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Name Alias(es): 
MAR, 45 N
MGDS_FeatureID lowest in hierarchy: 
Vent Sites: 
Dian Cecht
The Fomorians
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Notes on Vent Field Description: "Irish-led VENTuRE scientific expedition aboard the national research vessel RV Celtic Explorer has discovered a previously uncharted field of hydrothermal vents along the mid-Atlantic ridge – the first to be explored north of the Azores"; InterRidge Email #18/2011 (25 August 2011); Wheeler et al. (2013): "This is the only high temperature hydrothermal vent known between the Azores and Iceland, in the North Atlantic and is located on a slow to ultraslow-spreading mid-ocean ridge uniquely situated on the 300 m high fault scarp of the eastern axial wall, 3.5 km from the axial volcanic ridge crest. Furthermore, the Moytirra vent field is, unusually for tectonically controlled hydrothermal vents systems, basalt hosted and perched midway up on the median valley wall and presumably heated by an off-axis magma chamber. The Moytirra vent field consists of an alignment of four sites of venting, three actively emitting “black smoke,”"; note Wheeler et al. (2013) has depth "2095 m" in text but figure indicates ~2900 m
Notes Relevant to Biology: "“Using the ROV’s high-definition video camera, we’ve watched unusual orange-bodied shrimp crawling around the chimneys, among clusters of tiny green limpets,”; Wheeler et al. (2013): "surfaces of the vent chimneys are occupied by aggregations of gastropods (Peltospira sp.) and populations of alvinocaridid shrimp (Mirocaris sp. with Rimicaris sp. also present). Other fauna present include bythograeid crabs (Segonzacia sp.) and zoarcid fish (Pachycara sp.), but bathymodiolin mussels and actinostolid anemones were not observed in the vent field. The discovery of the Moytirra vent field therefore expands the known latitudinal distributions of several vent-endemic genera in the north Atlantic, and reveals faunal affinities with vents south of the Azores rather than north of Iceland."
Year and How Discovered (if active, visual confirmation is listed first): 
2011 ROV Holland 1; 2008 plume only MAPRs, ROV Isis buoyant plume, but no visual confirmation
Discovery References (text): 
Wheeler, A. J., et al. (2013), Moytirra: Discovery of the first known deep-sea hydrothermal vent field on the slow-spreading Mid-Atlantic Ridge north of the Azores, Geochem. Geophys. Geosyst., 14, 4170–4184, doi:10.1002/ggge.20243.
(plume only) Searle et al. (2008) Structure and development of the axial volcanic ridge: Cruise JC24 to the Mid-Atlantic Ridge, 45°N. InterRidge News 17: 11-15.
[vents database version 1 had locations near this site as "Fe & Mn enriched sediments", citing Cronan, Can. J. Earth Sci., 9, 319- 323, 1972, and Grousset & Donard, Enrichments in Hg, Cd, As, and Sb in recent sediments of Azores-Iceland Ridge, Geo-Marine Letters, 4, 117-124, 1984].