Time Scavengers

I am a paleoceanographer. Basically, I study how the ocean changed in the past, in order to understand how it might change in the future. To do this, I primarily use foraminifera, which are sand-sized plankton that have a hard shell that is easily preserved in ancient sediments. In fact, in many places far from land the sea floor is entirely made of foraminifera and other microfossils (fossils so tiny, you need a microscope to see them properly or at all). To get the microfossils, I often go in the field or to sea. I do a lot of work with core samples of both ancient and modern sediments from the deep sea and on the continental shelf, and also collect samples from outcrop on land where the sea used to be.

My research touches on a number of societally relevant topics, although if I’m honest my main motivation is just to better understand how the world works. I like when my work addresses specific problems like declining oxygen in the oceans, but there is value in all kinds of science, and you never know what discoveries might lead to an important insight into processes that are significant today. That being said, much of my work focuses on how anoxia (i.e., no dissolved oxygen in the water) develops in the ocean, and how marine life responded to it in the past.

A combination of warming water due to climate change and plankton blooms due to increased nutrient runoff from agriculture on land has led to a recent decline in the amount of oxygen in the oceans. In turn, this had led to an expansion of deadzones (places in the ocean where marine life cannot live) on continental shelves and in bays and estuaries. The modern ocean is losing oxygen at a similar rate to the just before major anoxic events in the Cretaceous Period about 90 million years ago.  These past oceanic anoxic events are useful partial analogs to understand deoxygenation in our oceans and its effect on marine life (the short version is it drives a lot of extinction).

I also study how life recovers after major mass extinction events, particularly the End Cretaceous mass extinction that killed the dinosaurs and 75% of life on Earth. That mass extinction was caused by an asteroid impact in the Gulf of Mexico. The impact caused particles to fly into the atmosphere, blocking the sun. Because of this, photosynthesis crashed, and everything went extinct in just a few years. This is probably the only major event in Earth history that happened faster than modern climate change, so it’s a useful analog to understand how ecosystems rebound after a rapid extinction event. We are not (yet) experiencing a sixth mass extinction today, but rates of extinction are undeniably high because of human activity. How the biosphere (the plants, animals, and various other life forms on Earth) will recovery once human disruption finally stops is an important thing to understand. Unfortunately, results from the past suggest that life will take millions of years to bounce back.

The best part of being a scientist, in my opinion, is working to solve problems that I find interesting (this is my main advice to aspiring scientists, too, find something that you think is interesting and that will hold your attention. There are lots of important things we don’t know and you don’t have to pick the highest profile one). The other best part of being a scientist is the opportunity to work in the field and go to sea and work with friends from all over the world to solve a problem. I got into geology because I wanted a job where I could be outside at least part of the time, but the chances to travel have surpassed all of my expectations.

Chris is currently a Research Associate at the University of Texas Institute for Geophysics. He was a member of a drilling expedition that recovered a core from the Chicxulub crater, where the asteroid that killed the dinosaurs hit. Chris and his team were featured in the NOVA documentary ‘Day the Dinosaurs Died’, which is freely available online here. To learn more about Chris and his science, you can follow him on Twitter @clowery806.