Volcanoes, geochemistry and me – a Coursera challenge

The reason I’m not a geologist today is because, no matter how hard I tried, I could not understand geochemistry when going for an undergraduate degree back in the 1980s.

That was terribly frustrating and depressing, but instead I found a worthwhile alternative: developing the skill set required to transcribe dictation, learning a medical dictionary’s worth of vocabulary, and practicing until I can type it out accurately at 100 wpm plus – that is, medical transcription.

Nobody outside the field really understands how much is involved with it. Computerized transcription will never replace it until computers have first totally replaced physicians, and that’s not ever going to happen.

The view

Anyway, when the Internet became popular, I very slowly but inevitably got interested in geology again. It was a very messy process because it meant revisiting all that pain and frustration again. However, I got through that and discovered just how right it had been that I had dropped out before.

You see, I had been all about the view and still was. I misunderstood the scientific process – you don’t totally rely on others, as I had been expecting to rely on geochemistry experts while pursuing my favorite subdivision of geology, that of geophysics.

Now I understand things better. You have to bring a good store of all-around basic knowledge to the field before you can interact with it in any meaningful way or go on to develop a specialty in something you’re very interested in.

I would have made a terrible geologist, had I continued back in the 1980s and gotten that degree. So, all around, everybody benefited by that early failure.

The challenge today

I feel ready for a classroom again and recently signed up for a Coursera online geology course, “Volcanic Eruptions: a material science.” The syllabus was brief but sounded interesting.

However, the course begins soon and they’ve updated the syllabus with detail that gave me pause when I looked it over this morning:

Course Syllabus
Week 1: The Earth as a living planet: The five big extinctions during Phanerozoic times; Volcanic fatalities; Volcanism in the Solar System; Volcanism on Earth; the essence of volcanism

Week 2: The Earth as a living planet: Volcanoes on Earth: magnitudes and landforms; explosive and effusive volcanism; videos on Merapi and Etna volcanoes; volcanic marerials; mineralogy and fragments classification; chemical and mineralogical classification

Week 3: Structure of Molten Silicates: Chemical composition; stability and geological properties (an overview on viscosity/viscoelasticity; density, expansivity / compressibility; volatiles solubilities, diffusivities, heat capacity, redox equilibria); structure of Molten Silicates

Week 4: Dynamics of Molten Silicates; glass and molten silicates; molar heat, enthalpy: strain vs. time; cooling vs. heating pathes; Maxwell relations for viscoelasticity; resistivity and viscosity; relaxation times and implications for experiments

Week 5: Relaxation in Silicate melts; longitudinal vsshear viscosity; glass transition; quench rate, relaxation time and viscosity; the role of water content, water speciation, pressure and temperature; details of water speciation from experimental data

Week 6: Diffusion in Silicate Melts; water content and water speciation (cont.); diffusion in contrasting silicate melts; the role of temperature; comparing diffusion of different elements; the role of pressure; simplified Stokes-Einstein and Eyring equations; relaxation times (comparison between different compositions at different temperatures)

Week 7: Density/equation of state for liquid silicates

Week 8: Viscosity of silicate melts

Week 9: Fragmentation of magmas. The process chain: What is a volcano doing?

Week 10: Impact and relevance, Volcanoes and Mankind; Hazards mitigation

Recommended Background
Basic physics and chemistry.

At first I was all

David Fisher

Source: David Fisher

But now I’m more

Source:  Tanjila

Source: Tanjila

After all, I’m familiar with most of those words in the syllabus.

I did pass mineralogy, with tutoring from a very patient grad student.

I certainly do have at least a basic chemistry background (I worked very hard at that before giving up).

Most importantly, I want to know more about volcanoes. In the Eighties, I more or less just fell into geology. Now I’m actively seeking it out. Maybe this time it will be different.

Well, we’ll see how it goes. The course is free, so I won’t be out anything if it turns out that geochemistry is still impenetrable for me. On the other hand, if it clicks this time around, what a world of wonders that will open up!

Categories: volcanoes

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