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President's Letter | October 2007

head_brantley.jpg: Susan L. Brantley
Prof. Susan L. Brantley
Why Geochemists Never Agree: It’s All about the Data!
Susan L. Brantley, President of Geochemical Society


A National Science Foundation program officer once asked me: “Why can’t geochemists ever agree?”He intended this question as an indictment of our community. Compared with other kinds of scientists, we geochemists are generally more disorganized and ineffective in promoting our own field. We seem to be uniquely challenged to agree on which programs should be funded, which approaches make the most sense, and what initiatives are the most exciting.

I believe that our failure to unite our voices as geochemists has a simple origin – it is the complexity of our subject. After 2 years as President of the Geochemical Society (GS), I have come to the conclusion that the GS can address this problem by leading the synthesis of geochemical data because not only will it advance the science but it will unify the voices of geochemists. In my parting comments here, I will expand on this idea.

The most successfully organized group of earth scientists of whom I am aware are the seismologists who self-organized into IRIS (www.iris.edu). The level of unity within IRIS has led to a global network of seismometers, shared equipment for seismological deployments, and shared data online. I would argue, however, that their data are less complex than our data. Think about it: seismologists measure the amplitude of ground motion versus time at many locations. I do not mean in anyway to disparage seismology; in fact, I am envious of their ability to collect large datasets, share them, and interpret them powerfully.

In contrast, geochemists measure the chemistry of the earth’s atmosphere, hydrosphere, biosphere, and lithosphere. The chemistry of these envelopes varies from the relatively well-mixed atmosphere to the extremely poorly mixed lithosphere and biosphere. The parameters that have been measured from all these entities over the last 200 or so years can vary with space and time over a range of more than ten orders of magnitude. I propose that the reason geochemistry is so complex sociologically and scientifically is the heterogeneity implicit in the chemistry of our world.

Using a metaphor, physicists look at the framework of the earth – they look at the loom and the structure of the loom – while chemists look at the materials – the individual threads -- strung across the loom. As chemists, we love the complex beauty of this fabric, including the “threads” consisting of the 100 or so elements and the many species and isotopes per element. Furthermore, this lovely fabric is manifested as individual “cloths” that move around on the planet -- the 4500 or so minerals on earth, the untold numbers of biological entities, and the amorphous, gas, and liquid phases. These entities sequester elements and mix incompletely; therefore, the surface earth demonstrates extreme levels of heterogeneity that changes over space and time. It is precisely this complexity and heterogeneity that geochemists love to study.

The GS can move geochemistry forward scientifically and sociologically by promoting the synthesis of these geochemical datasets with an eye toward finding the important patterns that allow prediction. Specifically, the GS should catalyze the publication of geochemical data on the web.

Does this seem banal and uninteresting? It did to me at first. But now I see it as perhaps the best step toward unifying our disparate thoughts into a coherent voice. The difficult process of organizing all of our data into a useful resource on the web will require collaboration among the professional societies, the funding agencies, and the publishing houses.

Once multiple large datasets are accessible to all, we will have more geochemical minds considering the patterns that are manifest across scales of space and time. Importantly, we will not be able to understand those patterns, so we will rush to create the models explaining the patterns. As models explain the online data, we will notice that some data are missing. That will force us to develop better networks of earth and environmental observing systems. The synthesis of data will highlight inconsistencies in measurements and will force us to grit our teeth and agree how to make standard measurements. We will argue about how long a publicly financed scientist can keep public data private. All of these processes could be – and should be -- promoted by the GS.

To state my thesis succinctly using a paraphrase of a famous line from a recent U.S. Presidential election, “It’s all about the data, stupid!”

Susan L. Brantley, President of the Geochemical Society
Earth and Environmental Sciences Institute
Pennsylvania State University
University Park, PA 16802