Helium Isotope Laboratory

Research Activities

Helium emission concentrations over Loihi seamount.

Our research group is studying the effects of hydrothermal venting on the oceans at a variety of spatial and temporal scales. At the broadest scale, we are studying the circulation of the deep and intermediate waters of the Pacific Ocean. Specifically, we are using noble gas tracers, especially ³He, to map the patterns of oceanic circulation and mixing. Hydrothermal venting along the axis of the global midocean ridge system and from certain volcanic seamounts produces hydrothermal plumes in the deep ocean which are enriched in ³He relative to ambient ocean water. Because these plumes have localized source regions, their distribution can be used to trace patterns of circulation and mixing. This is especially true in the Pacific Ocean, where the spreading rate of the volcanic ridges is very high, resulting in a correspondingly high rate of helium injection.

Measurements of oceanic ³He from the World Ocean Circulation Experiment (WOCE) Hydrographic Program have added greatly to our knowledge of the distribution of hydrothermal plumes in the deep Pacific, thereby providing strong constraints on the deep circulation in certain areas. Our research group has measured deep helium on several WOCE Pacific sections, including P1 (TPS-47), P3 (TPS-24), P16, P17, and P19, as well as NOAA expeditions RITS-89 and CGC-91. We are also in the process of analyzing deep helium samples from WOCE lines P13 and P18.

• Helium Measurements in the Central Pacific Ocean
• Helium Measurements in the North Pacific Ocean

References

Lupton, J.E., Hydrothermal plumes: near and far field, in Seafloor Hydrothermal Systems: Physical, Chemical, Biological, and Geological Interactions, Edited by S. Humphris, R. Zierenberg, L. Mullineaux, and R. Thomson, Geophysical Monograph 91, American Geophysical Union, Washington, D.C., pp. 317-346, 1995.

Lupton, J.E., A far-field hydrothermal plume from Loihi Seamount, Science 272, 976-979, 1996.

Lupton, J.E., Hydrothermal ^helium plumes in the Pacific Ocean, J. Geophys. Res., 103(C8), 15,853–15,868

Staff

Links to Other WOCE Helium Data