Description: Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 142–157, doi:10.5670/oceanog.2012.12.

Description: Volcanic eruptions are important events in Earth's cycle of magma generation and crustal construction. Over durations of hours to years, eruptions produce new deposits of lava and/or fragmentary ejecta, transfer heat and magmatic volatiles from Earth's interior to the overlying air or seawater, and significantly modify the landscape and perturb local ecosystems. Today and through most of geological history, the greatest number and volume of volcanic eruptions on Earth have occurred in the deep ocean along mid-ocean ridges, near subduction zones, on oceanic plateaus, and on thousands of mid-plate seamounts. However, deep-sea eruptions (〉 500 m depth) are much more difficult to detect and observe than subaerial eruptions, so comparatively little is known about them. Great strides have been made in eruption detection, response speed, and observational detail since the first recognition of a deep submarine eruption at a mid-ocean ridge 25 years ago. Studies of ongoing or recent deep submarine eruptions reveal information about their sizes, durations, frequencies, styles, and environmental impacts. Ultimately, magma formation and accumulation in the upper mantle and crust, plus local tectonic stress fields, dictate when, where, and how often submarine eruptions occur, whereas eruption depth, magma composition, conditions of volatile segregation, and tectonic setting determine submarine eruption style.

Description: NSF-OCE 0937409 (KHR), OCE-0525863 and OCE-0732366 (DJF and SAS), 0725605 (WWC), OCE- 0751780 (ETB and RWE), OCE‐0138088 (MRP), OCE-0934278 (DAC), OCE-0623649 (RPD), and a David and Lucile Packard Foundation grant to MBARI (DAC and DWC).

Description: Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 89–93, doi:10.5670/oceanog.2012.06.

Description: Basalt lavas comprise the greatest volume of volcanic rocks on Earth, and most of them erupt along the world's mid-ocean ridges (MORs). These MOR basalts (MORBs) are generally thought to be relatively homogeneous in composition over large segments of the global ridge system (e.g., Klein, 2005). However, detailed sampling of two different regions on the northern East Pacific Rise (EPR) and extensive analysis of the samples show that fine-scale mapping and sampling of the ridge axis can reveal significant variations in lava chemistry on both small spatial and short temporal scales. The two most intensely sampled sites within the EPR Integrated Study Site (ISS) lie on and off axis between 9°17'N and 10°N, and from a wide region centered around 9°N where two segments of the EPR overlap (see Fornari et al., 2012, Figure 3, in this issue). The chemical composition of erupted lavas, similar to the genotype of an organism, can be used by igneous petrologists to trace the evolution of magmas from the mantle to the seafloor. The extensive and detailed geochemical studies at the EPR highlight how a thorough understanding of the variability in lava compositions on small spatial scales (i.e., between lava flows) and large spatial scales (i.e., from segment center to segment end and including discontinuities in the ridge crest) can be used in combination with seafloor photography, lava morphology, and bathymetry to provide insights into the magmatic system that drives volcanism and influences hydrothermal chemistry and biology at a fast-spreading MOR.

Description: Grants that supported EPR ISS field and laboratory studies for our research programs include: MRP: OCE-0138088, OCE-0819469, OCE-825265, OCE-638406, OCE-527077, OCE-535532; DJF: OCE-9819261, OCE-0525863, OCE-0838923, OCE-0096468, OCE-0732366, and OCE-0112737.

Description: Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 128–141, doi:10.5670/oceanog.2012.11.

Description: Submarine volcanic eruptions and intrusions construct new oceanic crust and build long chains of volcanic islands and vast submarine plateaus. Magmatic events are a primary agent for the transfer of heat, chemicals, and even microbes from the crust to the ocean, but the processes that control these transfers are poorly understood. The 1980s discovery that mid-ocean ridge eruptions are often associated with brief releases of immense volumes of hot fluids ("event plumes") spurred interest in methods for detecting the onset of eruptions or intrusions and for rapidly organizing seagoing response efforts. Since then, some 35 magmatic events have been recognized and responded to on mid-ocean ridges and at seamounts in both volcanic arc and intraplate settings. Field responses at mid-ocean ridges have found that event plumes occur over a wide range of eruption styles and sizes, and thus may be a common consequence of ridge eruptions. The source(s) of event plume fluids are still debated. Eruptions detected at ridges generally have high effusion rates and short durations (hours to days), whereas field responses at arc volcanic cones have found eruptions with very low effusion rates and durations on the scale of years. New approaches to the study of submarine magmatic events include the development of autonomous vehicles for detection and response, and the establishment of permanent seafloor observatories at likely future eruption sites.

Description: Support for these efforts came from the NOAA Vents Program and the National Science Foundation, primarily through its long-term funding of the RIDGE and Ridge 2000 Programs, including grants OCE-9812294 and OCE-0222069. SOSUS detection efforts were supported from 2006 to 2009 by the National Science Foundation, grant OCE-0623649.

Description: Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 12–17, doi:10.5670/oceanog.2012.01.

Description: Articles in this special issue of Oceanography represent a compendium of research that spans the disciplinary and thematic breadth of the National Science Foundation's Ridge 2000 Program, as well as its geographic focal points. The mid-ocean ridge (MOR) crest is where much of Earth's volcanism is focused and where most submarine volcanic activity occurs. If we could look down from space at our planet with the ocean drained, the MOR's topography and shape, along with its intervening fracture zones, would resemble the seams on a baseball, with the ocean basins dominating our planetary panorama. The volcanic seafloor is hidden beneath the green-blue waters of the world's ocean, yet therein lie fundamental clues to how our planet works and has evolved over billions of years, something that was not clearly understood 65 years ago—witness the following quote from H.H. Hess (1962) in his essay on "geopoetry" and commentary on J.H.F. Umbgrove's (1947) comprehensive summary of Earth and ocean history: The birth of the oceans is a matter of conjecture, the subsequent history is obscure, and the present structure is just beginning to be understood. Fascinating speculation on these subjects has been plentiful, but not much of it predating the last decade [the 1950s] holds water.

Description: This special issue was funded by a supplement to the Ridge 2000 Office grant at the Woods Hole Oceanographic Institution (NSF-OCE-0838923).

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Matabos, M., Barreyre, T., Juniper, S., Cannat, M., Kelley, D., Alfaro-Lucas, J., Chavagnac, V., Colaço, A., Escartin, J., Escobar, E., Fornari, D., Hasenclever, J., Huber, J., Laës-Huon, A., Lantéri, N., Levin, L., Mihaly, S., Mittelstaedt, E., Pradillon, F., Lantéri, N., Levin, L. A., Mihaly, S., Mittelstaedt, E., Pradillon, F., Sarradin, P-M., Sarrazin, J., Tomasi, B., Venkatesan, R., & Vic, C. Integrating Multidisciplinary Observations in Vent Environments (IMOVE): decadal progress in deep-sea observatories at hydrothermal vents. Frontiers in Marine Science, 9, (2022): 866422, https://doi.org/10.3389/fmars.2022.866422.

Description: The unique ecosystems and biodiversity associated with mid-ocean ridge (MOR) hydrothermal vent systems contrast sharply with surrounding deep-sea habitats, however both may be increasingly threatened by anthropogenic activity (e.g., mining activities at massive sulphide deposits). Climate change can alter the deep-sea through increased bottom temperatures, loss of oxygen, and modifications to deep water circulation. Despite the potential of these profound impacts, the mechanisms enabling these systems and their ecosystems to persist, function and respond to oceanic, crustal, and anthropogenic forces remain poorly understood. This is due primarily to technological challenges and difficulties in accessing, observing and monitoring the deep-sea. In this context, the development of deep-sea observatories in the 2000s focused on understanding the coupling between sub-surface flow and oceanic and crustal conditions, and how they influence biological processes. Deep-sea observatories provide long-term, multidisciplinary time-series data comprising repeated observations and sampling at temporal resolutions from seconds to decades, through a combination of cabled, wireless, remotely controlled, and autonomous measurement systems. The three existing vent observatories are located on the Juan de Fuca and Mid-Atlantic Ridges (Ocean Observing Initiative, Ocean Networks Canada and the European Multidisciplinary Seafloor and water column Observatory). These observatories promote stewardship by defining effective environmental monitoring including characterizing biological and environmental baseline states, discriminating changes from natural variations versus those from anthropogenic activities, and assessing degradation, resilience and recovery after disturbance. This highlights the potential of observatories as valuable tools for environmental impact assessment (EIA) in the context of climate change and other anthropogenic activities, primarily ocean mining. This paper provides a synthesis on scientific advancements enabled by the three observatories this last decade, and recommendations to support future studies through international collaboration and coordination. The proposed recommendations include: i) establishing common global scientific questions and identification of Essential Ocean Variables (EOVs) specific to MORs, ii) guidance towards the effective use of observatories to support and inform policies that can impact society, iii) strategies for observatory infrastructure development that will help standardize sensors, data formats and capabilities, and iv) future technology needs and common sampling approaches to answer today’s most urgent and timely questions.

Description: The first workshop in Bergen was additionally funded by the K.G. Jebsen Centre for Deep Sea Research and the University of Bergen. The second workshop was supported by ISblue project, Interdisciplinary graduate school for the blue planet (ANR-17-EURE-0015) and co-funded by a grant from the French government under the program “Investissements d’Avenir”. Additional funding was provided by Ifremer, and the départment du Finistère. The operation and maintenance of the EMSO-Azores observatory is funded by the by the EMSO-FR Research Infrastructure (MESR), which is managed by an Ifremer-CNRS collaboration. The operation and maintenance of the Endeavour observatory is funded by the Canada Foundation for Innovation’s Major Science Infrastructure program and the Department of Fisheries and Oceans (Canada). The operation and maintenance of the Axial Seamount observatory is funded by the National Science Foundation as part of the Ocean Observatories Initiative Regional Cabled Array. MM, JS and PMS acknowledge funding from the EU Horizon 2020 iAtlantic project (Grant Agreement No. 818123). AC was supported by the Operational Program AZORES 2020, through the Fund 01-0145-FEDER-1279 000140 “MarAZ Researchers: Consolidate a body of researchers in Marine Sciences in the Azores” of the European Union. She was also supported by FCT – Foundation for Science and Technology, I.P., under the project UIDB/05634/2020 and UIDP/05634/2020 and through the Regional Government of the Azores through the initiative to support the Research Centers of the University of the Azores and through the project M1.1.A/REEQ.CIENTÍFICO UI&D/2021/010.

Description: This paper is not subject to U.S. copyright. The definitive version was published in Journal of Volcanology and Geothermal Research 314 (2016): 142-155, doi:10.1016/j.jvolgeores.2015.07.037.

Description: Autonomous underwater vehicles were used to conduct a high-resolution water column survey of Lake Rotomahana using temperature, pH, turbidity, and oxidation–reduction potential (ORP) to identify active hydrothermal discharge zones within the lake. Five areas with active sublacustrine venting were identified: (1) the area of the historic Pink Terraces; (2) adjacent to the western shoreline subaerial “Steaming Cliffs,” boiling springs and geyser; (3) along the northern shoreline to the east of the Pink Terrace site; (4) the newly discovered Patiti hydrothermal system along the south margin of the 1886 Tarawera eruption rift zone; and (5) a location in the east basin (northeast of Patiti Island). The Pink Terrace hydrothermal system was active prior to the 1886 eruption of Mount Tarawera, but venting along the western shoreline, in the east basin, and the Patiti hydrothermal system appear to have been initiated in the aftermath of the eruption, similar to Waimangu Valley to the southwest. Different combinations of turbidity, pH anomalies (both positive and negative), and ORP responses suggest vent fluid compositions vary over short distances within the lake. The seasonal period of stratification limits vertical transport of heat to the surface layer and the hypolimnion temperature of Lake Rotomahana consequently increases with an average warming rate of ~ 0.010 °C/day due to both convective hydrothermal discharge and conductive geothermal heating. A sudden temperature increase occurred during our 2011 survey and was likely the response to an earthquake swarm just 11 days prior.

Description: Funding was provided by GNS Strategic Development Fund.