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2. US Atlantic Margin Gas Hydrates

Author

Ruppel, Carolyn D., Shedd, William, Miller, Nathaniel C., Kluesner, Jared, Frye, Matthew, Hutchinson, Deborah, Mienert, Jürgen, editor, Berndt, Christian, editor, Tréhu, Anne M., editor, Camerlenghi, Angelo, editor, and Liu, Char-Shine, editor

Published
2022
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4. Limited contribution of ancient methane to surface waters of the U.S. Beaufort Sea shelf

Author

Sparrow, Katy J, Kessler, John D, Southon, John R, Garcia-Tigreros, Fenix, Schreiner, Kathryn M, Ruppel, Carolyn D, Miller, John B, Lehman, Scott J, and Xu, Xiaomei

Subjects
Earth Sciences, Oceanography, Geology, Climate Action
Abstract

In response to warming climate, methane can be released to Arctic Ocean sediment and waters from thawing subsea permafrost and decomposing methane hydrates. However, it is unknown whether methane derived from this sediment storehouse of frozen ancient carbon reaches the atmosphere. We quantified the fraction of methane derived from ancient sources in shelf waters of the U.S. Beaufort Sea, a region that has both permafrost and methane hydrates and is experiencing significant warming. Although the radiocarbon-methane analyses indicate that ancient carbon is being mobilized and emitted as methane into shelf bottom waters, surprisingly, we find that methane in surface waters is principally derived from modern-aged carbon. We report that at and beyond approximately the 30-m isobath, ancient sources that dominate in deep waters contribute, at most, 10 ± 3% of the surface water methane. These results suggest that even if there is a heightened liberation of ancient carbon-sourced methane as climate change proceeds, oceanic oxidation and dispersion processes can strongly limit its emission to the atmosphere.

Published
2018

6. Sponsored Projects : NOAA’s Office of Ocean Exploration and Research

Author

Valette-Silver, Nathalie, Cantelas, Frank, Beaverson, Chris, Netburn, Amanda, Jefferson, Yvette, Woodford, Joyce, Hammond, Stephen, Pomponi, Shirley, Reed, John, Voss, Joshua, Hanisak, Dennis, Diaz, M. Cristina, David, Andrew, Drummond, Felicia, González-Díaz, Patricia, López, Linnet Busutil, Martínez-Daranas, Beatriz, Rojas, Dorka Cobián, Bright, John, Green, Russell, Keogh, Kelly, Ho, Bert, Embley, Robert, Merle, Susan, Raineault, Nicole A., Gee, Lindsay, Ruppel, Carolyn, Demopoulos, Amanda W.J., Prouty, Nancy, Canonico, Gabrielle, Bohan, Margot, Nizinski, Martha, Adams, Caitlin, McNeil, Craig, D’Asaro, Eric, Reed, Andrew, Altabet, Mark A., and Bourbonnais, Annie

Published
2018

16. AUTOBIOGRAPHICAL SKETCHES OF WOMEN IN OCEANOGRAPHY

Author

Delaney, Peggy, Abrantes, Fatima, Alexander, Vera, Alldredge, Alice L., Almogi-Labin, Ahuva, Alonso, Belén, Anand, Pallavi, Ates, Sibel Bargu, Bauch, Dorothea, Bell, Robin E., Benitez-Nelson, Claudia, Benoit-Bird, Kelly, Bergamaschi, Dorothy Eden, Bernhard, Joan M., Billups, Katharina, Bronk, Deborah A., Campbell, Lisa, Canuel, Elizabeth A., Carbotte, Suzanne, Cessi, Paola, Chang, Grace C., Chase, Zanna, Chereskin, Teresa, Chiba, Sanae, Chisholm, Penny, Christeson, Gail, Cita, Maria Bianca, Class, Cornelia, Coble, Paula, Conte, Maureen, Cooke, Penelope, Cormier, Marie-Helene, Crane, Kathleen, Daly, Kendra L., Darling, Kate, de Angelis, Marie, De La Rocha, Christina, Demopoulos, Amanda W.J., Dierssen, Heidi, Druffel, Ellen R.M., Edmonds, Henrietta N., Edwards, Margo, Erba, Elisabetta, Ercilla, Gemma, Escutia, Carlota, Estrada, Marta, Falkner, Kelly Kenison, Fine, Rana A., Frank, Tracy D., Gardner, Joan M., Gargett, Ann, Garzoli, Silvia L., Gibson, Deidre M., Gillis, Kathryn, Gilbert, Patricia M., Goffredi, Shana K., Greengrove, Cheryl, Hall, Julie, Muller, Pamela Hallock, Hamme, Roberta C., Harada, Naomi, Harwood, Lois, Haymon, Rachel M., Heywood, Karen J., Hickey, Barbara M., Hill, Tessa M., Hooft, Emilie, Hummon, Julia M., Humphris, Susan E., Hutchinson, Deborah R., Ingalls, Anitra E., Isern, Alexandra R., Johns, Elizabeth, Joseph, Leah H., Joye, Samantha (Mandy), Kappel, Ellen S., Karp-Boss, Lee, Karsten, Jill, Kastner, Miriam, Kelley, Deborah S., Kim, Stacy, Klein, Emily M., Kominz, Michelle, Lange, Carina B., Lavín, Alicia M., Lavoie, Dawn, Leinen, Margaret S., Levin, Lisa A., Liepert, Beate, Lightsom, Frances, Lozier, M. Susan, Lynch-Stieglitz, Jean, Manley, Patricia Lee, Marcus, Nancy, Martin, Ellen E., Martini, Marinna, Matrai, Patricia A., McAndrew, Patricia, McClean, Julie, McGregor, Bonnie A., McHugh, Cecilia, McLaughlin, Fiona, McNutt, Marcia, McPhee-Shaw, Erika E., Mills, Rachel A., Moran, Kathryn, Mulholland, Margaret R., Muller-Parker, Gisèle, Mullineaux, Lauren, Neil, Helen, Noble, Marlene, O'Connell, Suzanne, Oppo, Delia, Orellana, Mónica V., Özkan-Haller, Tuba, Pascual, Mercedes, Passow, Uta, Paytan, Adina, Pilskaln, Cindy, Pyrtle, Ashanti J., Raffi, Isabella, Ravelo, Christina, Raymo, Maureen, Reguera, Beatriz, Reimers, Clare E., Reysenbach, Anna-Louise, Richardson, Mary Jo, Rickaby, Rosalind E.M., Rii, Shimi, Malanotte-Rizzoli, Paola, Robertson, Robin, Robinson, Rebecca, Rosenfeld, Leslie, Ross, Robin M., Ruppel, Carolyn, Russell, Ann D., Sabatés, Ana, Schwager, Katherine B., Scranton, Mary, Sherr, Evelyn B., Silver, Mary, Sloyan, Bernadette M., Smith, Deborah K., Sosik, Heidi M., Spitz, Yvette H., Stakes, Debra S., Stathoplos, Linda, Steinberg, Deborah K., Szmant, Alina M., Tachikawa, Kazuyo, Talaue-McManus, Liana, Talley, Lynne D., Tauxe, Lisa, Tester, Patricia A., Thomas, Debbie, Thomas, Ellen, Tolstoy, Maya, Torres, Marta E., Tréhu, Anne, Van Dover, Cindy Lee, Vlahos, Penny, Von Damm, Karen L., Wade, Bridget, Ward, Bess B., Wheeler, Patricia A., Whelan, Jean, White, Lisa D., Whitman, Jill M., Winckler, Gisela, Wishner, Karen F., Wright, Dawn, Wright, Elizabeth, Yalçin-Özdilek, Şükran, Yen, Jeannette, Yuan, Xiaojun, Zingone, Adriana, and Ziveri, Patrizia

Published
2005

21. Gas hydrates in sustainable chemistry

Author

Hassanpouryouzband, Aliakbar, primary, Joonaki, Edris, additional, Vasheghani Farahani, Mehrdad, additional, Takeya, Satoshi, additional, Ruppel, Carolyn, additional, Yang, Jinhai, additional, English, Niall J., additional, Schicks, Judith M., additional, Edlmann, Katriona, additional, Mehrabian, Hadi, additional, Aman, Zachary M., additional, and Tohidi, Bahman, additional

Published
2020
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23. Preface

Author

Hames, Willis E., primary, McHone, J. Gregory, additional, Renne, Paul R., additional, and Ruppel, Carolyn, additional

Published
2003
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26. Anomalously cold temperatures observed at the base of the gas hydrate stability zone on the U.S. Atlantic passive margin

Author

Ruppel, Carolyn

Subjects
Marine sediments -- Environmental aspects, Clathrate compounds -- Environmental aspects, Continental margins -- Natural history, Earth sciences
Abstract

In situ measurements to depths of [approximately]415 m below sea floor in methane hydrate-bearing sediments on the U.S. Atlantic passive margin indicate that temperatures at the bottom simulating reflector (BSR) are anomalously low by 0.5-2.9 [degrees] C if the BSR marks the base of gas hydrate stability (BGHS). Several hypotheses may explain the occurrence of the BSR at inappropriate pressure-temperature (P-T) conditions. (1) If the BSR does not mark the BGHS, then P-T conditions need not be sufficient to dissociate gas hydrate at this depth. (2) The BSR may lie at nonequilibrium P-T conditions due to incomplete readjustment in response to upper Pleistocene-Holocene climate change. However, the occurrence of the Blake Ridge BSR at an overly shallow depth cannot be easily explained by realistic combinations of pressure-driven deepening (sea-level rise) and temperature-driven shoaling (bottom water temperature changes). (3) The properties of sediments or pore fluids may inhibit the stability of gas hydrate. In particular, capillary forces arising in the fine-grained, montmorillonite-rich sediments of the Blake Ridge may lead to shoaling of the BSR in this setting.

Published
1997

27. The interaction of climate change and methane hydrates: Climate-Hydrates Interactions

Author

Ruppel, Carolyn D. and Kessler, John D.

Abstract

Gas hydrate, a frozen, naturally-occurring, and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. Gas hydrate is widespread in the sediments of marine continental margins and permafrost areas, locations where ocean and atmospheric warming may perturb the hydrate stability field and lead to release of the sequestered methane into the overlying sediments and soils. Methane and methane-derived carbon that escape from sediments and soils and reach the atmosphere could exacerbate greenhouse warming. The synergy between warming climate and gas hydrate dissociation feeds a popular perception that global warming could drive catastrophic methane releases from the contemporary gas hydrate reservoir. Appropriate evaluation of the two sides of the climate-methane hydrate synergy requires assessing direct and indirect observational data related to gas hydrate dissociation phenomena and numerical models that track the interaction of gas hydrates/methane with the ocean and/or atmosphere. Methane hydrate is likely undergoing dissociation now on global upper continental slopes and on continental shelves that ring the Arctic Ocean. Many factors—the depth of the gas hydrates in sediments, strong sediment and water column sinks, and the inability of bubbles emitted at the seafloor to deliver methane to the sea-air interface in most cases—mitigate the impact of gas hydrate dissociation on atmospheric greenhouse gas concentrations though. There is no conclusive proof that hydrate-derived methane is reaching the atmosphere now, but more observational data and improved numerical models will better characterize the climate-hydrate synergy in the future.

Published
2017

36. Exploration of the Canyon-Incised Continental Margin of the Northeastern United States Reveals Dynamic Habitats and Diverse Communities

Author

Quattrini, Andrea M., primary, Nizinski, Martha S., additional, Chaytor, Jason D., additional, Demopoulos, Amanda W. J., additional, Roark, E. Brendan, additional, France, Scott C., additional, Moore, Jon A., additional, Heyl, Taylor, additional, Auster, Peter J., additional, Kinlan, Brian, additional, Ruppel, Carolyn, additional, Elliott, Kelley P., additional, Kennedy, Brian R.C., additional, Lobecker, Elizabeth, additional, Skarke, Adam, additional, and Shank, Timothy M., additional

Published
2015
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38. SITE SELECTION FOR DOE/JIP GAS HYDRATE DRILLING IN THE NORTHERN GULF OF MEXICO

Author

Hutchinson, Deborah R., Shelander, Dianna, Dai, Jianchun, McConnel, Dan, Shedd, William, Frye, Matthew, Ruppel, Carolyn, Boswell, Ray, Jones, Emrys, Collett, Timothy S., Rose, Kelly, Dugan, Brandon, Wood, Warren, and Latham, Tom

Abstract

In the late spring of 2008, the Chevron-led Gulf of Mexico Gas Hydrate Joint Industry Project (JIP) expects to conduct an exploratory drilling and logging campaign to better understand gas hydrate-bearing sands in the deepwater Gulf of Mexico. The JIP Site Selection team selected three areas to test alternative geological models and geophysical interpretations supporting the existence of potential high gas hydrate saturations in reservoir-quality sands. The three sites are near existing drill holes which provide geological and geophysical constraints in Alaminos Canyon (AC) lease block 818, Green Canyon (GC) 955, and Walker Ridge (WR) 313. At the AC818 site, gas hydrate is interpreted to occur within the Oligocene Frio volcaniclastic sand at the crest of a fold that is shallow enough to be in the hydrate stability zone. Drilling at GC955 will sample a faulted, buried Pleistocene channel-levee system in an area characterized by seafloor fluid expulsion features, structural closure associated with uplifted salt, and abundant seismic evidence for upward migration of fluids and gas into the sand-rich parts of the sedimentary section. Drilling at WR313 targets ponded sheet sands and associated channel/levee deposits within a minibasin, making this a non-structural play. The potential for gas hydrate occurrence at WR313 is supported by shingled phase reversals consistent with the transition from gas-charged sand to overlying gas-hydrate saturated sand. Drilling locations have been selected at each site to 1) test geological methods and models used to infer the occurrence of gas hydrate in sand reservoirs in different settings in the northern Gulf of Mexico; 2) calibrate geophysical models used to detect gas hydrate sands, map reservoir thicknesses, and estimate the degree of gas hydrate saturation; and 3) delineate potential locations for subsequent JIP drilling and coring operations that will collect samples for comprehensive physical property, geochemical and other analyses

Published
2008
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39. Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane.

Author

Pohlman, John W., Greinert, Jens, Ruppel, Carolyn, Silyakova, Anna, Vielstädte, Lisa, Casso, Michael, Mienert, Jürgen, and Bünz, Stefan

Subjects
METHANE & the environment, PHYTOPLANKTON, PHOTOSYNTHESIS, GLOBAL warming, GREENHOUSE gases & the environment, OCEAN-atmosphere interaction, MARINE ecology
Abstract

Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (<100 m water depth), methane released from the seafloor may reach the atmosphere and potentially amplify global warming. On the other hand, biological uptake of carbon dioxide (CO2) has the potential to offset the positive warming potential of emitted methane, a process that has not received detailed consideration for these settings. Continuous sea-air gas flux data collected over a shallow ebullitive methane seep field on the Svalbard margin reveal atmospheric CO2 uptake rates (-33,300 ± 7,900 µmol m-2d-1) twice that of surrounding waters and ~1,900 times greater than the diffusive sea-air methane efflux (17.3 ± 4.8 µmol m-2d-1). The negative radiative forcing expected from this CO2 uptake is up to 231 times greater than the positive radiative forcing from the methane emissions. Surface water characteristics (e.g., high dissolved oxygen, high pH, and enrichment of 13C in CO2) indicate that upwelling of cold, nutrient-rich water from near the seafloor accompanies methane emissions and stimulates CO2 consumption by photosynthesizing phytoplankton. These findings challenge the widely held perception that areas characterized by shallow-water methane seeps and/or strongly elevated sea-air methane flux always increase the global atmospheric greenhouse gas burden. [ABSTRACT FROM AUTHOR]

Published
2017
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47. Scientific Objectives of the Gulf of Mexico Gas Hydrate JIP Leg II Drilling

Author

Jones, Emrys, additional, Latham, Tom, additional, McConnell, Daniel Russell, additional, Frye, Matt, additional, Hunt, Jesse, additional, Shedd, William, additional, Shelander, Dianna, additional, Boswell, Ray, additional, Rose, Kelly, additional, Ruppel, Carolyn, additional, Hutchinson, Deborah R., additional, Collett, Timothy Scott, additional, Dugan, Brandon, additional, and Wood, Warren, additional

Published
2008
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