Core values: the geoscientists searching for climate answers beneath the ocean floor

Surrounding the island of Hawai’i, buried in the seabed of the Pacific Ocean, are a series of ancient coral reefs preserved in fossil form. Over the course of 500,000 years, these reefs successively grew and drowned as the sea level rose, leaving behind a unique record of climate change over millennia.

Today, two geoscientists from the University of Leicester are working aboard the multipurpose vessel MMA Valour to try and unearth the hidden history within these preserved reefs. The two-month expedition expects to reveal new insights into the changes in sea levels and their impact on coral reefs, filling in the gaps in a half-a-million-year history of our planet’s changing climate.

Dr Marisa Rydzy from the School of Geography, Geology and the Environment has been on MMA Valour for over a month now. She is a member of the European Consortium for Ocean Research Drilling (ECORD) Science Operator (ESO), who organised this mission specific platform expedition as part of the International Ocean Discovery Program (IODP). She brings with her a background in petrophysics and experimental rock physics.

For Dr Rydzy, being part of expedition is a great adventure. “My excitement on a scale from 1 to 10? 12! Most of my research has been in clastic sediments. So, getting to dive (pun intended) into the field of corals and carbonates is fascinating, not to mention the thrill of working with a whole group of coral reef experts!

“I have been more seasick than I thought I would be... some queasiness aside though, it’s been good fun. The ship’s crew, the medic, the coring team, our ESO colleagues, and the science party members have all been lovely and the work is really interesting.”

The expedition aims to recover core samples from water depths between 134 and 1,155 meters at a maximum of twenty locations. A vital part of this work is the multi-sensor core logger (MSCL), a device that logs several physical properties along the fossilised corals, such as bulk density, magnetic susceptibility, and natural gamma radiation. 

Dr Rydzy and her Leicester colleague Dr Andrew McIntyre, who embarked the MMA Valour during a recent port call, have great expertise in using the MSCL. This is Dr McIntyre’s second expedition as part of IODP and says he is “honoured” to be working with a great team of enthusiastic scientists.

He says: “Seeing the seabed corer launch and deployed to the seafloor by a winch was a really cool moment and a very different style of coring than I have previously witnessed. We were fortunate to core the hundredth site of the Mission Specific Platform program within IODP. The milestone site was fun to be a part of and we look forward to the scientific discoveries to come from those cores!”

Dr Rydzy agrees. “Watching the seafloor corer being launched was definitively a highlight. It’s an impressive machine and a remarkable piece of technology. Also, when we got the first core on deck, that was a special moment.

While the seafloor sampling system is collecting core on seabed, the team has the opportunity to mull over their data, discuss science, and come up with new research ideas. “Slow and steady is the mantra here. So far, we have logged all the core that has been recovered and the MSCL data already shows some interesting features. With a few weeks left in the expedition, we are hoping that we will continue to make some interesting discoveries that can help unlock the history surrounding the drowned reefs of Hawaii.“

Life on board for Dr McIntyre and Dr Rydzy has been as different as day and night – literally! 

Dr McIntyre says: “I am on the night shift, so my typical day starts at around 23:00 with a quick breakfast before starting the 12-hour shift at midnight. It starts with our daily crossover catch-up with Marisa as she finishes her shift. Depending on progress with the coring, some shifts are busy with running cores on the MSCL and others are spent processing and analysing data. Most days we get the chance to capture the beautiful sunrises at around 6.30am. Before you know it the end of shift comes around at noon and crossover again with Marisa and the day shift.”

“Working and living offshore is fairly regimented.” Dr Rydzy adds. “You wake up, exercise (maybe), have breakfast, slip into your coveralls, work your 12-hour shift, have dinner, go to bed, read, and sleep. Rinse and repeat. Life becomes very simple. We don’t have to worry about cooking, cleaning, or laundry. All that is provided by the ship’s great staff. The only (non-work-related) decision we have to make is whether to have cake for breakfast, lunch, or dinner (or all three)." 

But life on board is not all about work and science. “When we are off shift, we sometimes have some fiercely competitive card game matches. Watching the amazing Hawaiian sunrises and sunsets during our lunch breaks also always remains a much-loved group activity here on board.”