General Description and Scientific Significance

The IDOOS II Expedition, conducted in October 2024 aboard the AGS-61 Cabo de Hornos, marked the first recovery and maintenance operation of the infrastructure deployed during IDOOS I. The expedition successfully recovered two deep-ocean mooring lines that had continuously recorded data for an entire year in the depths of the Atacama Trench. 

In addition to data retrieval, the expedition included maintenance and recalibration of the instrumentation, redeployment of the moorings, and the deployment of a new autonomous lander, ensuring the continuity of one of the deepest long-term oceanographic observing programs in the Southeastern Pacific. 

Scientific Objectives

• Recover the deep-ocean moorings deployed in 2023.
• Retrieve the first continuous oceanographic data series from the Atacama Trench. 
• Perform maintenance and recalibration of the instrumentation.
• Redeploy the observing systems to continue long-term monitoring.
• Deploy a new autonomous lander for deep-sea observations and sampling.

Onboard Technology

• AGS-61 Cabo de Hornos research vessel.
• Deep-ocean moorings.
• Acoustic Doppler Current Profiler (ADCP) for current measurements.
• Temperature, pressure, and particle flux sensors.
• Acoustic release and recovery systems.
• Autonomous lander for hadal operations.
• CTD-Rosette system.

Participating Institutions

• Millennium Institute of Oceanography (IMO).
• Oceanographic Instrumentation Center (CIO).
• University of Concepción.
• Chilean Navy.
• SHOA.