LSU College of Science researchers travel all over the world, from Iceland, to Madagascar, to caves in Indiana, to the South China Sea, in pursuit of answers to the questions that intrigue them and keep them up at night. What keeps Chang Liu up at night are big questions about the history of our oceans and their deep sea sediments. Where did these sediments come from? How has land and sea distribution changed over time? What can that tell us about the future landscapes of our planet?
Chang Liu is a Ph.D. candidate in Geology & Geophysics at LSU. Chang recently returned from a nine-week research cruise with the IODP (International Ocean Discovery Program) in the South China Sea, where he joined assistant professor Patricia Persaud. IODP is one of the world’s largest research entities in the earth sciences. Chang was one of the sedimentologists onboard the JOIDES Resolution and collaborated with geoscientists from around the world while on the cruise.
Join us as Chang gives us peek of his journey at sea and his research at LSU!
LSU College of Science: What is your background? What inspired you to go into science as a career?
Chang: I am a Ph.D. candidate in LSU’s Department of Geology & Geophysics. My research focuses on deep sea sediments. I explore where these sediments come from, how fast the sediment flux changes and how the source of these sediments has varied throughout geological history (on the scale of millions of years). In the lab, I’m currently measuring samples collected by JOIDES Resolution, a scientific drilling vessel operated by the International Ocean Discovery Program (IODP). This lab work will tell me about the sediments’ geochemical features. I hope to develop a more complete story of how the environment in the region where we collected these sediments has evolved, for example how the land and sea distribution has changed and how monsoons in the region have evolved.
What attracts me to geology research is that I want answers to big scientific questions such as, when did our current rivers form? How are their flow patterns changing? How can we prove these changes from samples collected in the deep sea? How might these changes affect people’s lives in the future? These might seem like simple questions, but to get reliable scientific answers is quite complicated.
LSU College of Science: What does your typical day look like?
Chang: I wake up around 7 a.m. (could be later during the weekends!) and I usually hit the gym in the morning. Then I come to my office in Howe-Russell and I start the work day by responding to or sending emails. Then I typically read several research papers related to my own research, followed by some writing. I will take coffee breaks with my friends once or twice a day depending on how sleepy I am! I often walk around and talk to colleagues about research and exchange ideas.
If I have lab work to do, I typically do that in the afternoon. Finally, I watch a new horror movie every Tuesday night with friends!
LSU College of Science: Can you tell us more about your summer field experience? Why did you go into the field? What research questions are you or were you trying to answer?
Chang: I was very lucky to get involved with IODP drillings as an onboard scientist this summer. I spent nine weeks working on the JOIDES Resolution vessel, which possesses the most advanced technology in the world for deep sea research. The entire vessel is a huge research lab. In total, 30 scientists around the world are selected to join an IODP expedition based on their research interests.
The cruise I was on this summer aimed to investigate the rifting mechanism [a tectonic process] of the largest marginal basin in Southeast Asia, called the South China Sea basin, which formed around 65 million years ago. Currently two types of rifting types have been discovered. One is found with abundant volcanic activities, while the other one is found with metamorphic rock, meaning with poor magmatic activities. My Ph.D. research focuses on this basin, so I was really excited to join this expedition and collect more data that will allow me to expand my research project.
My Ph.D. research could tell us more about what happened during the opening of this basin over 24 million years ago, such as how sediments moved into this natural sink and what type of weather occurred in this area in the past, by looking at deep sea sediments. Prior to 24 million years ago, these processes are poorly understood due to the limited accessibility to decent drilling samples. Most of the records older than 24 Ma have been eroded or weathered on the continent. Therefore, sediments in the deep sea provide us an ideal venue to explore the geological history of this basin in a much older time frame.
LSU College of Science: What have you found so far?
Chang: I am looking forward to analyzing sandstone from our samples, which contains heavy minerals like zircon. One of the research projects I’m involved with, which is led by Dr. Peter Clift, is exploring where the sediments in this basin came from. For example, grains that were delivered by river will be coarser and possibly have a higher porosity, whereas lake sediments will be finer with more organic material. I also expect to find some strongly weathered sediments, which may be evidence that the regional monsoon system actually initiated earlier than 24 million years ago, contrary to our current understanding. Understanding where sediments in this region came from is important for both oil and gas exploration as well as paleoenvironmental reconstruction of the region.
During our latest expedition onboard the JOIDES Resolution, we analyzed four different sites. The coring of our deepest site went to 700 meters below the seafloor, or about 5000 meters below the sea water level. We retrieved and sampled both rocks and sediment. We found very fresh basalt and some greenish metamorphic rock called serpentine. We also found a very thick layer of sandstone at bottom of one site, which is what I want to explore further. The answers to my research questions need more geochemical analysis in the future, but so far I have a good feeling about them. I think that on this expedition we retrieved some deep sediments that have never been reached before.
I learned a lot of new skills during this cruise. I learned how to make a smear slide and identify sediment under a microscope, as well how to identify certain microfossils. I learned about these things previously from my classes and books, but it is a completely different feeling seeing them in a real sample.
LSU College of Science: What did you bring with you into the field? What does it LOOK like to be in the field, for you? What do/did you eat, wear, etc.?
Chang: I brought a suitcase of clothes and two books onboard the ship, nothing more. JOIDES Resolution has everything you need to live for two months!
The ship is 150 meters long and around 30 meters wide. It has six floors. The bottom part is a computer room where we have satellite internet, with a signal strong enough to send/receive emails and download papers, but very slow for browsing Facebook or using Skype. The vessel also has a gym and a movie room where we could relax after work. The ship has a huge collection of movies and TV shows!
Our cabins, cafeteria and laundry room are in the middle floors of the vessel. A conference room, lab and chief-scientist’s office take up the upper three floors. In the center of the ship is the drilling floor, where all the sea sediment cores come from.
There was only sea water all around us. There were some big bluish fishes swimming around the ship during the first few days. As we moved into deeper waters, they disappeared. Dolphins were the only neighbors we saw every day. They liked to swim around us.
All crew members were divided into two groups, namely the dayshift and the nightshift. The day shift started at 12 p.m. and ended at 12 a.m. I was in the nightshift, which took over every day from 12 a.m. to 12 p.m. There were coffee breaks every three hours, and a meal every six hours. It is very interesting in the cafeteria, because you would be eating breakfast while other crew members were having their dinner! Everyone says “good morning” when we see each other, even if it is 11 p.m., because it is morning for the nightshift! It totally messes up your biological clock. But a single IODP Expedition costs roughly $200,000 to $300,000 per day, so the best way to use each 24 hours effectively is to divide the crew into a nightshift and dayshift.
Philippian crew members helped us with food and laundry. We had steak and chicken almost every day. The chefs cooked Asian cuisines too, sometimes. We had a BBQ on the deck at noon every Sunday. There were also two coffee machines and tea pot in the Cafe to keep everyone awake.
The laundry service was fantastic. All we needed to do was put our dirty clothes in a bag and drop it off by our cabin door before going to bed. The crew in charge of the laundry room picked them up, washed and dried them for us. They folded them very well and put them back by the door. They finished everything fast, making sure you had clean clothes to wear for the next day. I could have brought just one pair of clothes with me!
I really appreciated everyone’s wonderful work. We had a great time on the ship, no need to worry about anything while living here!
LSU College of Science: What was your favorite part about this field experience? What was most challenging?
Chang: My favorite part of this expedition was watching the sun rise every morning. I was on the nightshift, so one of the rewards for waking up at midnight was that I could watch the sunrise. It really cleared my mind and reminded me that each day was a new day. It’s amazing how the sun only took about two minutes to rise completely from sea level. The clouds looked like they were being burned. It was very beautiful.
The most challenging part of the expedition was the sea sickness. The first three days were the most difficult for me. I felt dizzy and could not concentrate on my microscope work. One of the other scientists had to stay in bed for three days straight on account of sea sickness.
Another challenge for me was waking up at midnight and attending our crossover meeting (a 15-minute meeting between the dayshift and nightshift). It became extremely exhausting about halfway through the expedition.
LSU College of Science: What was the most surprising or interesting thing that happened during your field experience?
Chang: The most surprising thing was that we got a chance to watch the entire process of drilling and what happens on the seafloor beneath thousands of meters of seawater. When we were drilling the third site, we needed to drop down a camera to observe the previous drilling location. While the camera was being moved down from the top of the sea to the seafloor, the entire shift of scientists surrounded the monitor to watch the process. There were a lot of strange and beautiful things I had never seen before. We saw an animal about the size of a bicycle tire spinning around the camera, like it was dancing. We also observed several strangely shaped crabs on the seafloor, shaped in ways to withstand the extremely high pressure at this depth. It was quite entertaining and surprising to see these mysterious parts of the ocean that we have not yet explored fully.
The most interesting thing we did during the cruise was drop a bag of 8 oz foam cups to the seafloor along with the camera. Each one of us drew a picture on the cup. When the cups were brought back to the lab, they had shrunk considerably! All the pictures and words were concentrated, and even looked much better.
LSU College of Science: What was most rewarding aspect of this field experience for you?
Chang: Besides learning a lot of new professional skills, I developed many new social connections. Each IODP expedition acts like a small United Nations. We had scientists from all over the world. Each one has a different way of thinking and communicating. My goal in the next two years is to continue my research in Germany, so the opportunity to get to know several scientists from Germany really helped me better understand their research work process there and the different types of software they use.
LSU College of Science: What's next?
Chang: I am trying to graduate with my Ph.D. this semester and I am looking for a postdoctoral research fellowship. I have applied to one in Germany. They could provide me with the lab facilities and funding to continue analysis of my samples from this expedition. My samples will be decarbonated and processed on a ICP-OES, which will give me several geochemical element concentrations. I will then put these data into my proxies to create a conceptual model.
LSU College of Science: What is your favorite thing about studying geology at LSU?
Chang: I love the gym at LSU, and our new tiger! The LSU Lakes is also one of my favorite spots.
LSU College of Science: What are your hobbies?
Chang: I like playing basketball and hiking.
LSU College of Science: What advice do you have for high school or first-year students interested in geology at LSU?
Chang: Use LSU as a resource for your future. There are so many excellent faculty members and so much cool research happening here. You don’t have to be a graduate student to get involved. New ideas and hard work are always in need. I have known many undergraduates who have done great research collaborating with graduate students and professors. LSU Geology student Allison Barbato just received a GSA grant for her undergraduate research at LSU.
LSU College of Science: What do you wish you'd known or done differently as a freshman in college?
Chang: I completed my undergraduate degree in China, and the system is a little bit different there. We had our professional major determined as a freshman. But I wish I could have gotten into research work and started my GRE preparation earlier. This would have saved me a lot of time.
LSU College of Science: What are your future plans? Where do you see yourself in 5 years?
Chang: I hope to work as a postdoc for a few years and then become a professor. I definitely hope to sail again with JOIDES Resolution to collect more new and interesting data! I also hope to sail with CHIKYU from Japan, which serves as another major scientific drilling vessel and is capable of reaching a deeper subsurface world than JOIDES Resolution. Hopefully, I can also plan my own expedition as a chief scientist. All I need is more papers and more experience in the academia world!