New Curtin University research has revealed that the Ninetyeast Ridge ­— the Earth’s longest straight underwater mountain chain ­— formed through a different process than previously believed.

Stretching 5000km along the Indian Ocean’s 90-degree east longitude and nearly matching the length of North America’s Rocky Mountains, the ridge offers crucial new insights into the movement of the Earth’s tectonic plates.

Dr. Sofia Sheikh from the SETI Institute led a study that sheds new light on how pulsar signals—the spinning remnants of massive stars—distort as they travel through space. This study, published in The Astrophysical Journal, was performed by a multi-year cohort of undergraduate researchers in the Penn State branch of the Pulsar Search Collaboratory student club. Maura McLaughlin, Chair, Eberly Distinguished Professor of Physics and Astronomy, West Virginia University, created the Pulsar Search Collaboratory to engage high schoolers and undergraduates in pulsar science, and she helped facilitate access to the data used in this study. Using archival data from the Arecibo Observatory, the student team found patterns that show how pulsar signals change as they move through the interstellar medium (ISM), the gas and dust that fills the space between stars. The team measured scintillation bandwidths for 23 pulsars, including new data for six pulsars not previously studied. The results showed that in almost all cases, measured bandwidths were higher than predictions by widely used models of the galaxy, highlighting a need for updates to current ISM density models.

“This work demonstrates the value of large, archived datasets,” said Dr. Sofia Sheikh, SETI Institute researcher and lead author. “Even years after the Arecibo Observatory's collapse, its data continues to unlock critical information that can advance our understanding of the galaxy and enhance our ability to study phenomena like gravitational waves.”