What researchers are learning as they drill into Antarctica's 'Doomsday Glacier'

Thwaites Glacier Expedition: Data Collection & Challenges

Key Concepts:

• Thwaites Glacier (Doomsday Glacier): The widest glacier in the world, located in West Antarctica, with a high potential to contribute to significant sea level rise due to its instability and rapid melting.
• Grounding Line: The point where a glacier transitions from resting on land to floating on the sea. This is a critical area for understanding ice melt.
• Crevasse: A deep fissure in a glacier, often filled with air or water, posing a challenge to drilling operations.
• Salinity, Temperature, Current: Key parameters being measured in the seawater beneath the glacier to understand the mechanisms driving melt.
• Amundsen Sea: The sea bordering West Antarctica where warm currents are impacting the Thwaites Glacier.

Glacier Dynamics & Importance of Research

The expedition focuses on the Thwaites Glacier, often referred to as the “Doomsday Glacier” due to its potential to raise global sea levels by approximately 2.5 feet. This is a significant amount, especially when compared to the combined contribution of all other glaciers, which totals around 10 feet. Scientists are concerned because Thwaites is melting at a rate “orders of magnitude” faster than neighboring glaciers. The primary goal of the research is to understand why this glacier is melting so rapidly and to improve predictive models for future sea level rise.

Drilling Methodology & Technical Challenges

The core of the expedition involves drilling a 3,000-foot-deep hole through the glacier at the grounding line – the point where the ice transitions from land to sea. This is achieved using a hot water drill, requiring a substantial amount of thermal energy. The process involves:

1. Snow Collection: A team of 10 researchers manually shovels approximately 20 tons of snow into containers.
2. Water Production: Three generators power six heaters to melt the snow into water heated to 194 degrees Fahrenheit.
3. Drilling: The hot water is pumped through a black hose lowered into the glacier.
4. Instrument Deployment: Three spools are utilized: a black spool for the hot water drill, an orange spool for instruments not requiring real-time data transmission (like cameras), and a silver spool with coaxial cable for instruments needing continuous data relay to the surface.
5. Long-Term Monitoring: A tower structure will be left in place, extending through the glacier to the Amundsen Sea, to provide continuous, real-time data on temperature, salinity, and currents.

Currently, the team is facing a challenge: encountering a crevasse – an open cavern approximately 20-30 feet below the surface. This unexpected obstacle complicates the drilling process, requiring adjustments to ensure the drill hose remains stable and instruments can connect properly to the hole at the cavern’s base. This situation highlights the dynamic and unpredictable nature of the glacier.

Data Collection & Analysis

The instruments deployed through the drilled hole will measure several critical parameters:

• Salinity: The salt content of the seawater, indicating the source and mixing of water masses.
• Temperature: The water temperature, crucial for understanding the rate of melting. The water at 3,000 feet is already above freezing.
• Current: The speed and direction of the water currents, influencing the delivery of warm water to the glacier’s base.
• Sedimentary Picture: Analysis of sediment layers to reconstruct the glacier’s history and past melt events.

Climate Change Connection & Warm Water Intrusion

Miles O’Brien explains that the accelerated melting of Thwaites is linked to climate change-induced shifts in wind patterns around Antarctica. These changes have allowed warmer currents from the Amundsen Sea to intrude beneath the glacier, accelerating its melt from below. The research aims to quantify the extent of this warm water intrusion and its impact on the glacier’s stability.

Timeline & Logistical Constraints

The team is operating under a tight deadline. The research ship is scheduled to depart for New Zealand on February 7th, leaving approximately three days for drilling and data collection. Fuel availability for the heaters is also a limiting factor.

Environmental Conditions

The expedition is taking place in extremely cold conditions, with temperatures in the low 20s Fahrenheit. However, the wind coming off the ice is particularly harsh and penetrating, requiring substantial protective gear.

Notable Quote:

“Thwaites is sort of a keystone which holds [other glaciers] back. And this glacier alone represents about 2.5 feet of sea level rise all over the world.” – Miles O’Brien, emphasizing the disproportionate impact of the Thwaites Glacier.

Synthesis & Conclusion

The expedition to the Thwaites Glacier represents a critical effort to understand the dynamics of a rapidly changing and potentially catastrophic climate feature. The challenges encountered during the drilling process underscore the complexity of working in such a dynamic environment. The data collected will be vital for refining climate models and predicting future sea level rise, ultimately informing strategies for mitigating the impacts of climate change. The team’s success in overcoming the crevasse obstacle and completing their data collection within the tight timeframe will be crucial for advancing our understanding of this “Doomsday Glacier.”