45 research outputs found
New frontiers in ocean exploration: the E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2019 field season
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Raineault, N.A., and J. Flanders, eds. (2020). New frontiers in ocean exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2019 field season. Oceanography 33(1), supplement, 122 pp., https://doi.org/10.5670/oceanog.2020.supplement.01.New Frontiers in Ocean Exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2019 Field Season is the tenth consecutive supplement on ocean exploration to accompany Oceanography. These booklets provide details about the innovative technologies deployed to investigate the seafloor and water column and explain how telepresence can both convey the excitement of ocean exploration to global audiences and allow scientists as well as the public on shore to participate in expeditions in real time. The supplements also describe the variety of educational programs the Ocean Exploration Trust, the NOAA Office of Ocean Exploration and Research, and the Schmidt Ocean Institute support in conjunction with schools, museums, visitors centers, and aquariums, as well as internships that bring high school students, undergraduates, graduate students, teachers, and artists on board ships. Through these supplements, we have explored the geology, chemistry, biology, and archaeology of parts of the global ocean and seas. We hope you enjoy this booklet and share it widely.Support for this publication is provided by the Ocean Exploration Trust, the NOAA Office of Ocean Exploration and Research, the National Marine Sanctuary Foundation, and the Schmidt Ocean Institute
Correction of Bathymetric Survey Artifacts Resulting from Apparent Wave-Induced Vertical Position of an AUV
Recent increases in the capability and reliability of autonomous underwater vehicles (AUVs) have provided the opportunity to conduct bathymetric seafloor surveys in shallow water (\u3c 50 m). Unfortunately, surveys of this water depth may contain artifacts induced by large amplitude wave motion at the surface. The artifacts occur when an onboard pressure sensor determines the depth of the AUV. Waves overhead induce small pressure fluctuations at depth, which modulate the AUVâs pressure sensor output without causing actual vertical movement of the AUV. Since bathymetric measurements are made with respect to the AUVâs depth, these pressure fluctuations, in turn, modulate the measurement of the seafloor. The result is a periodic across-track, vertical offset of the seafloor profile (similar to a heave artifact sometimes common in surface vessel surveys). In this paper we describe our experience with the âGaviaâ model AUV (Hafmynd EHF, Iceland) in a recent bathymetric survey during which wave action overhead induced such an artifact with a peak-to-peak amplitude as large as 1 meter. A method for removing the artifact as well as recommendations for modifications to the sonar, INS and AUV to mitigate the effect in the future are provided
Exploration of Eratosthenes Seamount â A continental fragment being forced down an oceanic trench
Conducting Efficient Remote Science and Planning Operations for Ocean Exploration Using Exploration Ground Data Systems (xGDS)
NASA Ames Exploration Ground Data Systems (xGDS) supports rapid scientific decision making by synchronizing information in time and space, including video and still images, scientific instrument data, and science and operations notes in geographic and temporal context. We have deployed xGDS at multiple NASA field analog missions over the past decade. In the last two years, we have participated in SUBSEA, a multi-institution collaborative project*. SUBSEA used the research ship E/V Nautilus along with its two remotely operated vehicles (ROVs), Hercules and Argus, to explore deep ocean volcanic vents as an analog for ocean worlds (e.g. Enceladus). This work allowed us to compare the existing oceanographic operations methods and technologies used for ocean exploration with corresponding tools and approaches developed and used at NASA. In the first year of SUBSEA we observed existing remote science operations from the Inner Space Center (ISC)**. In the second year, we deployed xGDS at ISC to complement existing capabilities with xGDS tools designed to support remote Nautilus science operations from the ISC. During operations, video, ROV position and instrument telemetry were streamed from the ship to the ISC. As the science team watched dive operations, they could annotate the data with observations that were relevant to their work domain. Later, the team members could review the data at their own pace to collaboratively develop a dive plan for the next day, which had to be delivered on a fixed daily schedule. The opportunity to compare operations under different conditions enabled us to make several key observations about conducting remote science and planning operations efficiently: (i) Reviewing data collaboratively and interactively with temporal and spatial context was critical for the remote science teams ability to plan dive operations on the Nautilus. (ii) Science team members were actively engaged with the remote dive operations because they could interact with the collected data and visualize it as they desired. (iii) Being able to replay past events at accelerated speeds, and jump to points in time and spaced based on search results, provided efficient access to critical points of interest in a massive volume of data, so the remote science team could deliver plans on time. * SUBSEA (Systematic Underwater Biogeochemical Science and Exploration Analog) is a multi-institution collaboration supported by NASA, NOAAs Office of Exploration Research (OER), the Ocean Exploration Trust (OET) and the University of Rhode Islands Graduate School of Oceanography (GSO)
New Insights into the Age and Origin of Two Small Cretaceous Seamount Chains Proximal to the Northwestern Hawaiian Ridge
The Northwestern Hawaiian Ridge is an age-progressive volcanic chain sourced from the Hawaiian mantle plume. Proximal to the Northwestern Hawaiian Ridge are several clusters of smaller seamounts and ridges with limited age constraints and unknown geodynamic origins. This study presents new bathymetric data and 40Ar/39Ar age determinations from lava flow samples recovered by remotely operated vehicle (ROV) from two eastâwest-trending chains of seamounts that lie north of the PĆ«hÄhonu and Mokumanamana volcanoes. The previously unexplored Naifeh Chain (28°48âČN,167°48âČW) and Plumeria Chain (25°36âČN, 164°35âČW) contain five volcanic structures each, including three guyots in the Naifeh Chain. New 40Ar/39Ar age determinations indicate that the Naifeh Chain formed ca. 88 Ma and the Plumeria Chain ca. 85 Ma. The Cretaceous ages, coupled with a perpendicular orientation of the seamounts relative to absolute Pacific plate motion at that time, eliminate either a Miocene Hawaiian volcanic arch or Cretaceous mantle-plume origin. The seamounts lie on oceanic crust that is modeled to be 10â15 Ma older than the corresponding seamounts. Here, two models are put forth to explain the origin of these enigmatic seamount chains as well as the similar nearby Mendelssohn Seamounts. (1) Diffuse lithospheric extension results in the formation of these seamounts until the initiation of the Kula-Pacific spreading center in the north at 84â79 Ma, which alleviates the tension. (2) Shear-driven upwelling of enriched mantle material beneath young oceanic lithosphere results in an age-progressive seamount track that is approximately perpendicular to the spreading ridge. Here we show that all sampled seamounts proximal to the Northwestern Hawaiian Ridge are intraplate in nature, but their formations can be attributed to both plume and plate processes
SUBSEA 2019 Expedition to the Gorda Ridge
The SUBSEA (Systematic Underwater Biogeochemical Science and Exploration Analog) program blends ocean exploration with âocean worldsâ research, along with NASA analog and work studies research, to address science, science operations, and technology knowledge gaps related to the exploration of our solar system. The science group researches venting fluids at isolated seamounts and spreading ridges in the Pacific Ocean as analog environments to putative volcanically hosted hydrothermal systems on other âocean worldsâ (defined as places in the outer solar system that could possess subsurface oceans). The science operations research group studies E/V Nautilus architecture, distributed teams, communication, and lowlatency telerobotics. The technology research group provided Exploration Ground Data Systems (xGDS) software to the shore team to support the integration and visualization of diverse data products during the cruise
Deep-Sea Exploration of the US Gulf of Mexico with NOAA Ship Okeanos Explorer
Oceanography articles are licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately (e.g., authors, Oceanography, volume number, issue number, page number[s], figure number[s], and DOI for the article), provide a link to the Creative Commons license, and indicate the changes that were made to the original content
Characterization of deep-sea benthic invertebrate megafauna of the Galapagos Islands
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Salinas-de-LeĂłn, P., MartĂ-Puig, P., Buglass, S., ArnĂ©s-UrgellĂ©s, C., Rastoin-Laplane, E., Creemers, M., Cairns, S., Fisher, C., O'Hara, T., Ott, B., Raineault, N. A., Reiswig, H., Rouse, G., Rowley, S., Shank, T. M., Suarez, J., Watling, L., Wicksten, M. K., & Marsh, L. Characterization of deep-sea benthic invertebrate megafauna of the Galapagos Islands. Scientific Reports, 10(1), (2020): 13894, doi:10.1038/s41598-020-70744-1.The deep sea represents the largest and least explored biome on the planet. Despite the iconic status of the Galapagos Islands and being considered one of the most pristine locations on earth, the deep-sea benthic ecosystems of the archipelago are virtually unexplored in comparison to their shallow-water counterparts. In 2015, we embarked on a multi-disciplinary scientific expedition to conduct the first systematic characterization of deep-sea benthic invertebrate communities of the Galapagos, across a range of habitats. We explored seven sites to depths of over 3,300 m using a two-part Remotely Operated Vehicle (ROV) system aboard the E/V Nautilus, and collected 90 biological specimens that were preserved and sent to experts around the world for analysis. Of those, 30 taxa were determined to be undescribed and new to science, including members of five new genera (2 sponges and 3 cnidarians). We also systematically analysed image frame grabs from over 85 h of ROV footage to investigate patterns of species diversity and document the presence of a range of underwater communities between depths of 290 and 3,373 m, including cold-water coral communities, extensive glass sponge and octocoral gardens, and soft-sediment faunal communities. This characterization of Galapagos deep-sea benthic invertebrate megafauna across a range of ecosystems represents a first step to study future changes that may result from anthropogenic impacts to the planetâs climate and oceans, and informed the creation of fully protected deep-water areas in the Galapagos Marine Reserve that may help preserve these unique communities in our changing planet.We are thankful to the Ocean Exploration Trust as well as the pilots and crew aboard the E/V Nautilus during cruise NA064 for their assistance in sample collection and exploration using the Hercules ROV. Thank you to the NOAA Office of Exploration and Research for funding the E/V Nautilus Exploration Program (NA15OAR0110220). Further acknowledgements and thanks go out to the Charles Darwin Foundation and the Galapagos National Park Directorate for their collaboration and assistance in the exploration of the Galapagos Platform conducted under research permits PC-26â15 & PC-45-15. We also gratefully recognize the Government of Ecuador via the Ecuadorian Navy for permission to operate in their territorial waters. This research was supported by a grant from the Helmsley Charitable Trust and the Gordon and Betty Moore Foundation. This publication is contribution number 2354 of the Charles Darwin Foundation for the Galapagos Islands
Effects of bulkheads on estuarine beach swash zone processes and characteristics
This thesis combines the study of geomorphic effects of beach topography, sediment characteristics, and transport with physical processes of waves, swash, and reflected energies to evaluate the effects of bulkheads on estuarine beaches. I hypothesize that the truncation of a beach by a bulkhead will (1) concentrate and increase turbulence directly seaward of the structure increasing sediment activation depth; (2) create interference and patterns of swash/wave and reflected energy interactions, increasing the topographic variability of the foreshore; and (3) increase turbulent energies enough to remove finer grained sand. Measurements of topographic variability, sediment activation depth, and net change were made over 21 tidal cycles on the foreshore at two wooden sheet pile bulkheads and a control site 45 m south of the bulkheads at Fortescue, New Jersey. Sediment cores were taken seaward of the bulkhead and at equivalent elevations on the control site to the depth of sediment activation. A video record was taken of swash and waves interacting with the bulkhead. The main conclusions are that since the swash and waves are precluded from migrating higher up the foreshore with the tide, the increased concentration of incident and reflected energies at bulkheads more than doubles the depth of sediment activation directly seaward, increasing the potential for sediment transport under higher energy conditions. Though no significant net surface change occurred seaward of the bulkheads, there are more frequent erosional/depositional cycles. The bulkheaded beaches have a more undulatory profile and a steeper slope within 0.5 to 1.5 m of the structure. The surface sediment on the bulkheaded beaches have a smaller amount of coarse sand and granules, although this may be an artifact of horseshoe crab burrowing on the control site. The type of bulkhead construction influences processes and beach response. One bulkhead that has buttress pilings on the bayward side has a steeper beach out to a greater distance (1.5 m) and smaller depth of sediment activation than the planar bulkhead due to sediment accumulation between the buttresses, which broke up the reflected energy. The 8.58 m long beach enclave between the two bulkheads has characteristics similar to bulkhead sites.M.S.Includes bibliographical references (p. 87-91)
Coastal bluffs in the Seal Harbor quadrangle, Maine
Maine Geological Survey, Open-File Map 05-21.https://digitalmaine.com/mgs_maps/1409/thumbnail.jp