@article {Larson2015,
	title = {{Stealth export of hydrogen and methane from a low temperature serpentinization system}},
	journal = {Deep-Sea Research Part II: Topical Studies in Oceanography},
	volume = {121},
	year = {2015},
	pages = {233{\textendash}245},
	abstract = {Chemical input to the deep sea from hydrothermal systems is a globally distributed phenomenon. Hydrothermal discharge is one of the primary mechanisms by which the Earth{\textquoteright}s interior processes manifest themselves at the Earth{\textquoteright}s surface, and it provides a source of energy for autotrophic processes by microbes that are too deep to capitalize on sunlight. Much is known about the water-column signature of this discharge from high-temperature mid-ocean Ridge (MOR) environments and their neighboring low-temperature counterparts. Hydrothermal discharge farther away from the ridge, however, has garnered less attention, owing in part to the difficulty in finding this style of venting, which eludes methods of detection that work well for high-temperature {\textquoteleft}black smoker{\textquoteright}-type venting. Here we present a case study of the plume from one such {\textquoteleft}invisible{\textquoteright} off-axis environment, The Lost City, with an emphasis on the dissolved volatile content of the hydrothermal plume. Serpentinization and abiotic organic synthesis generate significant concentrations of H2 and CH4 in vent fluid, but these species are unevenly transported to the overlying plume, which itself appears to be a composite of two different sources. A concentrated vent cluster on the talus slope channels fluid through at least eight chimneys, producing a water-column plume with the highest observed concentrations of CH4 in the field. In contrast, a saddle in the topography leading up to a carbonate cap hosts broadly distributed, nearly invisible venting apparent only in its water-column signals of redox potential and dissolved gas content, including the highest observed plume H2. After normalizing H2 and CH4 to the 3He background-corrected anomaly (3He$Δ$) to account for mixing and relative amount of mantle input, it appears that, while a minimum of 60{\%} of CH4 is transported out of the system, greater than 90{\%} of the H2 is consumed in the subsurface prior to venting. The exception to this pattern occurs in the plume originating from the area dubbed Chaff Beach, in which somewhat more than 10{\%} of the original H2 remains, indicating that this otherwise unremarkable plume, and others like it, may represent a significant source of H2 to the deep sea.},
	keywords = {AUV ABE (Autonomous Benthic Explorer), HOV Alvin (Human Occupied Vehicle)},
	doi = {10.1016/j.dsr2.2015.05.007},
	author = {Larson, B I and Lang, S Q and Lilley, M D and Olson, E J and Lupton, J E and Nakamura, K and Buck, N J}
}
@article {ISI:000345545100011,
	title = {{The Anatomy of a Buried Submarine Hydrothermal System, Clark Volcano, Kermadec Arc, New Zealand}},
	journal = {ECONOMIC GEOLOGY},
	volume = {109},
	number = {8},
	year = {2014},
	month = {dec},
	pages = {2261{\textendash}2292},
	type = {Article},
	abstract = {Clark volcano of the Kermadec arc, northeast of New Zealand, is a large stratovolcano comprised of two coalescing volcanic cones; an apparently younger, more coherent, twin-peaked edifice to the northwest and a relatively older, more degraded and tectonized cone to the southeast. High-resolution water column surveys show an active hydrothermal system at the summit of the NW cone largely along a ridge spur connecting the two peaks, with activity also noted at the head of scarps related to sector collapse. Clark is the only known cone volcano along the Kermadec arc to host sulfide mineralization. Volcano-scale gravity and magnetic surveys over Clark show that it is highly magnetized, and that a strong gravity gradient exists between the two edifices. Modeling suggests that a crustal-scale fault lies between these two edifices, with thinner crust beneath the NW cone. Locations of regional earthquake epicenters show a southwest-northeast trend bisecting the two Clark cones, striking northeastward into Tangaroa volcano. Detailed mapping of magnetics above the NW cone summit shows a highly magnetized ring structure 350 m below the summit that is not apparent in the bathymetry; we believe this structure represents the top of a caldera. Oblate zones of low (weak) magnetization caused by hydrothermal fluid upflow, here termed burn holes, form a pattern in the regional magnetization resembling Swiss cheese. Presumably older burn holes occupy the inner margin of the ring structure and show no signs of hydrothermal activity, while younger burn holes are coincident with active venting on the summit. A combination of mineralogy, geochemistry, and seafloor mapping of the NW cone shows that hydrothermal activity today is largely manifest by widespread diffuse venting, with temperatures ranging between 56 degrees and 106 degrees C. Numerous, small ({\textless}= 30 cm high) chimneys populate the summit area, with one site host to the similar to 7-m-tall {\textquoteleft}{\textquoteleft}Twin Towers{\{}{\textquoteright}{\textquoteright}{\}} chimneys with maximum vent fluid temperatures of 221 degrees C (pH 4.9), consistent with delta S-34(anhydrite-pyrite) values indicating formation temperatures of similar to 228 degrees to 249 degrees C. Mineralization is dominated by pyrite-marcasite-barite-anhydrite. Radiometric dating using the Ra-228/Ra-226 and Ra-226/Ba methods shows active chimneys to be {\textless}20 with most {\textless}2 years old. However, the chimneys at Clark show evidence for mixing with, and remobilizing of, barite as old as 19,000 years. This is consistent with Nd and Sr isotope compositions of Clark chimney and sulfate crust samples that indicate mixing of similar to 40{\%} seawater with a vent fluid derived from low K lavas. Similarly, REE data show the hydrothermal fluids have interacted with a plagioclase-rich source rock. A holistic approach to the study of the Clark hydrothermal system has revealed a two-stage process whereby a caldera-forming volcanic event preceded a later cone-building event. This ensured a protracted (at least 20 ka yrs) history of hydrothermal activity and associated mineral deposition. If we assume at least 200-m-high walls for the postulated (buried) caldera, then hydrothermal fluids would have exited the seafloor 20 ka years ago at least 550 m deeper than they do today, with fluid discharge temperatures potentially much hotter (similar to 350 degrees C). Subsequent to caldera infilling, relatively porous volcaniclastic and other units making up the cone acted as largescale filters, enabling ascending hydrothermal fluids to boil and mix with seawater subseafloor, effectively removing the metals (including remobilized Cu) in solution before they reached the seafloor. This has implications for estimates for the metal inventory of seafloor hydrothermal systems pertaining to arc hydrothermal systems.},
	keywords = {AUV ABE (Autonomous Benthic Explorer), AUV Sentry (Autonomous Underwater Vehicle)},
	issn = {0361-0128},
	author = {de Ronde, C E J and Walker, S L and Ditchburn, R G and Tontini, F Caratori and Hannington, M D and Merle, S G and Timm, C and Handler, M R and Wysoczanski, R J and Dekov, V M and Kamenov, G D and Baker, E T and Embley, R W and Lupton, J E and Stoffers, P}
}
@article {Embley2014,
	title = {{Eruptive modes and hiatus of volcanism at West Mata seamount, NE Lau basin: 1996{\textendash}2012}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {15},
	number = {10},
	year = {2014},
	pages = {4093{\textendash}4115},
	abstract = {We present multiple lines of evidence for years to decade-long changes in the location and character of volcanic activity at West Mata seamount in the NE Lau basin over a 16 year period, and a hiatus in summit eruptions from early 2011 to at least September 2012. Boninite lava and pyroclasts were observed erupting from its summit in 2009, and hydroacoustic data from a succession of hydrophones moored nearby show near-continuous eruptive activity from January 2009 to early 2011. Successive differencing of seven multibeam bathymetric surveys of the volcano made in the 1996{\textendash}2012 period reveals a pattern of extended constructional volcanism on the summit and northwest flank punctuated by eruptions along the volcano{\textquoteright}s WSW rift zone (WSWRZ). Away from the summit, the volumetrically largest eruption during the observational period occurred between May 2010 and November 2011 at \~{}2920 m depth near the base of the WSWRZ. The (nearly) equally long ENE rift zone did not experience any volcanic activity during the 1996{\textendash}2012 period. The cessation of summit volcanism recorded on the moored hydrophone was accompanied or followed by the formation of a small summit crater and a landslide on the eastern flank. Water column sensors, analysis of gas samples in the overlying hydrothermal plume and dives with a remotely operated vehicle in September 2012 confirmed that the summit eruption had ceased. Based on the historical eruption rates calculated using the bathymetric differencing technique, the volcano could be as young as several thousand years.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	doi = {10.1002/2014GC005387},
	author = {Embley, R W and Merle, S G and Baker, E T and Rubin, K H and Lupton, J E and Resing, J A and Dziak, R P and Lilley, M D and Chadwick, W W and Shank, T M and Greene, R and Walker, S L and Haxel, J H and Olson, E J and Baumberger, T}
}
@article {Baumberger2014,
	title = {{Understanding a submarine eruption through time series hydrothermal plume sampling of dissolved and particulate constituents: West Mata, 2008-2012}},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {15},
	number = {12},
	year = {2014},
	pages = {4631{\textendash}4650},
	abstract = {Four cruises between 2008 and 2012 monitored the continuing eruption of West Mata volcano in the NE Lau Basin as it produced plumes of chemically altered water above its summit. Although large enrichments in He-3, CO2, Fe, and Mn were observed in the plumes, the most notable enrichment was that of H-2, which reached concentrations as high as 14,843 nM. Strongly enriched H-2 concentrations in the water column result from reactions between seawater or magmatic water and extremely hot rocks. In 2008, the observation of elevated H-2 concentrations in the water column above West Mata pointed to vigorous ongoing eruptions at the volcano{\textquoteright}s summit. The eruption was confirmed by visual observations made by the ROV Jason 2 in 2009 and demonstrated that H-2 measurements are a vital instrument to detect ongoing volcanic eruptions at the seafloor. Elevated H-2 in 2010 showed that the eruption was ongoing, although at a reduced level given a maximum H-2 concentration of 4410 nM. In 2012, H-2 levels in the water column declined significantly, to a maximum of only 7 nM, consistent with visual observations from the Quest-4000 ROV that found no evidence of an ongoing volcanic eruption. Methane behaved independently of other measured gases and its concentrations in the hydrothermal plume were very low. We attribute its minimal enrichments to a mixture of mantle carbon reduced to CH4 and biological CH4 from diffuse flow sites. This study demonstrates that ongoing submarine volcanic eruptions are characterized by high dissolved H-2 concentrations present in the overlying water column.},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	doi = {10.1002/2014GC005460},
	author = {Baumberger, T and Lilley, M D and Resing, J A and Lupton, J E and Baker, E T and Butterfield, D A and Olson, E J and Fruh-Green, G L}
}
@article {Chadwick2010,
	title = {{Northwest Rota-1 Seamount}},
	journal = {Oceanography},
	volume = {23},
	number = {1},
	year = {2010},
	month = {mar},
	pages = {182{\textendash}183},
	abstract = {Northwest Rota-1 Seamount is the first place on Earth where a submarine volcanic eruption was witnessed in 2004, and, remarkably, it appears that the volcano has been erupting continuously ever since. NW Rota-1 is located {\~{}} 100 km north of Guam in the western Pacific, within the newly designated Mariana Trench Marine National Monument (http://www.fws.gov/marianastrenchmarinemonument). With a summit depth of 520 m, it is a symmetrical cone of basaltic andesite composition (Figure 1) formed in the subduction zone setting of the Mariana volcanic arc. It was identified as a site of particular interest in 2003 when sampling of its overlying hydrothermal plume showed very high magmatic volatile input (Resing et al., 2007). Consequently, it was one of several seamounts targeted for dives with a remotely operated vehicle the following year. During these dives, an actively erupting vent was discovered at a depth of 550 m; lava, fluid, and gas samples were collected; and colonies of shrimp, limpets, and crabs (some of them new species) were found living in the volcano summit{\textquoteright}s harsh conditions (Embley et al., 2006; Lim{\'e}n et al., 2006).},
	issn = {1042-8275},
	doi = {10.5670/oceanog.2010.82},
	author = {Chadwick, W W and Embley, R W and Baker, E T and Resing, J A and Lupton, J E and Cashman, K V and Dziak, R P and Tunnicliffe, V and Butterfield, D A and Tamura, Y}
}
@article {Walker2008a,
	title = {{Eruption-fed particle plumes and volcaniclastic deposits at a submarine volcano: NW Rota-1, Mariana Arc}},
	journal = {Journal of Geophysical Research},
	volume = {113},
	year = {2008},
	pages = {B08S11},
	keywords = {ROV Jason (Remotely Operated Vehicle)},
	issn = {0148-0227},
	doi = {10.1029/2007JB005441},
	url = {http://dx.doi.org/10.1029/2007JB005441},
	author = {Walker, S L and Baker, E T and Resing, J A and Chadwick, W W and Lebon, G T and Lupton, J E and Merle, S G}
}
@article {Embley2007,
	title = {{Exploring the submarine ring of fire: Mariana Arc-Western Pacific}},
	journal = {Oceanography},
	volume = {20},
	number = {4},
	year = {2007},
	pages = {69{\textendash}80},
	keywords = {HOV Alvin (Human Occupied Vehicle), ROV Jason (Remotely Operated Vehicle)},
	issn = {1042-8275},
	doi = {10.5670/oceanog.2007.07},
	author = {Embley, R W and Baker, E T and Butterfield, D A and Chadwick, W W and Lupton, J E and Resing, J A and de Ronde, C E J and Nakamura, K I and Tunnicliffe, V and Dower, J F and Merle, S G}
}
@article {Lilley2003,
	title = {{Magmatic events can produce rapid changes in hydrothermal vent chemistry}},
	journal = {Nature},
	volume = {422},
	number = {6934},
	year = {2003},
	pages = {878{\textendash}881},
	keywords = {HOV Alvin (Human Occupied Vehicle), ROV Jason (Remotely Operated Vehicle)},
	issn = {0028-0836},
	doi = {10.1038/nature01569},
	url = {http://dx.doi.org/10.1038/nature01569},
	author = {Lilley, M D and Butterfield, D A and Lupton, J E and Olson, E J}
}
@inbook {Lupton1995,
	title = {{Hydrothermal plumes: Near and far afield}},
	booktitle = {Seafloor Hydrothermal Systems: Physical, Chemical, Biological, and Geochemical Interactions},
	series = {Geophysical Monograph},
	number = {91},
	year = {1995},
	pages = {317{\textendash}346},
	publisher = {American Geophysical Union},
	organization = {American Geophysical Union},
	address = {Washington, D.C.},
	isbn = {0-87590-048-8},
	author = {Lupton, J E},
	editor = {Humphris, S E}
}
@article {Massoth1995,
	title = {{Observations of manganese and iron at the CoAxial seafloor eruption site, Juan de Fuca Ridge}},
	journal = {Geophysical Research Letters},
	volume = {22},
	number = {2},
	year = {1995},
	pages = {151{\textendash}154},
	issn = {0094-8276},
	doi = {10.1029/94GL02662},
	url = {http://dx.doi.org/10.1029/94GL02662},
	author = {Massoth, G J and Baker, E T and Feely, R A and Butterfield, D A and Embley, R W and Lupton, J E and Thomson, R E and Cannon, G A}
}
@article {Massoth1994,
	title = {{Temporal and spatial variability of hydrothermal manganese and iron at Cleft segment, Juan de Fuca Ridge}},
	journal = {Journal of Geophysical Research},
	volume = {99},
	number = {B3},
	year = {1994},
	pages = {4905{\textendash}4923},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0148-0227},
	doi = {10.1029/93JB02799},
	url = {http://dx.doi.org/10.1029/93JB02799},
	author = {Massoth, G J and Baker, E T and Lupton, J E and Feely, R A and Butterfield, D A and Von Damm, K L and Roe, K K and Lebon, G T}
}
@article {Lupton1993,
	title = {{Chemical and physical diversity of hydrothermal plumes along the East Pacific Rise, 8 degrees 45{\textquoteright} N to 11 degrees 50{\textquoteright} N}},
	journal = {Geophysical Research Letters},
	volume = {20},
	number = {24},
	year = {1993},
	pages = {2913{\textendash}2916},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0094-8276},
	doi = {10.1029/93GL00906},
	url = {http://dx.doi.org/10.1029/93GL00906},
	author = {Lupton, J E and Baker, E T and Mottl, M J and Sansone, F J and Wheat, C G and Resing, J A and Massoth, G J and Measures, C I and Feely, R A}
}
@article {Lilley1992,
	title = {{Volatiles in the 9N hydrothermal system: a comparison of 1991 and 1992 data}},
	journal = {EOS, Transactions, American Geophysical Union},
	volume = {73},
	number = {43 (Fall Meeting Suppl.)},
	year = {1992},
	pages = {524},
	issn = {0096-3941},
	author = {Lilley, M D and Olson, E J and Lupton, J E and Von Damm, K L}
}
@article {Embley1988,
	title = {{Submersible observation of the {\textquoteright}megaplume{\textquoteright} areas: Southern Juan de Fuca Ridge}},
	journal = {EOS, Transactions, American Geophysical Union},
	volume = {69},
	year = {1988},
	pages = {1483},
	issn = {0096-3941},
	author = {Embley, R W and Hammond, S and Murphy, K M and Fox, C G and Appelgate, B and Massoth, G J and Feely, R A and Baker, E T and Gendron, J and Lebon, G and Butterfield, D A and Coughlin, B and Lupton, J E and Jonnason, I and Perfit, M R and Cowen, J P and Tunnicliffe, V and Trivett, D A}
}
@article {Lupton1980,
	title = {{Helium-3 and manganese at the 21 degrees N East Pacific Rise hydrothermal site}},
	journal = {Earth and Planetary Science Letters},
	volume = {50},
	number = {1},
	year = {1980},
	pages = {115{\textendash}127},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0012-821X},
	doi = {10.1016/0012-821X(80)90123-5},
	url = {http://dx.doi.org/10.1016/0012-821X(80)90123-5},
	author = {Lupton, J E and Klinkhammer, G P and Normark, W R and Haymon, R and Macdonald, K C and Weiss, R F and Craig, H}
}
