Mothra Field

Kelley et al. (2001): "The 500-m-long Mothra hydrothermal field is the largest venting site in areal extent on the Endeavour segment of the Juan de Fuca Ridge near western valley wall. Within this field, there are at least five actively venting sulfide complexes, spaced 40 to 200 m apart along a trend of 020. The clusters are composed of multiple steep-sided pinnacles that rise up to 24m above the seafloor. Most of the sulfide structures are awash in diffusely venting fluids (30–200 C) that support rich and diverse macrofaunal and microbial communities. Isolated black smoker chimneys vent up to 320 C fluids"; Glickson et al. (2006): "Water column temperature anomalies were initially detected in 1986, and subsequent hydrocasts in 1988, 1991, and 1995 refined the position of the hydrothermal plume, leading to the field's discovery in 1996. In 1997 and 1998, the Edifice Rex sulfide recovery expedition mapped two sites of focused hydrothermal flow and collected four large sulfide chimneys from the central part of the field"; area of Canadian marine protected area. Kelley (2012): composed of six clusters of chimneys reaching up to 24 m in height, spaced ~600 m along strike and ~200 m across strike. >tens of active and inactive chimneys, typically tall, slender and lacking pronounced flanges, numerous sites of diffuse flow. Smokers not perturbed by 1999-2000 events though diffuse flow was affected. A centred position has been provided by Ocean Network Canada based on their observations.