Here are some examples of our helium measurements in the Pacific Ocean. The map shows the location of two long WOCE sections, P17 and P19, relative to the Juan de Fuca Ridge (JdFR) and the East Pacific Rise (EPR). The JdFR and EPR are active volcanic ridges which are known to be sources of hydrothermal ³He in the deep Pacific. These helium data are reported in units of delta (³He)%, which is the percentage deviation of the helium isotope ratio from the ratio in air. To view the images of the helium data merely click on the appropriate link. There is also a plan view map of a large helium plume emanating from Loihi Seamount on the flanks of the Island of Hawaii.