New style logger (red arrow) imaged by TowCam on the R/V New Horizon cruise in M vent, EPR at 9? 50.6?N in May 2006. Data from this logger (recovered by Alvin in June 06) provide the first direct measurements of the impact of a volcanic eruption on hydrothermal vent fluid temperature (K. Von Damm, unpubl. data, 2006) and the correlation with microseismicity [Tolstoy et al., submitted]. (right) An old style logger being extracted from a vent with Jason2?s manipulator.