mg/l 0.0004

NO3- mg/l 68.6

Na+ mg/l 10800

O2(aq) mg/l 1766000.0

PO4--- mg/l 0.3

Pb++ mg/l 0.00003

SO4-- mg/l 2708.32

H4SiO4 mg/l 9.9

Sr++ mg/l 8.1

Zn++ mg/l 0.005

Piper diag - Seawater.pdf

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Hi there,

I am attempting to plot a sea water analysis on a Piper diagram using Spec8. Each time I run Spec8 the ouput plots (in Gtplot) as "Na + K" = 0 and likewise that "HCO3 + CO3" = 0. I've run the same data through REACT and get the same result in Gtplot. Below is the sea water analysis I'm using and attached is a pdf of the Gtplot output. Can anyone please advise as to what I may be doing wrong?

Thanks

Julie

Hi Julie:

What version of GWB and thermo database are you using?

Would you mind attaching the SpecE8 script to save me the data input work?

Regards,

Tom Meuzelaar

RockWare, Inc.

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Hi Tom,

I'm using version 7 of GWB, release 7.0.6 of SpecE8 and the thermo_phreeqc database. I've attached the script. Having had another look at the Piper diagram, I think the problem I'm encountering is that HCO3+CO3 is not plotting on two of the three graphs that make up the diagram. I think Na+K is plotting ok.

I ran the same data through GtPlot using the "Get scatter data" function and used the heading "Carbonate alkalinity" in the text file. That seems to have worked, although I would still like to be able to produce a Piper diagram directly from SpecE8.

One other question Tom regarding GtPlot. I'm wanting to plot multiple samples, label them by sample number and include a legend. How do I do that?

Thank you!

Julie

Hi Julie:

What version of GWB and thermo database are you using?

Would you mind attaching the SpecE8 script to save me the data input work?

Regards,

Tom Meuzelaar

RockWare, Inc.

Phr Seawater.sp8

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Hi Tom,

I'm using version 7 of GWB, release 7.0.6 of SpecE8 and the thermo_phreeqc database. I've attached the script. Having had another look at the Piper diagram, I think the problem I'm encountering is that HCO3+CO3 is not plotting on two of the three graphs that make up the diagram. I think Na+K is plotting ok.

I ran the same data through GtPlot using the "Get scatter data" function and used the heading "Carbonate alkalinity" in the text file. That seems to have worked, although I would still like to be able to produce a Piper diagram directly from SpecE8.

One other question Tom regarding GtPlot. I'm wanting to plot multiple samples, label them by sample number and include a legend. How do I do that?

Thank you!

Julie

Hi Julie:

The script as you sent it to me, does not converge, so I cannot evaluate this.

I assume the issue is with the oxygen concentration, which is set to 1,766,000 mg/L (usually, 5-8 mg/L is equilibrium with the atmosphere).

Am I using the same script you are using?

To answer your question about scatter data- have a look at the section entitled Adding Scatter Data in the Help menu of Gtplot. You can plot multiple scatter data points and assign symbols, colors and sizes to them, but labels and a legend are not possible. You'd either need to port the image out in vector format to Adobe Illustrator (or similar), or take advantage of the better scatter data and plotting options by upgrading to version 8.

Regards,

Tom

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Hi Tom,

Thank you for providing the info about GtPlot graphs.

I've adjusted the O2 in the basis to something more reasonable [fO2(g)= 0.2] and attached the script. It converges and produces a Piper diagram however HCO3+CO3 is not recognised on the diagram (i.e. it plots as zero). Any suggestions?

Thanks Tom,

Julie

Seawater.reaSeawater.rea

Hi Julie:

The script as you sent it to me, does not converge, so I cannot evaluate this.

I assume the issue is with the oxygen concentration, which is set to 1,766,000 mg/L (usually, 5-8 mg/L is equilibrium with the atmosphere).

Am I using the same script you are using?

To answer your question about scatter data- have a look at the section entitled Adding Scatter Data in the Help menu of Gtplot. You can plot multiple scatter data points and assign symbols, colors and sizes to them, but labels and a legend are not possible. You'd either need to port the image out in vector format to Adobe Illustrator (or similar), or take advantage of the better scatter data and plotting options by upgrading to version 8.

Regards,

Tom

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Hi Tom,

Thank you for providing the info about GtPlot graphs.

I've adjusted the O2 in the basis to something more reasonable [fO2(g)= 0.2] and attached the script. It converges and produces a Piper diagram however HCO3+CO3 is not recognised on the diagram (i.e. it plots as zero). Any suggestions?

Thanks Tom,

Julie

Seawater.reaSeawater.rea

Hi Julie:

The script now converges, and I my point plots ok on the Piper diagram in Gtplot 7.0.6 - I'm not convinced that the HCO3+CO3 point is not recognized- it just appears that the combined HCO3+CO3 concentration is extremely low relative to Cl+SO4/Mg+Ca, so it essentially plots along the zero axis.

Agreed?

Regards,

Tom

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