By Niya Shao, PhD student
To answer this question, scientific expeditions have traveled to the Svalbard Archipelago, home of the northernmost year-round settlement in the world, Langerbyen, since the 18th century. In March of 2024, I, followed those expeditions to join a field course at the University Centre in Svalbard.
During this course, we rode snowmobiles to the Slakbreen glacier, laid out 10 kilometers of geophone-attached cords, and set up explosives (dynamite!) to conduct active seismic surveys to evaluate the sedimentary structures below the glacier. Knowledge about geology structures in the sediment can be used to infer the past history of the glacier. More critical for my research are the sediment strength and water content underneath the glacier, which are the key to many glacial processes and control the rate of glacial motion. However, seismic surveys are complicated by how sound travels through the uppermost ice layer. We were able to process the signal from the dynamite explosions to show three distinct deep signals, possibly representing sediment layers and suggesting most of subglacial water was frozen at the time of the survey. However, we saw partially frozen melt water in the toe of the glacier. Our hope is to take repetitive seismic surveys to evaluate changes related to rising temperature.
To further evaluate the water content, we also used passive seismic surveys that recorded natural sounds, such as cracking ice and water flowing through the ice, and ground penetrating radar that showed us the thickness of the ice. These passive measurements and radar surveys helped interpret active seismic survey by bringing back data at higher resolution and showing possible locations of water and sediment within the ice.
Many dangers accompany arctic field work: blizzards occur rapidly, which could limit visibility to less than a few meters, polar bear are common, and at zero degrees Fahrenheit, frostbite is an ever-present possibility. To limit weather hazards, we always checked local conditions before leaving camp, wore protective suits, and carried protective flare guns, rifles, binoculars, emergency beacons, and more. Although the surrounding enormous white mountains made us feel small, we were empowered by our responsibilities to all on the field team.
I am now back in lively, and warm, Gainesville, with hurricane season looming. With my new and better understanding of geophysical survey techniques, fieldwork, and living conditions in the Arctic, where mean winter temperatures in Svalbard has risen 11-18 degrees Fahrenheit in the last 50 years, I have a better understanding of the different issues affecting people living in these two places. I also now recognized these issues stem from the same cause and raise universal questions: Could the teamwork spirit under the harsh Arctic conditions be extended globally? Could we take care of each other to save our living places under the changes in climate occurring now and in the future? I look forward to finding answers to these and other questions during the rest of my Ph.D. journey.