Mark S. Ghiorso

Mark S. Ghiorso (born October 21, 1954) is an American geochemist who resides in Seattle, Washington. He is best known for creating MELTS, a software tool for thermodynamic modeling of phase equilibria in magmatic systems.[4]

Mark S. Ghiorso
Born(1954-10-21)October 21, 1954[1]
San Francisco, California[1]
CitizenshipAmerican
EducationUniversity of California Berkeley
Known formodeling phase equilibria in magmatic systems
Scientific career
Fieldsgeochemistry
InstitutionsOFM Research, University of Washington, Vanderbilt University[2]
Doctoral advisorIan Carmichael
InfluencesHal Hegelson, Ian Carmichael, Richard Sack, Bernard Evans[3]
Websitemarkghiorso.org

Education

Ghiorso earned an AB, MS, and PhD from the University of California, Berkeley. He chose Berkeley for practical reasons: "I went to Berkeley because it was the local school, because tuition was essentially free, and because I was fascinated as a high school student with hot springs, volcanos, and, in particular, the work of Howell Williams and Arthur L. Day."[5]

Career

In 1980, Ghiorso was hired by the University of Washington (UW) as assistant professor in the Department of Geological Sciences.[1] He was promoted to associate professor (a tenured position) three years later and to full professor in 1986. He served as department chair from 1994 to 1999.

In 2003, he was hired by the University of Chicago. Leaving the UW was a difficult decision, as Ghiorso is a great believer in public education. He cited serious concerns about the UW administration as a primary reason for departing.

In 2005 he decided to leave academia and dedicate himself full-time to research. He returned to Seattle and, with his colleague Richard Sack, founded the small non-profit research company OFM Research, where he is Vice President and Senior Research Scientist.[6][1] He also holds affiliate faculty appointments at the University of Washington and Vanderbilt University.[7][8]

Ghiorso has also served as Associate Editor for the following scientific journals: American Journal of Science (1990–present); American Mineralogist (1990–1993); Geochimica et Cosmochimica Acta (1991–1993); and Contributions to Mineralogy and Petrology (2015–present),

Scientific contributions

As an undergraduate, Ghiorso wrote an honors thesis on the hot springs in the Devil's Kitchen area of Lassen Volcanic Park. This work was never published.[9] During his graduate work he continued to do experimental work related to acid sulfate hot springs until he became interested in attempts by Ian Carmichael to create a model for solutions in silicate liquids that could be used as a geothermometer for igneous rocks.[9]

Background

In igneous petrology, geologists attempt to learn more about volcanic systems through the record in igneous rocks. Most magma is generated in the mantle through a process called decompression melting. As material rises and the pressure decreases, solidus declines until part of the mantle can melt.[10] At or near the surface, the magma cools and crystallizes. Depending on the conditions, it may have time to cool uniformly, or fractional crystallization can occur if parts of the magma are removed after they crystallize.[11]

Bowen's reaction series

An early model for fractional crystallization, which explained why certain types of mineral tend to be found together in igneous rocks, was Bowen's reaction series, formulated in 1922. Bowen found that, as magma crystallizes, it separates into two series: a continuous series of minerals that continuously adjusts their composition through interactions with the melt, and a discontinuous series of minerals that remain fixed in composition as they cool. Thus, the type of mineral indicates the temperature at which it was formed.[12]:297[13]:89–91

Until the 1960s, interpretation of the igneous rock record was largely qualitative. Ian Carmichael wanted to determine quantitative information such as the temperature and pressure of the magma when crystals were formed as well as dissolved water and oxygen content.[14] For this, thermodynamic models were needed. Although attempts to apply rigorous thermodynamics to igneous processes go back to at least 1949, they were hindered by a lack of experimental data.[15] Using tools such as a drop calorimeter and wet chemistry, Carmichael and colleagues set out to systematically explore thermodynamic properties of magma at high temperatures.[14]

Thermodynamic models

Ghiorso began working with Carmichael on silicate-liquid models in 1978, and in 1980 they published their first geothermometers.[16] Carmichael hired Richard Sack in 1980, and Sack began extensive experiments that went into a more sophisticated model that was published in 1983, when Ghiorso was at the University of Washington. Ghiorso wrote a program in FORTRAN 77 that he distributed to other researchers.[16] Ghiorso and Sack realized, however, that the model needed to become more sophisticated.

At first, NSF program managers were skeptical of this computational approach, and Ghiorso had three NSF proposals turned down.[9] Fortunately, he managed to persuade the Digital Equipment Corporation to fund his work.[16] After a decade of publishing thermodynamic data on minerals such as olivine and feldspar, Ghiorso and Sack presented their new model, now called MELTS. Their 1995 publication in Contributions to Mineralogy and Petrology became the journal's most cited paper, with more than 2,100 citations as of early 2017.[17]

After the publication of MELTS, Ghiorso continued to improve and extend it with the help of colleagues such as Mark Hirschmann, Paul Asimow, Pete Reiners and Victor Kress. After they identified some fundamental problems with the theory at high pressure, they developed pMELTS, a model for high pressures (1-3 gigapascals (GPa)), and published it in 2001.[16] Asimow and co-authors published phMELTS, a model for mid-ocean ridge basalts that incorporated the effect of water content.[18] In 1998, Ghiorso, Hirschmann and Tim Grove established the Library of Experimental Phase Relations (LEPR), an online database for experimental results on solid-melt equilibria.[16][19] With Guilherme (Guil) Gualda, he modified MELTS to work better with rhyolite, a silicate-rich series of rocks, and released rhyolite-MELTS.[16]

Ghiorso is the lead investigator on an NSF collaborative research grant to develop ENKI (Enabling Knowledge Integration), a Web-based model-configuration and testing portal for computational thermodynamics and fluid dynamics. He is the lead principle investigator on the project.[20] With Dmitri Sverjensky of Johns Hopkins University, Ghiorso is leading a Deep Carbon Observatory project to integrate MELTS with the Deep Earth Water Model (DEW) created by Sverjensky.[21] The DEW program models water-rock interactions to depths of 200 km.[22] The movement of carbon between silicate melts and aqueous fluids is still poorly understood.[21]

Awards

In 1984, while Ghiorso was at the University of Washington, he received a Presidential Young Investigator Award, a research grant for an amount of $245,918, from the National Science Foundation.[23] For a paper published in Computers & Geosciences,[24] he received the Best Paper Award from its publisher, the International Association for Mathematical Geosciences.[25] He was elected Fellow of the Mineralogical Society of America in 1993, the Geological Society of America in 1997, and the American Geophysical Union in 1999. The Mineralogical Society of America made him a Distinguished Lecturer for 1996–1997, elected him Councilor for 1997–2001, and awarded him the Dana Medal in 2003.[9] He received the Bunsen Medal from the European Geosciences Union in 2010 and the Norman L. Bowen Award from the VGP Section of the American Geophysical Union in 2014.[4][5][1]

Works

Ghiorso has published 115 peer-reviewed papers for a total of 7289 citations and an h-index of 41. Some of the most highly cited papers follow:[26]

  • Sack, R. O.; Carmichael, I. S. E.; Rivers, M.; Ghiorso, M. S. (February 1981). "Ferric-ferrous equilibria in natural silicate liquids at 1 bar". Contributions to Mineralogy and Petrology. 75 (4): 369–376. Bibcode:1981CoMP...75..369S. doi:10.1007/BF00374720.
  • Sack, Richard O; Ghiorso, Mark S (1991). "Chromian spinels as petrogenetic indicators: Thermodynamics and petrological applications". The American Mineralogist. 76 (5–6): 827–847.
  • Ghiorso, Mark S.; Sack, O. (October 1991). "Fe-Ti oxide geothermometry: thermodynamic formulation and the estimation of intensive variables in silicic magmas". Contributions to Mineralogy and Petrology. 108 (4): 485–510. Bibcode:1991CoMP..108..485G. doi:10.1007/BF00303452.
  • Ghiorso, Mark S.; Sack, Richard O. (March 1995). "Chemical mass transfer in magmatic processes IV. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures". Contributions to Mineralogy and Petrology. 119 (2–3): 197–212. Bibcode:1995CoMP..119..197G. doi:10.1007/BF00307281.
  • Baker, M. B.; Hirschmann, M. M.; Ghiorso, M.S.; Stolper, E. M. (25 May 1995). "Compositions of near-solidus peridotite melts from experiments andthermodynamic calculations". Nature. 375 (6529): 308–311. Bibcode:1995Natur.375..308B. doi:10.1038/375308a0.
  • Asimow, Paul D.; Ghiorso, Mark S. (1 October 1998). "Algorithmic modifications extending MELTS to calculate subsolidus phase relations". American Mineralogist. 83 (9–10): 1127–1132. Bibcode:1998AmMin..83.1127A. doi:10.2138/am-1998-9-1022.
  • Ghiorso, Mark S.; Hirschmann, Marc M.; Reiners, Peter W.; Kress, Victor C. (May 2002). "The pMELTS: A revision of MELTS for improved calculation of phase relations and major element partitioning related to partial melting of the mantle to 3 GPa". Geochemistry, Geophysics, Geosystems. 3 (5): 1030. Bibcode:2002GGG.....3.1030G. doi:10.1029/2001GC000217.

Software tools that Ghiorso has created, either alone or with others, include the following:

  • MELTS, pMELTS, and thermodynamic properties calculators[2]
  • CTserver: web services for computational thermodynamics of geological materials[27]
  • LEPR, a database portal for experimental data on mineral-melt equilibria[19]
  • PhasePlot, software to visualize phase equilibria on pressure-temperature grids.[28]
  • MagmaSat (Mac) and MagmaSatApp (iPad), software to compute saturation conditions of H2O-CO2 mixed fluids in natural composition silicate melts[29][30]

References
  1. "Curriculum Vitae : Mark S. Ghiorso" (PDF). Markghiorso.org. Retrieved 2017-05-03.
  2. "Welcome to MELTS". Melts.ofm-research.org. Retrieved 2017-05-03.
  3. Ghiorso, Mark S. (2004). "Acceptance of the Dana Medal of the Mineral Society of America for 2003". American Mineralogist. 89: 910–911. Retrieved 23 August 2017.
  4. "Robert Wilhelm Bunsen Medal 2010: Mark S. Ghiorso". Awards & Medals. European Geophysics Union. Retrieved 2017-05-03.
  5. AGU (20 April 2015). "Ghiorso and Sack receive 2014 Norman L. Bowen AwardAGU". EOS. 96. doi:10.1029/2015EO028095.
  6. "Welcome to OFM Research". OFM Research Inc. Retrieved 25 August 2017.
  7. "Directory Profile - Earth and Space Sciences". Ess.washington.edu. Retrieved 2017-05-03.
  8. "Earth and Environmental Science | Vanderbilt University". Vanderbilt.edu. Retrieved 2017-05-03.
  9. Carmichael, Ian (2004). "Presentation of the Mineralogical Society of America Dana Medal for 2003 to Mark S. Ghiorso" (PDF). American Mineralogist. 89: 909. Retrieved 23 August 2017.
  10. Brown, Edited by Geoff; Hawkesworth, Chris; Wilson, Chris (1992). Understanding the earth : A new synthesis (2nd ed.). Cambridge, England: Cambridge University Press. pp. 92–93. ISBN 9780521427401.CS1 maint: extra text: authors list (link)
  11. Wilson, Marjorie (1993). Igneous petrogenesis (Reprint ed.). London: Chapman & Hall. p. 82. ISBN 9780412533105.
  12. Young, Davis A. (2003). Mind over magma : the story of igneous petrology. Princeton, N.J.: Princeton University Press. ISBN 9780691102795.
  13. Monroe, James S.; Wicander, Reed (2011). The Changing Earth: Exploring Geology and Evolution. Engage Learning. ISBN 9781133715511.
  14. Lange, Rebecca (14 February 2012). "Ian S. E. Carmichael (1930–2011)". Eos Transactions. 93 (7): 68. Bibcode:2012EOSTr..93...68L. doi:10.1029/2012EO070006.
  15. Ghiorso, Mark S. (May 1997). "Thermodynamic models of igneous processes". Annual Review of Earth and Planetary Sciences. 25 (1): 221–241. Bibcode:1997AREPS..25..221G. doi:10.1146/annurev.earth.25.1.221.
  16. "A largely factual and incomplete history of MELTS". OFM Research. Retrieved 25 August 2017.
  17. "Google Scholar Citations". Scholar.google.com. 1995-01-03. Retrieved 2017-05-03.
  18. Asimow, P. D.; Dixon, J. E.; Langmuir, C. H. (January 2004). "A hydrous melting and fractionation model for mid-ocean ridge basalts: Application to the Mid-Atlantic Ridge near the Azores" (PDF). Geochemistry, Geophysics, Geosystems. 5 (1): Q01E16. Bibcode:2004GGG.....5.1E16A. doi:10.1029/2003GC000568.
  19. Hirschmann, M. M.; Ghiorso, M. S.; Davis, F. A.; Gordon, S. M.; Mukherjee, S.; Grove, T. L.; Krawczynski, M.; Medard, E.; Till, C. B. (March 2008). "Library of Experimental Phase Relations (LEPR): A database and Web portal for experimental magmatic phase equilibria data". Geochemistry, Geophysics, Geosystems. 9 (3): n/a. Bibcode:2008GGG.....9.3011H. doi:10.1029/2007GC001894.
  20. "NSF Award Search: Award#1550482 - SI2-SSI: Collaborative Research: ENKI: Software Infrastructure that ENables Knowledge Integration for Modeling Coupled Geochemical and Geodynamical Processes". Nsf.gov. Retrieved 2017-05-03.
  21. "Models create a virtual carbon laboratory". Deep Carbon Observatory. Retrieved 22 June 2017.
  22. "Deep Earth Water Model". Deep Carbon Observatory. Retrieved 25 August 2017.
  23. "Award Abstract #8451694: Presidential Young Investigator Award". National Science Foundation. Retrieved 23 August 2017.
  24. Ghiorso, Mark S. (January 1983). "LSEQIEQ: a FORTRAN IV subroutine package for the analysis of multiple linear regression problems with possibly deficient pseudorank and linear equality and inequality constraints". Computers & Geosciences. 9 (3): 391–416. Bibcode:1983CG......9..391G. doi:10.1016/0098-3004(83)90008-0.
  25. "Computers & Geosciences - Best Paper Award (1978 – )". Awards & Honors. International Association for Mathematical Geosciences. Retrieved 23 August 2017.
  26. "Web of Science". Thomson Reuters. Retrieved 22 August 2017.
  27. "CTserver Web services". MELTS. OFM Research. Retrieved 23 August 2017.
  28. "PhasePlot Help Center". Phaseplot.org. Retrieved 2017-05-03.
  29. "MagmaSat on the Mac App Store". Itunes.apple.com. 2015-04-06. Retrieved 2017-05-03.
  30. Ghiorso, Mark S.; Gualda, Guilherme A. R. (5 June 2015). "An H2O–CO2 mixed fluid saturation model compatible with rhyolite-MELTS". Contributions to Mineralogy and Petrology. 169 (6): 53. Bibcode:2015CoMP..169...53G. doi:10.1007/s00410-015-1141-8.
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