Into the Quiet Zone: Marine Geophysics Students Explore Ancient Ocean Crust
Students Complete Research Cruise in Micronesia
Six graduate students from the EAS recently returned from a winter-break research cruise aboard the R/V Sikuliaq, part of a National Science Foundation-funded expedition to investigate the oldest linear magnetic anomalies in the world’s oceans. These features, known as the Jurassic Quiet Zone (JQZ), represent a region of low-amplitude magnetic anomalies thought to reflect a period of rapid geomagnetic reversals.
The cruise, designated SKQ202418S, departed Honolulu, Hawai‘i on December 13, 2024, and concluded in Pohnpei, Federated States of Micronesia, on January 7, 2025. Fieldwork was concentrated in the region between Anewetak and Pikinni (Bikini) atolls—locations historically known for mid-20th century nuclear testing.
The primary goal of the expedition was to collect multichannel seismic data to image the top of Jurassic oceanic crust or volcanic layers along survey lines that will later be used for deep magnetic profiling. The EAS students played an integral role in the research by standing watch in the electronic and seismic labs, documenting data acquisition, and processing both seismic and multibeam echosounder depth data.
In addition to their research contributions, the students earned academic credit through GEOL 6397: Selected Topics in Applied Geophysics – Marine Geophysics at Sea, taught by Dr. William Sager. Dr. Sager, a principal investigator on the project, has long been a leader in the study of oceanic crustal processes and magnetic anomalies.