How we look kilometers below the Antarctic ice sheet | Dustin Schroeder

TL;DR

In this TED Talk, the speaker discusses the challenges of estimating sea level rise and proposes using radar technology and earth-science education to improve accuracy.

Transcript

I'm a radio glaciologist. That means that I use radar to study glaciers and ice sheets. And like most glaciologists right now, I'm working on the problem of estimating how much the ice is going to contribute to sea level rise in the future. So today, I want to talk to you about why it's so hard to put good numbers on sea level rise, and why I belie... Read More

Key Insights

• 🌏 The uncertainty in predicting sea level rise is already large, and the collapse of the West Antarctic Ice Sheet could lead to even higher numbers, emphasizing the need for accurate and comprehensive observations.
• 🛰️ Satellite observations are limited in providing detailed information about the processes and conditions beneath kilometers of ice, highlighting the challenge of studying the Antarctic ice sheet.
• 📡 Airborne ice-penetrating radar is a crucial tool in studying ice sheets, providing valuable insights into the structure and history of the ice.
• 🔬 Digitizing old radar observations from 50 years ago allows for comparisons with contemporary conditions, but it is still a snapshot and does not capture the variation in annual or seasonal changes. ⏰ The current methods of observation either provide spatial coverage or temporal coverage, but not both simultaneously, necessitating the development of new ways to observe the ice sheet.
• 💡 Using existing radio signals, such as those from the sun, could potentially offer a low-cost alternative to traditional radar systems, allowing for extensive network deployment on the ice sheet.
• 🌍 Advances in software-defined radio, rapid fabrication, and the maker movement enable the development of custom, low-cost radar sensors optimized for specific problems, facilitating a new era of observation capabilities.
• 🎓 The study of sea level rise provides an opportunity to teach and mentor brilliant students who have the potential to solve many of the world's challenges, leveraging their talent and passion to make a positive impact.

Questions & Answers

Q: Why is it difficult to estimate how much ice will contribute to sea level rise in the future?

Estimating the contribution of ice to sea level rise is challenging because it requires models that include all the processes, conditions, and physics involved in a potential collapse of ice sheets. These processes and conditions are difficult to observe as they occur beneath kilometers of ice, which satellites are unable to detect. Additionally, observations are needed on a large spatial and temporal scale, spanning the entire continent of Antarctica and over different time periods.

Q: How do radar systems help study ice sheets?

Radar systems, specifically airborne ice-penetrating radar, are the main tools used to study the inside of ice sheets. Radar signals are transmitted down into the ice, and the echoes that return provide information about what is happening inside and beneath the ice sheet. This allows scientists to create radargrams, which are vertical profiles through the ice that reveal the surface, bedrock, and layers within the ice sheet. Radar is considered the perfect tool for studying ice sheets because ice is an ideal target for radar.

Q: What challenges are faced in observing the subsurface of ice sheets?

Observing the subsurface of ice sheets is challenging due to the large scale in both space and time. In terms of space, Antarctica is a continent with distinct subsurface regions, similar to the Rocky Mountains, Everglades, and Great Lakes regions in North America. In terms of time, ice sheets not only evolve over centuries and millennia but also change over shorter periods of years and days. The observations needed must cover a large space and be conducted continuously over time, which is currently difficult to achieve.

Q: What progress has been made in obtaining observations of ice sheet changes over time?

Recent progress has been made in obtaining observations of ice sheet changes over time. Traditional airborne radar sounding provides good spatial coverage, while ground-based radar systems offer continuous observation at a single spot. However, neither method provides both spatial and temporal coverage simultaneously. Efforts are being made to analyze historical radar data collected using optical film, which offers a snapshot of the ice sheet at a specific point in time. However, continuous observations at the annual or seasonal scale are still limited.

Q: How is radio technology being utilized to improve ice sheet observations?

Radio technology, specifically the radio emissions from the sun, is being explored as a potential radar signal for ice sheet observations. By detecting the reflection of the sun off the surface of the ocean, which is similar to detecting the reflection off the bottom of an ice sheet, scientists hope to apply the same measurement principle in Antarctica. This approach has shown promise in preliminary field tests. Low-cost sensors and the advancements in software-defined radio and rapid fabrication techniques make it feasible to deploy networks of sensors on an ice sheet for imaging, revolutionizing ice sheet observations.

Q: How is the collaboration between engineers and scientists helping advance ice sheet observations?

The collaboration between engineers and scientists is helping advance ice sheet observations by breaking down barriers and allowing for the development of custom radar sensors optimized for each specific problem. Recent advancements in software-defined radio, rapid fabrication, and the maker movement enable teams, even young undergraduates, to build prototype radar systems at low cost and high performance. This shift in approach allows for more tailored and efficient observation methods, transforming the way ice sheets are studied.

Q: What motivates the speaker to work on estimating sea level rise?

The speaker is motivated to work on estimating sea level rise because of the opportunity it provides to teach and mentor highly talented students. The speaker believes that teams of driven and passionate young people have the potential to solve the world's challenges, and providing observations for estimating sea level rise is just one of the many problems they can and will solve. The importance of the issue itself, concerning the role of the cryosphere in sea level rise, further adds to the speaker's motivation.

Summary & Key Takeaways

• The speaker is a radio glaciologist who uses radar to study glaciers and ice sheets.

• They discuss the problem of estimating how much the ice will contribute to sea level rise in the future and why it is difficult to put accurate numbers on it.

• They propose changing the way radar technology is used and integrating earth science education in order to improve the accuracy of these estimates.