In brief
Recent findings of tiny ice quakes beneath Greenland's surface offer a new understanding of how glaciers interact with impurities and contribute to global sea level rise.
When Andreas Fichtner lowered a fiber-optic cable into a borehole in Greenland's vast ice sheet in August 2022, he had no expectation of uncovering a groundbreaking phenomenon regarding glacier movement. Initially dismissing the data as mere "electronic noise," Dr. Fichtner, a seismology and wave physics professor at ETH Zurich, soon faced a startling revelation. As the field season neared its end, the research team was determined to utilize one last cable to explore the minute motions occurring in the ice as it flowed toward the sea. Their findings, detailed in the journal Science, have opened new questions about our understanding of Greenland and Antarctica's ice sheets and their contributions to rising sea levels. The fiber-optic cable detected an array of tiny "ice quakes," some registering reverberations hundreds of feet deep. Investigating further, Dr. Fichtner noted that these seismic occurrences often originated near impurities embedded within the ice — remnants of past volcanic events. The presence of these particles can weaken the ice structure, making it susceptible to cracking. As a result, the ice exhibits a unique pattern of sticking and slipping along these faults, generating the tiny seismic events captured by their instruments. This innovative research not only challenges long-held assumptions about glacier movement but also highlights the complex interplay of geological and environmental factors at play beneath Greenland’s icy surface. The quest for understanding ice dynamics continues, offering critical insights into global sea level rise linked to climate change.
