FATE OF EVENT HYDROTHERMAL PLUMES ON THE JUAN-DE-FUCA RIDGE

Current meter moorings were deployed in August 1993 at the megaplume s ite of the June 1993 seismic event on the CoAxial segment of the Juan de Fuca Ridge and were recovered in April 1994. Record-averaged flow w as about 2 cm/s across axis, which is sufficiently large to advect plu mes off axis in a few days. During July two megaplumes (1800 m level) disappeared between repeated CTD rows. A deeper plume (2150 m) had a r elatively strong signature during August and extended southeastward in agreement with the observed flow. A CTD tow along the east flank of A xial Volcano did not locate remnants of the megaplumes but did find de eper plumes which could have come from off-axis advection from the CoA xial sources followed by southward advection along the east side of ri dge.