PhD profile #3 – KT

KT CooperKT Cooper – 3rd year PhD student
“The development of porosity and permeability in modern carbonate environments: a combined modelling and field work study”

1) The Twitter challenge: Your PhD in 140 characters

Measuring and modelling dissolution of modern carbonates (limestone) by monitoring the groundwater biogeochemistry in the Bahamas.

2) How are you pushing the frontiers of science?

My PhD has changed course over the past year and it seems like I might be pushing a different frontier in science than was first planned!

KT in the rain
Collecting rainwater during a large storm event on North Andros in the Bahamas. This is not my normal fieldwork attire but I never like to miss an opportunity to collect samples!

Initially, I set out to understand how modern carbonates are altered when meteoric (fresh) water interacts with them.  Does this water dissolve the limestone or does it precipitate cements?  The driving force for understanding present environments is that they are a window into the past.  This is where modelling steps in.  If you can model the modern processes you observe over geological time (thousands and thousands of years) then this can tell you information on the distribution of these alterations, which are collectively termed diagenesisThe pattern of alteration is of great interest to oil and gas companies because carbonate rocks host a large amount of oil; however, it is notoriously difficult to work out where that oil might because carbonates tend to be quite holey in some locations and fairly tight (lots of cement) in others.

Through observing the modern environment, my PhD drifted into looking at the meteoric system in a more holistic manner.  I not only look at the geochemistry of the water (which is an indicator of the water-rock interactions which drive the diagenesis) but also what the microbial communities are up to and how this might enhance the diagenesis.  Essentially, I am now trying to combine both the geochemistry and “hard rock” science with the microbiology.

3) What part of your work do you enjoy the most?

It sounds a little clichéd but I think that learning new things is the most enjoyable part of the process.

4) What’s the most challenging aspect?

My PhD has a number of aspects to it which all carry their own challenge. I have been involved in extensive fieldwork seasons in the Bahamas, as well as analysing my own waters and performing some computer-based modelling of geochemistry and, eventually, biogeochemistry.  The issues with some of these aspects are too numerous and tedious to mention, but I would say the most challenging part of the work is when things aren’t working and this is out of your control.  There is nothing more frustrating than when a machine stops working and delays your well made plans!

5) Favourite piece of equipment

My lovely multimeter with all its probes neatly packed away in its field case.  It never looked so good.
My lovely multi-meter with all its probes neatly packed away in its field case. It never looked so good.

My favourite piece of equipment is my multi-meter, which I truly love.  A multi-meter is a piece of field equipment which allows you to measure the pH (acidity), temperature, electrical conductivity (proxy for salinity) and the amount of dissolved oxygen in water.  As mine is a brand new model, it has many bells and whistles, which I fully exploited while I was on fieldwork.  We left it overnight in a lake to log every 15 minutes.  The data indicated that the when the sun went down the water chemistry changed; this was due to the fact that the microbes living in the water were no longer photosynthesising.  If I didn’t have my meter I wouldn’t have known that.

6) Best travel perk of the job

Fieldwork is good to an extent (I shouldn’t complain about this but it’s not all sitting on the beach working on our tans) but I would have to say post-conference trips are the best travel perk.  Over the past few years I have been to a number of international meetings and often you don’t get the opportunity to enjoy the area you are staying in.  But occasionally you get the chance to hang around after the conference and enjoy the amazing location.  One trip which stands out for me was an organised field trip after a karst (which is the collective term for holes, fist sized to caves, in limestone rocks) conference in Montana.  We went to see the Big Horn Basin, a sedimentary basin where oil was formed and has been produced.  It sounds pretty boring to most people but when you’re on a boat trip for 5 hours and literally all you see are folded colourful rocks, it’s pretty breath-taking.  As a non-geologist (I’m an environmental geoscientist by training), I do enjoy colour coded geology!

The Big Horn Basin, Montana, with wonderful colour coded strata and just breath-taking scenery.
The Big Horn Basin, Montana, with wonderful colour coded strata and just breath-taking scenery.

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About KT Cooper

I’m a carbonate biogeochemist. When I’m not in the Bahamas, I dabble in the world of computer modelling.

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