Exploring the Future of Ice: Insights from the Irving Institute Faculty Seminar

On Friday, November 7th, the Irving Institute's Faculty Seminar attracted an audience of over 60 participants, both in-person and online, to explore the future of ice. This Seminar Series serves as a platform for faculty and researchers from across the campus to exchange insights on their ongoing projects related to energy and society. By organizing these monthly gatherings, the Institute aims to build a vibrant community that fosters interdisciplinary collaboration and uncovers new connections between diverse research endeavors.

The seminar spotlighted presentations from two distinguished Thayer scholars: Research Scientist Dr. Aleah Sommers and Assistant Professor Dr. Yoshihiro Nakayama. Their talks exemplified the spirit of collaboration that the Institute champions. Dr. Sommers highlighted her ongoing partnership with the Indian Institute of Science, an initiative strengthened by a formal collaboration agreement signed earlier this year. Midway through the session, Dartmouth AI Specialist Dr. Mash Rahman spontaneously expressed interest in exploring potential research collaborations with Dr. Sommers, further showcasing the seminar's role in inspiring collaborative opportunities.

Unraveling Glacier Dynamics and Flood Risks in the Himalayas

inline-image-aleah-sommers.jpg

Aleah Sommers, Research Scientist, Thayer School of Engineering (Photo by Andrila Hait Chakrabarti)

Research Scientist Aleah Sommers, PhD presented her work on "Understanding Himalayan glacier dynamics, future evolution, and floods" at the Irving Institute Faculty Seminar on November 7, 2025. Her talk underscored the direct societal impacts of glaciers, which are crucial for water resources but also pose significant flood risks. She highlighted that while polar ice sheets contribute to sea-level rise, mountain glaciers, particularly in the Himalayas, are vital for seasonal water supply, supporting economic development and daily living. A growing concern is the increase in glacier lake outburst floods as glaciers melt, leading to the formation of new lakes or the enlargement of existing ones, which can cause catastrophic damage downstream.

Dr. Sommers' research extensively focuses on subglacial hydrology—the study of water flowing beneath glaciers where they meet their bed. She explained that this subglacial water, when pressurized, can lubricate the glacier's base and even lift the ice, thereby influencing glacier sliding and overall dynamics. To investigate these complex interactions, Dr. Sommers developed and uses the SHAKTI subglacial hydrology model, which is coupled with the ice sheet and sea level system model (ISSM). She provided an example from Ladakh, India, where her modeling efforts demonstrated how subglacial hydrology influences seasonal changes in glacier velocity, including periods of acceleration in spring and deceleration in summer as efficient drainage channels develop.

During a recent field trip to a glacier in Ladakh, India, Dr. Sommers and her collaborators made intriguing observations. They learned about a lake associated with the glacier that had caused a major outburst flood in 2014 and had refilled to dangerous levels by 2024. However, the lake level appeared much lower in 2025 than the year before, and local downstream community members reported unusual water flow through the stream during the previous winter, suggesting a natural, gradual release from the lake, potentially preventing another catastrophic flood. This discovery raises critical questions about the mechanisms behind such natural mitigation and how these processes could inform better flood risk management. Dr. Sommers emphasized the ongoing efforts to model this unique lake drainage and analyze imagery to reconstruct its history, integrating diverse expertise to enhance understanding of Himalayan glacier systems.

The overarching goals of this research include predicting future changes in Himalayan glaciers, informing more robust monitoring systems, and developing improved early warning systems for floods. By focusing on specific regions like Ladakh, the project aims to derive general principles applicable globally, while also respecting cultural and environmental differences. Importantly, Dr. Sommers highlighted the commitment to strengthening international scientific collaborations, particularly with India, as a cornerstone for advancing this vital field of study and addressing the global challenges posed by changing glaciers.

Decoding Ice-Ocean Interactions in Antarctica and the Southern Ocean

inline-image-yoshihiro-nakayama.jpg

Yoshihiro Nakayama, Assistant Professor, Thayer School of Engineering (Photo by Andrila Hait Chakrabarti)

Professor Yoshihiro Nakayama, presented on "What is happening in the Southern Ocean and Antarctica?" His research delves into the complex interactions between ice and the ocean in these polar regions. Professor Nakayama shared insights drawn from his own experiences, such as scuba diving under sea ice in northern Japan, which visually demonstrated the intricate small-scale dynamics of water masses and ice melt. He underscored that his work not only investigates the process of ice melting but also the structural influence of the surrounding ocean, emphasizing the sharp gradients and distinct layers of water that define these cold environments.

A central theme of Professor Nakayama's presentation was the substantial ice loss occurring in Antarctica, particularly in regions like the Amundsen Sea, which contributes significantly to global sea-level rise. He explained that even slightly warmer ocean water can melt floating ice shelves from below, thereby thinning and weakening them, which in turn facilitates the faster flow of grounded ice into the ocean. Additionally, he discussed how sea ice formation drives ocean circulation through brine rejection, creating dense, saline water that sinks to form Antarctic Bottom Water. His group's methodology involves synthesizing observations and advanced models, with a special emphasis on leveraging historical data, including records dating back to the 1930s, to better understand long-term changes such as the freshening observed in the Ross Sea. Ultimately, his research aims to unravel how these dynamic processes impact global sea level and ocean circulation.

Watch the full seminar