ENSO (is taking over my life)

It’s been awhile since I’ve posted some hard-core science (and I’m totally a day late on my Wednesday post-day), so I felt this week was as good as any to let you all in on my not-so-well-kept secret of a PhD project that has been taking over my life. The topic: paleo-ENSO.

To start, let me define what the heck that means. Paleo = ancient. ENSO = El Nino Southern Oscillation…so I will be studying ancient El Niño Southern Oscillation. Still have no idea what ENSO is? Well for one, you should. And two, ENSO is the leading mode of climate variability on Earth today. In non-ENSO-studying-PhD-student terms, ENSO is incredibly important for short term changes in climate and has a massive impact on weather, precipitation and drought patterns around the world, including the current drought and resultant fires slamming Indonesia (click here for good review on the variable impacts of El Niño around the world — I promise it’s not a trap). ENSO is initiated in equatorial Pacific (you know, the region in the Pacific ocean that’s closest to the equator), but that doesn’t stop it from dipping it’s selfish hands in everyone else’s business.


Diverging from the paleo for a bit, let me explain a bit more about ENSO.

ENSO includes two very prominent phases, which I’m sure you are at least somewhat familiar with in the deepest parts of your brain: El Niño (“warm” episode) and La Niña (“cold” episode).

El Niño

El Niño is the “warm” phase of ENSO. I put warm in quotations because the warm refers to sea surface temperature anomalies (the difference between observed sea surface temperature and average or normal sea surface temperature) in a very specific location in the eastern equatorial Pacific, which is referred to by all us fancy scientists as the Cold Tongue (named because under normal conditions, this area is cool). Simply put, during an El Niño event (like the one that we are in right now), the water in the Cold Tongue warms up.

Now, this sea surface temperature warming doesn’t just sit there all by itself doing nothing–the atmosphere wants to play too (sometimes). And when the atmosphere decides to play ball, that’s when things get interesting. Anomalous warming in the eastern equatorial Pacific (often, but not always) triggers a response in the atmosphere, which results a shift in atmospheric circulation. This shift in atmospheric circulation brings rain to the southwestern US and northwestern South America, and drought to Indonesia, parts of northeastern Australia and even South Africa.

La Niña

La Niña is the “cold” phase of ENSO. Again, I put the cold in quotations because the cold refers to sea surface temperature anomalies in the Cold Tongue of the eastern equatorial Pacific. During a La Niña event, the water in the Cold Tongue gets colder (yes… it does that). The atmosphere feels these cooler temperatures (just as it feels the warmer sea surface temperatures during an El Niño) and “cool” stuff happens. An opposite shift in atmospheric circulation brings rain to Indonesia, northeastern Australia and South Africa and drought to the southwestern US and northwestern South America.

Some final notes on ENSO before I move back to the paleo side of things:

(1) Not all El Niño or La Niña events are the same–there is a lot of variability in how these events present themselves both in the ocean and the atmosphere and in what impacts are felt around the globe.

(2) If the atmosphere doesn’t want to play ball, a full blown El Niño or La Niña event is highly unlikely. (Case and point, last year’s failed El Niño).

(3) El Niño events tend to me much stronger in amplitude than La Niña events, and therefore tend to gather more interest in the popular media. (There are also scientists who believe that La Niña events are simply just a slight amplification of normal conditions, and therefore not a “real” event… but that’s a discussion for another time).

Okay, now back to the paleo.

Why study paleo-ENSO?

(1) Paleo for paleo’s sake.

It’s interesting! The Earth is cool, guys, and studying everything about it is super exciting (#geologyrocks). But sad-face, I had to pick one topic to focus on for the next few years and ENSO just won me over.

To get more serious: The way in which ENSO presents itself today in the modern is likely not how ENSO presented itself in the past. Studying ENSO in the past can help us better understand the phenomenon itself. (But really, it’s just super cool).

(2) Paleo for the future’s sake.

Scientists have no idea how climate change will effect ENSO. Models disagree about how variable (i.e. how often El Niño and La Niña events occur) ENSO will be in the future. One way to resolve this issue is to test models against data collected from ancient time periods to observe how well these models simulate paleo-ENSO (i.e. run these models for a time period we understand well in the past and compare the model outputs to non-model data from the same time period). Any divergences between these models and robust (i.e. accurate, precise and thoroughly vetted) ancient data would suggest a huge misunderstanding of the basic physics of ENSO in the models. However, in order to do this you need really, really good data. And for anything older than ~10,000 years, we don’t have that. And this is where I (super-paleo-ENSO-PhD-student) come in.

To condense that whole paragraph down into one sentence: Understanding ENSO in the past is vital for understanding how ENSO will change in the future.

Okay cool, but how do you study paleo-ENSO?


Specifically carbonate geochemistry (see my about me bonus for a lengthy discussion). I’m not going to get into all the dirty details, but simply put, scientists can extract a glorious amount of climate information from carbonates. One of these things is sea surface temperature. And when sea surface temperature data is collected from ENSO affected regions in the equatorial Pacific Ocean (particularly those regions which are being used to monitor ENSO today)–BAM, you have a way to reconstruct ENSO. Now of course there a lot of complicated things that go into this sort of analysis, such as the need for high resolution records (i.e. a record that preserves the short-term variability of ENSO) and incorporating other proxy data results from around the world, but it can AND has been done. (And I’m going to do it–for a period of Earth’s history for which we have absolutely no idea what in the world ENSO was doing).


I’ve spent most of this semester learning all things ENSO. I’ve written a National Science Foundation Graduate Research Fellowship Program proposal on it. I’m collecting all the papers I can find about it. I’ve been talking to members of my PhD committee about it.

And the best part… I get to do this for five years.








Why the Earth’s past has scientists so worried about the Atlantic Ocean’s circulation – The Washington Post

Because here’s an article that says all the things I want to say on this topic and because I didn’t have time to write something myself this week… Marine geology is important guys!

***Ocean circulation changed many times in the last 70,000 years, according to new research.

Source: Why the Earth’s past has scientists so worried about the Atlantic Ocean’s circulation – The Washington Post

Scientific literacy: Lessons from The Martian

As I was walking out of the theatre after seeing The Martian last Friday, I noticed a tweet by one of my favorite scientists, Neil deGrasse Tyson, which summed up the movie (and by relation, the novel) so well that I couldn’t believe I hadn’t though of it before: “The @MartianMovie — where you learn all the ways that being Scientifically Literate can save your life.” Besides the fact that I love almost everything Neil deGrasse Tyson says (it’s all relevant, I swear), this tweet hits on something that goes much deeper than a quirky blip about a popular new movie. Scientific literacy.
Screen Shot 2015-10-02 at 5.54.23 PM

What is scientific literacy?

The long definition: “Scientific literacy means that a person can ask, find, or determine answers to questions derived from curiosity about everyday experiences. It means that a person has the ability to describe, explain, and predict natural phenomena. Scientific literacy entails being able to read with understanding articles about science in the popular press and to engage in social conversation about the validity of the conclusions. Scientific literacy implies that a person can identify scientific issues underlying national and local decisions and express positions that are scientifically and technologically informed. A literate citizen should be able to evaluate the quality of scientific information on the basis of its source and the methods used to generate it. Scientific literacy also implies the capacity to pose and evaluate arguments based on evidence and to apply conclusions from such arguments appropriately.” (National Science Education Standards, page 22)

The short definition, scientific literacy is the “knowledge and understanding of scientific concepts and processes required for personal decision making, participation in civic and cultural affairs, and economic productivity.” (National Science Education Standards)

To summarize, scientific literacy implies that one has been thoroughly educated in the scientific process and can apply the things they have learned to real life situations.

Scientific literacy is the "knowledge and understanding of scientific 
concepts and processes required for personal decision making, participation 
in civic and cultural affairs, and economic productivity." 
(National Science Education Standards)

Why is The Martian so important?

If you haven’t read the book or seen the movie (but seriously read it too)—READ/WATCH IT! As a scientist, I can’t think of a better example of scientific triumph in the world of fiction. The author, Andy Weir, is a software engineer, who set out to write a novel grounded in scientific truth. He did amazingly well–I’m only aware of one scientific mishap/exaggeration regarding how Martian weather is depicted (and forces the Hermes crew to evacuate and thus leave Mark Watney behind). However, the rest of the novel is filled with the scientific success (and blunders) of Mark Watney as he tries to wrestle his survival from Mars.

After Mark Watney is mistakenly left on Mars by his team, he has no choice but to “science the shit out of this.” As the mission’s botanist and mechanical engineer, his abilities are admittedly perfectly suited to his stranded on Mars situation (i.e. he must figure out how to make his food last until he can be rescued and he must rig equipment for new uses); however, much of the work he does need to complete to survive is beyond his normal comfort zone, and he must rely on his ability to use science to solve problems. For those of you who have read the book or seen the movie, you know how this ends–I won’t give it away for those who have not, but the message is the same–Mark Watney’s life depends TOTALLY on his scientific knowledge and ability to adapt using the tools he has around him.

Now, not everyone on this planet is astronaut material. Mark Wartney and the rest of the Hermes crew were the best of the best (just like all those super-human real life astronauts) and they were likely picked for the mission because of their specific skills. However, this doesn’t mean that the rest of us stuck back down on Earth should be able to avoid our worldly responsibilities because “science isn’t our thing.”

Okay… but we’re never going to be stuck on Mars right?

Chances are no. But our planet is currently facing its own “struggle for survival’, which is only being hindered by the general public’s lack of scientific literacy.

Struggle for survival, you say? On Earth?

You might be tempted to think that scientific literacy has absolutely nothing to do with human survival on Earth, but I strongly disagree. Our planet is currently faced with with a rate of warming likely unmatched in its geologic history. Anthropogenic CO2 is being rapidly released into the atmosphere through burning of fossil fuels and disturbance of other carbon sinks, such as the world’s forests and permafrost in arctic and alpine regions. Glaciers are melting and sending a large amount of fresh water into the oceans causing changes in ocean circulation. Species are being lost at an incredible rate. The only way to lessen or reverse these effects, is for people to understand and accept these changes and to move into action to do something about it. Without action, humans (and everything else living on this planet) face an extremely uncertain future in a rapidly changing world–evolution takes millions of years, and humans may not be able to adapt to these changes quickly enough. Like Mark Watney, humans must “science the shit out of this” for survival.

So why aren’t more people jumping into action?

There is a terrifying lack of scientific literacy in the United States and other countries around the world. People misunderstand the scientific process, and therefore misunderstand the consensus among climate scientists in term of anthropogenic climate change (for the record, 97% of scientists AGREE that anthropogenic climate change is real—see Skeptical Science – Getting skeptical about global warming skepticism). These misunderstandings lead to a feeling that science is bad or inaccurate. They lead to the thoughts that scientists are radicals who just want attention. They even lead to complete ignorance about how important the scientific process is (i.e. what it means to have something published in a peer reviewed journal vs. just somewhere online). And when politicians and people of power use their lack of scientific literacy to spread false information about climate change, nothing gets done.

We all need to do better. Not all of us are scientists (and most of us will never set foot on Mars let alone get anywhere near space), and that’s fine. But America (and the rest of the world) needs to work harder to improve the scientific literacy of its citizens. Without a general understanding of science, people will continue to doubt everything about it. If people continue to doubt science, they will never trust it to save their lives. If people don’t trust science to save their lives… well, that doesn’t leave a very shiny, bright future for planet Earth.

If cats were geologists

Cats are magnificent beasts. And so are geologists. And because my brain is too fried to write anything else (thanks Matlab and fellowship applications and grading and life), I present a photo montage entitled: If cats were geologists.

The oh my god I just did something horribly, horribly wrong and my data is so, so wrong geologist


The please give me money for science geologist


The eat all the things in sight (including the mystery meat) after a long day in the field geologist


The trying to take a group photo geologist


The just lost your mapping partner and start hearing scary noises in the woods geologistsurprised cat

The freshman geologist cat


The grad student geologist


The after being stuck in the rain all day mapping geologist


The I’m so tired I think I could die after weeks of fieldwork or proposal/grant/thesis writing geologist


The I’m just going to sleep here (after a night of magical liquid consumption) geologistdrunkcat

The you can’t make me go back to the lab geologist


The I’m very skeptical about this data geologist


The how out of shape you feel after months away from the field geologist


The just tried to take a picture of a rock but the selfie cam was on geologist


The this is my rock, this is totally my rock geologist


Things you should know before befriending a geologist

Us geologists are a special breed. We definitely aren’t like everyone else. So, if you’re thinking about befriending a geologist, there’s probably a few things you should know:

You can’t take us anywhere. Well, you can, but you’ve been forewarned… Geologists are distracted by everything. And when I say everything, I mean rocks. Rocks are everywhere. And we’re very good at finding them. And spending forever looking at them. And talking about them. And boring you with all the details about them. And debating with ourselves and each other about them. So like I said, you can’t take us anywhere.

We collect all the rocks. Okay, so not all the rocks… but definitely MOST of the rocks. When we hike, our packs are heavier coming down than they were going up. When we move, we have boxes of just rocks–so beware of agreeing to help a geologist move… we’ll probably make you carry all the heavy stuff. Every space we can claim as our own is filled with our rocks. Our kitchens, our living rooms, our bedrooms, our offices, and yes likely even our bathrooms play home to at least one of our magnificent rock finds.


Mike (still) rock hunting on the final day of our trek in Nepal

We will make you hike with us. And it won’t be just any kind of hike, it’ll be a geologist hike, which means we’ll make you stop every five seconds to look at rocks or we’ll race you to death up the mountain. We also have perfected the art of hiking in torrential downpour, or damning heat, or snowstorms, or up (and down) scree… and it won’t stop us from babbling away about the rocks or yes, even taking notes on our glorious homemade map boards. And if you dare ask us a question about geology, you’ll have opened a whole rabbit hole of topics that you probably will wish you hadn’t.

We make lame geology jokes. And like them. And think you like them too. Are you cummingtonite? That’s a gneiss schist. Rocks rock… you get the picture. We may roll our eyes when someone resorts the geology pun game, but deep down it makes all warm and fuzzy inside.

We like adult beverages. A lot. It hasn’t been a successful day in the field without some sort of liquid wonder. Beer is a major staple of our diet. We don’t go anywhere without a beer plan. And when we go to Utah, we make sure to stop in Colorado… or Wyoming to get the good beer before we go back to 3.2 land. And yes, some of us are fancier than others, so wine is the adult beverage of choice. However, don’t ever ask a group of geologist to agree on the best kind of liquor because consensus you won’t find (my vote is still gin guys).


We love to talk geology. Seriously. If you ask us a question, we won’t stop talking about it. And we LOVE when people ask us questions… because it lets us show all you “normal” people just how wonderfully smart and insightful we are. But when you bring us concrete and ask us to identify the rock, you should probably cross your fingers that our rock hammer isn’t within reach.

We love to hate bad geology movies. The Core. Dante’s Peak. Journey to the Center of the Earth. San Andreas. We love to hate them all. And we’ll probably make you watch them. And make you listen to us grumble about how horribly inaccurate they are. And we’ll definitely try to teach you everything the right way (whether you asked for it or not).

Field season is our happiest time of the year. Camping, getting dirty, rock hunting, mapping, researching, [working hard and playing hard]… we love all these things. Field season is the time of the year when we get to do all these glorious things. But sorry, we can’t invite you. It’s an exclusive club kind of thing. And for those of us whose fieldwork is a one-time deal or whose fieldwork has already been completed, we just hope and pray that one of our rock loving friends will let us tag along on their own field adventures.

We ALWAYS remember that one time at field camp. You know that time? We have absolutely no shame constantly reminding all you normal folk just how awesome our field camp/field trip/field season experience was. And when our field groups reunite, SO MANY INSIDE JOKES.

And last but not least… We will try to convert you. 

Lab life: the cleanroom, the machine, the clothes, the work, and the fun

Last week was all about me, but this week is all about the lab. As I dove into in my About me bonus, I am a paleoceanographer, paleoclimatologist and a geochemist. Specifically, I use certain elements, mainly Mg/Ca ratios, to reconstruct past oceans and climate. To do that, I need a lab. But not just any a lab; I need a lab with a (very) cleanroom, a very nifty inductively coupled plasma mass spectrometer (ICP-MS), some wonderfully fashionable and functional clothing, and of course, a lot of interesting and exciting work. Here at INSTAAR, we call that lab the ICP-MS Trace Element Lab. And it’s in this lab where all my PhD dreams will come true (or explode catastrophically).

The cleanroom

What’s a cleanroom? Well, a cleanroom, is a room that limits the introduction of contaminants (i.e. dust, airborne particles, pollutants, etc.) through engineering controls to preserve process or sample integrity. Why do I need a cleanroom? The samples I work with are very specific to a source (where the sample came from) and a time (when the sample was “made”). This means that all the elements stored within a sample will be different from a sample taken somewhere else. The elements will also be different from the environment, let’s say, in a geology building. If a processing or dissolved sample (i.e. a sample that is being prepped for analysis on a machine) sits out in the un-protected geology building environment, it can uncontrollably “take in” or react with the set of elements its composition differs from because of its vulnerable state. This isn’t good. A contaminated sample will no longer accurately represent its source and time, thereby possibly changing the history the geochemist (i.e. me) will try to discern from said sample. This is where the cleanroom comes in; it limits sample contamination by controlling the environment.


A cleanroom to a geochemist is like a operating room to a surgeon; IT’S VERY IMPORTANT. It’s where we work our science magic (or sometimes where our dreams are crushed). Without getting too technical, my samples need to remain as clean (i.e. not contaminated) as possible through crushing, cleaning and dissolving steps (i.e. prepping for analysis) in order to accurately represent its history. Engineering controls, such as air filters, negative room pressure, laminar flow benches, and even coated metals (or better yet, metal substitutes) are used to limit sample contamination. Because we’re scientists, we have all sorts of checks to determine if contamination did indeed occur, such as: running a acid blank (no sample) test prior to using said acid to dissolve a sample or analyzing acid blanks during a sample run to determine if contamination occurred while dissolving samples. However, even in a cleanroom, contamination does still occur.

The machine

What’s an ICP-MS? It’s a mass spectrometer with energized plasma that ionizes a dissolved (liquid) sample to analyze a set of specific elements. Decoded: an ICP-MS will take a dissolved sample, analyze it and report a specific suite of elements. The suite of elements the ICP-MS reports depends on a couple things, mainly: the analytical precision and sensitivity needed to complete a run (some samples are smaller than others and thus require more precision and sensitivity to be successfully analyzed) and the interests of the researcher using the machine. I could go into all the physics behind this glorious machine, but as I myself am still learning them… I won’t. Just know this: Mg/Ca are the elements I’m mainly after and I will use this machine to find them. I will also analyze my samples for other elements, but that is a discussion for another day.

The ICP-MS is housed in an adjoining room to the cleanroom, and like the cleanroom, is a vital part of the lab I will be working in throughout my entire PhD career.

The clothes

IMG_5010I’ve been talking a lot about the air contamination, but contamination doesn’t just come from the air; it can also come from particles trapped in clothing. Because outside clothes and shoes, are well, from the outside, they must be covered at all times when in a cleanroom. In most geochemical labs, the coverings include a stunning white tyvek suit and booties. This makes us cleanroom geochemists the most stylist of the geology bunch.

Fashion joking aside, personal protective equipment (PPE) is a huge and vital part of any lab. The main function of the tyvek suit and booties is to protect the cleanroom from outside contaminants, but a secondary function is that it can protect one’s body from minor chemical spills. Gloves and googles/glasses top off the glorious cleanroom ensemble to protect our dainty hands and seeing organs–safety first. My PPE is designed to handle less hazardous material as the chemicals I work with are very dilute; however, I do still handle chemical stock solutions and other concentrated chemicals, so I still have to be very careful in the lab.

The work

Of course, working in any lab requires a significant amount of training (and often a very large learning curve). From safety training, to process training, to day-to-day maintenance, to just finding the damn pipette tips… a new labbie could spend anywhere from a few weeks to an entire year getting comfortable in a new lab. When a lab contains a cleanroom, one must follow an even higher level of scrutiny. Lucky for me, I worked in a similar cleanroom setting as an undergrad, so some of the basic concepts (i.e. upkeep, storage, cleaning, safety) are review for me. Unlucky for me, lots of other parts of my new clean lab (i.e. anything and everything foram and ICP-MS) are completely new to me, and it will still take some time (and lots of mistakes) for me to get 100% comfortable.

Lab Hazard Rating System

Via “Piled Higher and Deeper” by Jorge Cham, http://www.phdcomics.com

My PhD will likely be lab heavy in the first couple of years. Some days, I won’t leave the lab (probably not by choice, but hey, when in PhD mode, one must PhD). Others, I’ll run far, far away from it (hopefully to be super productive reading and writing, but more likely I’ll be looking for beer). During my PhD, my lab work will include all sorts of tasks: foram picking, crushing, cleaning, dissolving and analyzing; chemical dilutions; lab cleaning and organizing; beaker/cup cleaning; ICP-MSing (i.e. sweet talking the inductively coupled plasma mass spectrometer); and many, many more. The foram tasks will take by far the longest, and most of those tasks require use of the cleanroom. Use of the ICP-MS will also be somewhat time consuming, especially when the machine is being difficult (as I write this, my advisor and I are trying to keep it from overheating so we can finally run some samples). However, I’ve spent my summer learning a lot about the machine, and hopefully by the time my own samples are ready to be run, I’ll be a super knowledgable (or at least semi-knowledgeable) ICP-MSer.

The fun

But life in the lab goes beyond the lab, the clothes and even the work; you learn along the way to have a little fun and to make a little fun of your mistakes or tragically embarrassing situations. To let you in on the “fun” part, I’ve decided to write about some of the funny situations you could find yourself in while working in a cleanroom. So, without further ado, I present:

You know you work (or have worked) in a cleanroom when…

  • You can replicate the delicate dance of putting on and (the often more difficult task) of taking off your tyvek (“bunny”) suit and shoe coverings in your sleep
  • You’ve fallen over trying to get your limbs out of your tyvek suit (probably in front of your advisor or professor or a very important world-renown scientist)
  • You’ve made the mistake of completely suiting up after drinking five cups of coffee… and not running to the bathroom first
  • You’ve found the “slippery” part of the cleanroom floor and know first hand what it’s like to feel as if your life is about to end (since you’re holding very delicate samples, and/or scary acids, and/or your advisor is standing right behind you)
  • You don’t care what you wear to work because nothing’s more fashionable than tyvek white
  • You’ve tried to sit down on a normal office chair while donning your tyvek suit and have gone flying off the chair Christmas Vacation sledding style
  • You’ve made the mistake of leaving your notes on the wrong side of the cleanroom and not realizing it until after removing all your fancy cleanroom clothes
  • You’ve made the mistake of leaving your notes in another room and not realizing it until after completely suiting up
  • You know what it feels like for people to think you’re about to get into some serious shit… but you’re really just going in the lab to clean some beakers
  • You look like a giant marsh-mellow… and like it
  • You know the struggle of trying to get your cell phone out of your back pocket once you’re already suited and zipped up
  • Your favorite time of the week/month is when you get to rip off the nasty sticky pads at all door entrances to reveal the brand new sticky pads underneath
  • You know what it’s like for something to come up in the lab where you need help from your more experienced advisor, lab manager or the lab’s grad-student/postdoc extraordinaire and have the internal debate about whether you should completely un-suit to hunt him/her down… or shamelessly text him/her until he/she comes to your rescue
  • You get angry over someone using the tyvek suit CLEARLY labeled with your name


About me bonus: what I do, why I do it and the basic science behind my PhD

By now, most of you are well aware of my love affair with geology. However, some of you may still not exactly understand what I do or why I do it or have any idea what my upcoming PhD focus means. Because my work will never be an easy explanation for those unfamiliar with what I do, I decided to take this week to describe as best I could (and as un-jargony as possible) what I do, why I do it and the basic science behind my PhD. Eventually, I’ll add or link a shortened version of this to my about me (hence the title), but I felt these words were probably best served first as a standalone post.

As with many geologists, I study the past. I do this for a variety of reasons. First and foremost, I enjoy it. It’s exciting for me to dig into Earth’s history and learn something we didn’t know before or better understand something than we did before. Second, Earth is extremely complex. Studying modern-day change is vital to understanding the complex relationships of Earth systems, but studying the past, and all its glorious “natural experiments,” allows scientists to explore Earth dynamics beyond modern constraints. The past was different than today, and understanding the differences between ancient and modern Earth is extremely important. Lastly, studying the past allows scientist to apply past analogs to future scenarios (i.e. using the past to inform the future) not only in an effort to predict possible outcomes, but also to help the world prepare to face those outcomes. The latter point is the most important to me. We live in a rapidly changing world where human actions have a resounding impact on Earth’s future. Understanding how our planet responded and reacted to past changes, is our greatest hope to predict, plan and prepare for (and in an ideal world, limit) the negative impacts stemming from modern human actions on the complex Earth system.

climate comic

Extremely relevant Joel Pett cartoon, USA Today (2009)

There are lots of ways to study the past, which is why there are lots of different types of geologists (and paleo-[add your science here]-ists). There are geologists who study large, massive structures in ancient formations that are visible for miles away, and there are geologists who study the chemical make-up of rocks and minerals that can only be be discerned after hours of laboratory prep and machine analysis. Some geologists focus on deep time, while others focus on more recent events. Then there are geologists who wander all around the geologic boundaries, putting on all sorts of geologic hats in an attempt to better understand our wonderfully complex planet. Pick any topic and any time period (or even multiple combinations as insane as it may seem), and I guarantee you there’s a geologist somewhere dedicating his or her life to that very geologic niche.

In the spectrum of geologic possibilities, I am a paleoceanographer, paleoclimatologist and geochemist focused (for now) mainly on the more recent geologic past. To decode that geological jargon: I study ancient (but not too ancient) oceans and climate, and I use elements (i.e. chemistry) to discern past events (i.e. geology). Simply put, I’m one of those that wears lots of hats. And to make it even more confusing for you, all of the aforementioned words I used to describe myself as a geologist don’t necessarily make me a geologist at all. Paleoceanographers and paleoclimatologists come from all walks of scientific life. Some are geologists, yes, but many are atmospheric and oceanic scientists, or physicists, or chemists, or even biologists and statisticians. And like the word spells out for you, geochemists are often trained chemists “dabbling” in the world of geology. I will spend the next five years dipping my toes into geology… and all the other wonderful sciences that play a role at the cross-section of paleoceanography, paleoclimatology and geochemistry. Needless to say, I will be very busy as PhD student (gathering lots of pretty hats).

g. ruber foram

An example of fossil foraminifera. See source for detail: Thirumalai et al. (2014), Globigerinoides ruber morphotypes in the Gulf of Mexico: A test of null hypothesis. Scientific Reports 4, 6018. doi: 10.1038/srep06018

Now for the technical stuff. For my science readers–this will probably be easy for you to follow. For all my other readers–I’ll do my best to de-jargon. During my PhD, I will be using (i.e. picking, processing, dissolving and analyzing) fossil foraminifera (a marine protist with a calcite shell–here’s Wikipedia) that have been preserved in ocean sediments to determine and understand past ocean and climate states, changes and relationships. How will I do that?: magnesium (Mg) and calcium (Ca). Mg/Ca ratios can be used as a paleo-proxy (i.e. recorder of the past) for temperature. Simply (and without sending this post down the rabbit-hole of Mg/Ca relationships), the amount of Mg in a calcite mineral relates to the temperature at which that mineral was formed; the more Mg that is in a calcite, the higher the temperature was at the time of formation. In the case of formanifera, or forams, the temperature recorded by a calcite shell is the temperature of the sea water surrounding the foram at the time of shell formation or its calcification temperature. Pretty cool, right? (Yeah, I think so). Measuring Mg/Ca ratios in fossil forams allows scientists to calculate past ocean temperatures! (I know you’re as excited as I am). The exact Mg/Ca-temperature relationship can be dependent on other factors, including foram species, habitat, salinity and even dissolution effects (all things I won’t get into here as it would turn this post into a lengthy research project), but some very, very smart people have developed a myriad of calibration equations (i.e. equations that directly relate Mg/Ca ratios to temperature) to isolate the temperature signal.

Phew. If you made it this far–HIGH FIVE!

Now, some of you are probably wondering exactly how ancient ocean temperatures are going to help me determine and understand past ocean AND climate states, changes and relationships–and that would be a very fair thing for you to wonder. The ocean plays a major role in the Earth climate system, which also includes very important things such as the biosphere and the atmosphere. A perturbation in one part of the system often affects the other parts of the system. For example, a major shift in surface temperatures on Earth will cause a shift in ocean temperatures, which will cause a change in atmospheric winds and weather, which will affect the plants and animals dependent on all those things (…so on and so forth). Understanding the whole Earth climate system requires knowledge of all its parts. And knowledge of one part can also lead to insights on others. I choose to study the ocean because it’s a part of the Earth climate system that we probably know and understand the least about. And while the ocean is only one piece of the giant, complicated climate puzzle, its piece and its close connection with other pieces can tell us a lot about the past. So really, my ancient ocean temperatures will actually tell me a lot more than a simple reading on a thermometer. For those curious about exactly what my PhD project will be, I’ll probably reveal more about that later down the road. As a new graduate student, I’m focused mainly on catching up on the slew of wonderful Mg/Ca-foram literature (I still have a lot to learn), and while I have a pretty good idea where my project is going, things can always change.