Spain_2025_Sarmiento_ICEFLAME

Voyage Schedule:

Mobilise at Punta Arenas 12 Jan 2025

Demobilise at Escudero Base 08 Feb 2025

Project Title:

impact of ICE-sheet retreat and geological controls on Fluid fLow dynAMics of the antarctic pEninsula continental margin (ICEFLAME)

Project Details:

Polar regions that have lost a significant mass of their ice sheets since the Last Glacial Maximum (LGM) are experiencing remarkable isostatic rebound. Rapid climatic changes in the Antarctic Peninsula over the past 50 years have led to the retreat and collapse of major ice shelves, which triggered additional post-LGM isostatic rebound. In the Antarctic Peninsula, the South Shetland Islands and adjacent continental shelves, isostatic uplift has clearly outpaced eustatic sea level rise. This area hosts significant gas hydrate accumulations, which might be affected by such isostatic rebound, as the gas hydrates are brought into new pressure conditions and out of their stability field. Recent long-term ocean warming could further affect the stability of such gas hydrate reservoirs. The main hypothesis of the ICEFLAME proposal is therefore that gas hydrates of the northern Antarctic Peninsula margin are unstable under present-day pressure and temperature conditions and they are currently dissociating. Consumption of methane contained in gas hydrates by microbial activity in both aerobic and anaerobic conditions within the sediment acts to prevent much of this greenhouse molecule from reaching the ocean and atmosphere. However, plumes of bubbles emanating from the seafloor above several gas hydrate provinces attest to a more complex relationship between subseafloor methane generation, storage and export to the ocean. ICEFLAME aims to study how fluid flow and gas hydrates of the Antarctic Peninsula margin respond to changes in pressure and temperature associated with Holocene to present uplift from isostatic rebound and temperature increase of bottom water masses. ICEFLAME aims to understand the entire hydrocarbon play of the Antarctic Peninsula: How hydrocarbon charged fluids migrate in the subsurface and are trapped in gas hydrates or emitted to the water column. Additionally, ICEFLAME aims to assess how the stress-state of marine sediments is evolving and how this affects the stability of the seafloor. To unravel these questions ICEFLAME proposes a geophysical/geological/geochemical approach based on data collected during a 30 days long cruise and reusing information available from several repositories. We anticipate the project results will have a high international impact, given the project will investigate changes in polar zones that affect the entire planet. The main outcome of ICEFLAME will be an assessment of the nature, volume and dynamics of the gas hydrates at the tip of the Antarctic Peninsula. Project ICEFLAME will also tackle fundamental processes that influence geological hazards on all continental margins.

Equipment Onboard:

• Acoustic and survey systems Echo sounder system Sub bottom profiler Magnetics
• Coring systems Gravity corer Multicorer Dredge
• Gephysics Seismic Systems Data acquisition Data recording Source
• Laboratory infrastructure Sample Handling
• CTD Nitrate Sensor Deep Suna V2 CTD SBE 9 Plus Temperature Sensor SBE 3P  Conductivity Sensor SBE 4C Dissolved Oxygen Sensor SBE 43 Altimeter PSA-916 Chlorophyll Fluorometer & Turbidity Meter WETLABS CDOM Fluorometer WETLABS Methane Sensor METS

Ship Fitted Equipment:

Acoustic “Gondola” with Multibeam

Parametric Echosounder Transducers

Single Beam (hydrographical)