Response of the 9-10N EPR Hydrothermal Systems to Recent Volcanic Eruptions
Abstract
The Ridge2000 Integrated Study Site (ISS) on the East Pacific Rise (EPR), 9-10° north latitude was impacted by several volcanic eruptions in the months preceding April 2006. In June 2006 during the RESET06 cruise (AT15-6) we used the DSV Alvin to collect samples from the hydrothermal system at this site from M Vent in the north (9°°50.7'N) to L Vent in the south (9°46.3'N). This is the area that was also impacted by the 1991/2 eruption(s). Samples were collected from six high temperature vents, all of which had been sampled prior to the 2006 eruptive event(s), and two areas of low temperature fluid flow. In most cases the venting high temperature fluids collected were exiting from sulfide chimneys that predated this most recent event, in contrast to what was observed in most cases in 1991. However, all of the structures sampled were now venting fluids with chlorinities below seawater, even if they had been venting high chlorinity fluids when last sampled in November 2004. M vent is no longer venting any hydrothermal fluids. Maximum H2S values are less than those in 1991 (≤40 vs ≤110 mmoles/kg). Minimum Cl concentrations measured in 2006 are also not as low as those measured in 1991. Whether this is a fundamental difference between the two eruptions or a result of the timing of the sampling points relative to the timing of the eruption(s) is not yet clear.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFM.V13C..02V
- Keywords:
-
- 3614 Mid-oceanic ridge processes (1032;
- 8416);
- 8424 Hydrothermal systems (0450;
- 1034;
- 3017;
- 3616;
- 4832;
- 8135)