Investigation of in Situ Surface Plasmon Resonance Spectroscopy for Environmental Monitoring in and around Deep-Sea Hydrothermal Vents

Abstract

We have developed a fiber optic Surface Plasmon Resonance (SPR) sensor capable of continuous in situ and real-time monitoring of physical or chemical properties in and around deep-sea hydrothermal vents. The spectroscopic sensor system was deployed on three Alvin cruises to hydrothermal fields in the eastern Pacific: cruise AT11-20 to the East Pacific Rise (EPR) and cruises AT11-31 and AT15-09 to the Juan de Fuca Ridge. The SPR-based sensor was integrated with a thermocouple employed to measure the densities of hydrothermal vent fluid and seawater surrounding the vent. The system was battery powered and placed in a pressure vessel capable of operating six kilometers below the ocean surface in and around hydrothermal vents. Results show the potential of in situ SPR analysis for monitoring in and around hydrothermal vents, including the ability to characterize spatial gradients of the dissolved hydrocarbons and mixing of vent fluid.

Keywords:

• Refractive index
• Salinity
• Sensors

Acknowledgments

The present address for Jeffrey Cramer is the US Naval Research Laboratory, Washington, DC. The present address for Tina Battaglia is Procter and Gamble, Boston, MA. The present address for James A. Jordan is US Geospatial Intelligence Agency, Washington, DC. The present address for Soame N. Banerji is Merck, NJ. The present address for Wei Peng is Dalian University, China.

Marv Lilley and Debbie Kelley were the chief scientists on the first two Alvin dive cruises (AT11-20, and AT11-31) and the last cruise (AT15-09), respectively. We are grateful to Marv Lilley for insight and discussion during the cruises. The authors especially thank the captain and crew of the R/V Atlantis and the pilots of the Alvin for their helpful collaboration. This work was supported by the NSF grant OCE 0119999.