Evidence for changes in subsurface circulation in the late Eocene equatorial Pacific from radiolarian‐bound nitrogen isotope values
dc.contributor.author | Robinson, Rebecca S. | en_US |
dc.contributor.author | Moore, Theodore C. | en_US |
dc.contributor.author | Erhardt, Andrea M. | en_US |
dc.contributor.author | Scher, Howie D. | en_US |
dc.date.accessioned | 2015-09-01T19:30:59Z | |
dc.date.available | 2016-08-08T16:18:39Z | en |
dc.date.issued | 2015-07 | en_US |
dc.identifier.citation | Robinson, Rebecca S.; Moore, Theodore C.; Erhardt, Andrea M.; Scher, Howie D. (2015). "Evidence for changes in subsurface circulation in the late Eocene equatorial Pacific from radiolarian‐bound nitrogen isotope values." Paleoceanography 30(7): 912-922. | en_US |
dc.identifier.issn | 0883-8305 | en_US |
dc.identifier.issn | 1944-9186 | en_US |
dc.identifier.uri | https://hdl.handle.net/2027.42/113171 | |
dc.description.abstract | Microfossil‐bound organic matter represents an important archive of surface ocean environmental information. Sedimentary nitrogen (N) isotope reconstructions of surface nitrate consumption and nitrogen source changes are made using fossil diatom (autotrophs) and planktic foraminiferal (heterotrophs)‐bound organic matter with success. However, because diatoms and planktic foraminifera are poorly preserved and sedimentary organic matter content is near zero during the late Eocene, our ability to examine nutrient dynamics across this important climate transition is limited. Here we present new data exploring the use of N isotope records from radiolarian tests. A comparison of surface ocean nitrate and core top bulk and radiolarian N isotope values (as δ15N) from the equatorial Pacific indicates that radiolarian‐N records δ15N variability with fidelity but that a significant offset exists between bulk sedimentary and diatom δ15N values and those measured from radiolarians (~7.1 ± 1.1‰). A downcore profile of radiolarian δ15N values is compared to siliceous microfossil assemblage changes across the Eocene‐Oligocene boundary. Average of radiolarian‐bound δ15N values is 0.5 ± 2.0‰, which, when corrected using the offset derived from the modern surface samples, suggests that the mean nitrogen isotopic composition of the early Cenozoic eastern Pacific was not significantly different from today. The overall trend, of decreasing δ15N values with decreasing export productivity, is consistent with either a regional decline in pelagic denitrification or a large‐scale change in nutrient sources to the eastern equatorial Pacific (EEP), both linked to the cooling climate and changing intermediate water circulation. Decreasing/low δ15N values cooccur with high radiolarian species turnover at ~35.5 and 34 Ma, suggestive of a significant ecological change in the EEP, consistent with cooling and water mass distribution changes. The preliminary results suggest that radiolarian‐bound organic nitrogen represents another promising archive and underscores the fact that the different microfossil fractions must be separated to ensure robust results.Key PointsRadiolarian‐bound N isotopes are a good archive of surface nitrogenRadiolarian‐bound N isotope values decrease across the Eocene‐Oligocene boundaryClimate‐related ecological changes are likely responsible for the observed shift | en_US |
dc.publisher | Integr. Ocean Drill. Program Manage. Int., Inc. | en_US |
dc.publisher | Wiley Periodicals, Inc. | en_US |
dc.subject.other | nitrogen isotopes | en_US |
dc.subject.other | Eocene‐Oligocene Transition | en_US |
dc.subject.other | radiolarians | en_US |
dc.title | Evidence for changes in subsurface circulation in the late Eocene equatorial Pacific from radiolarian‐bound nitrogen isotope values | en_US |
dc.type | Article | en_US |
dc.rights.robots | IndexNoFollow | en_US |
dc.subject.hlbsecondlevel | Atmospheric and Oceanic Sciences | en_US |
dc.subject.hlbtoplevel | Science | en_US |
dc.description.peerreviewed | Peer Reviewed | en_US |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/113171/1/palo20227.pdf | |
dc.identifier.doi | 10.1002/2015PA002777 | en_US |
dc.identifier.source | Paleoceanography | en_US |
dc.identifier.citedreference | Robinson, R. S., and D. Sigman ( 2008 ), Nitrogen isotopic evidence for a poleward decrease in surface nitrate within the Ice Age Antarctic, Quat. Sci. Rev., 27, 1076 – 1090. | en_US |
dc.identifier.citedreference | Ren, H., D. Sigman, A. N. Meckler, B. Plessen, R. S. Robinson, Y. Rosenthal, and G. H. Haug ( 2009 ), Foraminiferal isotope evidence of reduced nitrogen fixation in the Ice Age Atlantic Ocean, Science, 323, 244 – 248. | en_US |
dc.identifier.citedreference | Ren, H., B. G. Brunelle, D. M. Sigman, and R. S. Robinson ( 2013 ), Diagenetic aluminum uptake into diatom frustule and preservation of diatom‐bound organic nitrogen, Mar. Chem., 155, 92 – 101. | en_US |
dc.identifier.citedreference | Robinson, R. S., B. G. Brunelle, and D. M. Sigman ( 2004 ), Revisiting nutrient utilization in the glacial Antarctic: Evidence from a new diatom‐bound N isotope method, Paleoceanography, 19, PA3001, doi: 10.1029/2003PA000996. | en_US |
dc.identifier.citedreference | Robinson, R. S., D. M. Sigman, P. J. DiFiore, M. M. Rohde, T. A. Mashiotta, and D. W. Lea ( 2005 ), Diatom‐bound 15 N/ 14 N: New support for enhanced nutrient consumption in the Ice Age Subantarctic, Paleoceanography, 20, PA3003, do: 10.1029/2004PA2004001114. | en_US |
dc.identifier.citedreference | Robinson, R. S., P. Martinez, L. D. Pena, and I. Cacho ( 2009 ), Nitrogen isotopic evidence for deglacial changes in nutrient supply in the eastern equatorial Pacific, Paleoceanography, 24, PA4213, doi: 10.1029/2008PA001702. | en_US |
dc.identifier.citedreference | Robinson, R. S., et al. ( 2012 ), A review of nitrogen isotopic alteration in marine sediments, Paleoceanography, 27, PA4203, doi: 10.1029/2012PA002321. | en_US |
dc.identifier.citedreference | Robinson, R. S., J. Etourneau, P. M. Martinez, and R. Schneider ( 2014 ), Expansion of water column denitrification during early Pleistocene cooling, Earth Planet. Sci. Lett., 389, 52 – 61. | en_US |
dc.identifier.citedreference | Salamy, K. A., and J. C. Zachos ( 1999 ), Latest Eocene‐Early Oligocene climate change and Southern Ocean fertility: Inferences from sediment accumulation and stable isotope data, Palaeogeogr. Palaeoclimatol. Palaeoecol., 145, 61 – 77. | en_US |
dc.identifier.citedreference | Schlitzer, R. ( 2013 ), Ocean Data View edited. [Available at http://odv.awi.de.] | en_US |
dc.identifier.citedreference | Shipboard Scientific Party ( 2009 ), Initial Reports of Integrated Ocean Drilling Program Expeditions 320/321, edited by H. Palike et al., Integr. Ocean Drill. Program, College Station, Tex. | en_US |
dc.identifier.citedreference | Sigman, D. M., M. A. Altabet, R. Francois, D. C. McCorkle, and J.‐F. Gaillard ( 1999 ), The isotopic composition of diatom‐bound nitrogen in Southern Ocean sediments, Paleoceanography, 14 ( 2 ), 118 – 134, doi: 10.1029/1998PA900018. | en_US |
dc.identifier.citedreference | Sigman, D. M., K. L. Casciotti, M. Andreani, C. Barford, M. Galanter, and J. K. Böhlke ( 2001 ), A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater, Anal. Chem., 73, 4145 – 4153. | en_US |
dc.identifier.citedreference | Sigman, D. M., R. Robinson, A. N. Knapp, A. van Geen, D. C. McCorkle, J. A. Brandes, and R. C. Thunell ( 2003 ), Distinguishing between water column and sedimentary denitrification in the Santa Barbara Basin using the stable isotopes of nitrate, Geochem. Geophys. Geosyst., 4 ( 5 ), 1040, doi: 10.1029/2002GC000384. | en_US |
dc.identifier.citedreference | Straub, M., D. M. Sigman, H. Ren, A. Martinez‐Garcia, A. N. Meckler, M. P. Hain, and G. H. Haug ( 2013 ), Changes in North Atlantic nitrogen fixation controlled by ocean circulation, Nature, 501, 200 – 203, doi: 10.1038/nature12397. | en_US |
dc.identifier.citedreference | Studer, A., K. K. Ellis, S. Oleynik, D. M. Sigman, and G. H. Haug ( 2013 ), Size‐specific opal‐bound nitrogen isotopic measurement in North Pacific sediments, Geochim. Cosmochim. Acta, 120, 179 – 194. | en_US |
dc.identifier.citedreference | Swift, D. M., and A. P. Wheeler ( 1992 ), Evidence of an organic matrix from diatom biosilica, J. Phycology, 28, 202 – 209. | en_US |
dc.identifier.citedreference | Thomas, D. J. ( 2004 ), Evidence for deep‐water production in the North Pacific Ocean during the early Cenozoic warm interval, Nature, 430, 65 – 68. | en_US |
dc.identifier.citedreference | Toggweiler, J. R., and S. Carson ( 1995 ), What are the Upwelling Systems Contributing to the Ocean's Carbon and Nutrient Budgets?, John Wiley, New York. | en_US |
dc.identifier.citedreference | Via, R. K., and D. J. Thomas ( 2006 ), Evolution of Atlantic thermohaline circulation: Early Oligocene onset of deep‐water production in the North Atlantic, Geol. Soc. Am., 34 ( 6 ), 441 – 444. | en_US |
dc.identifier.citedreference | Westerhold, T., U. Rohl, H. Palike, R. Wilkens, P. A. Wilson, and G. Acton ( 2014 ), Orbitally tuned timescale and astronomical forcing in the middle Eocene to early Oligocene, Clim Past, 10, 955 – 973. | en_US |
dc.identifier.citedreference | Algeo, T. J., P. A. Meyers, R. S. Robinson, H. Rowe, and G. Q. Jiang ( 2014 ), Icehouse–greenhouse variations in marine denitrification, Biogeosciences, 11, 1. | en_US |
dc.identifier.citedreference | Altabet, M. ( 2001 ), Nitrogen isotopic evidence for micronutrient control of fractional NO 3 − utilization in the equatorial Pacific, Limnol. Oceanogr., 46, 368 – 380. | en_US |
dc.identifier.citedreference | Altabet, M. A., and R. Francois ( 1994 ), Sedimentary nitrogen isotopic ratio as a recorder for surface nitrate utilization, Global Biogeochem. Cycles, 8 ( 1 ), 103 – 116, doi: 10.1029/93GB03396. | en_US |
dc.identifier.citedreference | Baldauf, J. G. ( 2013 ), Data Report: Diatoms From Sites U1334 and U1338, Expedition 320/321, Integr. Ocean Drill. Program Manage. Int., Inc., Tokyo. | en_US |
dc.identifier.citedreference | Braman, R. S., and S. A. Hendrix ( 1989 ), Nanogram nitrite and nitrate determination in environmental and biological‐materials by Vanadium(III) reduction with chemi‐luminescence detection, Anal. Chem., 61 ( 24 ), 2715 – 2718. | en_US |
dc.identifier.citedreference | Scher, H. D., and E. E. Martin ( 2006 ), Timing and climatic consequences of the opening of the Drake Passage, Science, 312, 428 – 430. | en_US |
dc.identifier.citedreference | Brandes, J. A., A. H. Devol, T. Yoshinare, D. A. Jayakumar, and S. W. A. Naqvi ( 1998 ), Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: A tracer for mixing and nitrogen cycles, Limnol. Oceanogr., 43, 1680 – 1689. | en_US |
dc.identifier.citedreference | Christensen, J. P., D. W. Murray, A. Devol, and L. Codispoti ( 1987 ), Denitrification in continental shelf sediments has major impact on the oceanic nitrogen budget, Global Biogeochem. Cycles, 1 ( 2 ), 97 – 116, doi: 10.1029/GB001i002p00097. | en_US |
dc.identifier.citedreference | Coxall, H. K., P. A. Wilson, H. Palike, C. H. Lear, and J. Backman ( 2005 ), Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean, Nature, 433, 53 – 57. | en_US |
dc.identifier.citedreference | Cramer, B. S., J. R. Toggweiler, J. D. Wright, M. E. Katz, and K. G. MIller ( 2009 ), Ocean overturning since the Late Cretaceous: Inferences from a new benthic foraminiferal isotope compilation, Paleoceanography, 24, PA4216, doi: 10.1029/2008PA001683. | en_US |
dc.identifier.citedreference | DeConto, R., and R. T. Pollard ( 2003 ), Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO 2, Nature, 421, 245 – 247. | en_US |
dc.identifier.citedreference | DeConto, R., D. Pollard, P. A. Wilson, H. Palike, C. H. Lear, and M. Pagani ( 2008 ), Thresholds for Cenozoic bipolar glaciation, Nature, 455, doi: 10.1038/nature07337. | en_US |
dc.identifier.citedreference | DeNiro, M. J., and S. Epstein ( 1981 ), Influence of diet on the distribution of nitrogen isotopes in animals, Geochim. Cosmochim. Acta, 45, 341 – 351. | en_US |
dc.identifier.citedreference | Deutsch, C., D. M. Sigman, R. C. Thunell, A. N. Meckler, and G. H. Haug ( 2004 ), Isotopic constraints on glacial/interglacial changes in the oceanic nitrogen budget, Global Biogeochem. Cycles, 18, GB4012, doi: 10.1029/2003GB002189. | en_US |
dc.identifier.citedreference | Diester‐Haass, L. ( 1995 ), Middle Ecoene to early Oligocene paleoceanography of the Antarctic Ocean (Maud Rise, ODP Leg 113, Site 689): Change from a low to a high productivity ocean, Palaeogeogr. Palaeoclimatol. Palaeoecol., 113, 311 – 334. | en_US |
dc.identifier.citedreference | Dubois, N., M. Kienast, S. Kienast, C. Normandeau, S. E. Calvert, T. Herbert, and A. Mix ( 2011 ), Millenial‐scale variations in hydrography and biogeochemistry in the Eastern Equatorial Pacific over the last 100 ky, Quat. Sci. Rev., 30, 210 – 223. | en_US |
dc.identifier.citedreference | Egan, K. E., R. E. M. Rickaby, K. R. Hendry, and A. N. Halliday ( 2013 ), Opening the gateways for diatoms primes Earth for Antarctic glaciation, Earth Planet. Sci. Lett., 375, 34 – 43. | en_US |
dc.identifier.citedreference | Erhardt, A. M., H. Pälike, and A. Payton ( 2013 ), High‐resolution record of export production in the eastern equatorial Pacific across the Eocene‐Oligocene transition and relationships to global climatic records, Paleoceanography, 28, 130 – 142, doi: 10.1029/2012PA002347. | en_US |
dc.identifier.citedreference | Etourneau, J., R. S. Robinson, P. M. Martinez, and R. Schneider ( 2013 ), Large changes in upwelling intensity, biological production and nutrient utilization in the Eastern Equatorial Pacific over the last 3.2 Ma, Biogeosciences, 10, 5663 – 5670. | en_US |
dc.identifier.citedreference | Farrell, J. W., T. F. Pedersen, S. E. Calvert, and B. Nielsen ( 1995 ), Glacial‐interglacial changes in nutrient utilization in the equatorial Pacific Ocean, Nature, 377, 514,516. | en_US |
dc.identifier.citedreference | Francois, R., M. A. Altabet, E.‐F. Yu, D. M. Sigman, M. P. Bacon, M. Frank, G. Bohrmann, G. Bareille, and L. D. Labeyrie ( 1997 ), Contributions of Southern Ocean surface‐water stratification to low atmospheric CO 2 concentrations during the last glacial period, Nature, 389, 929 – 935. | en_US |
dc.identifier.citedreference | Funakawa, S., H. Nishi, T. C. Moore, and C. Nigrini ( 2006 ), Radiolarian faunal turnover and paleoceanographic change around Eocene/Oligocene boundary in the central equatorial Pacific, ODP Leg 199, Holes 1218A, 1219A, and 1220A, Palaeogeogr. Palaeoclimatol. Palaeoecol., 230, 183 – 203. | en_US |
dc.identifier.citedreference | Galbraith, E. D., D. M. Sigman, R. S. Robinson, and T. F. Pedersen ( 2008 ), Past changes in the marine nitrogen cycle, in Nitrogen in the Marine Environment, edited by D. G. Capone et al., pp. 1497 – 1535, Academic Press, San Diego, Calif. | en_US |
dc.identifier.citedreference | Garcia, H. E., R. A. Locarnini, T. P. Boyer, J. I. Antonov, M. M. Zweng, O. K. Baranova, and D. R. Johnson ( 2010 ), World Ocean Atlas 2009 Volume 4: Nutrients (Phosphate, Nitrate, Silicate), 26 pp., Ocean Climate Lab., Natl. Oceanogr. Data Center, Silver Spring, Md. | en_US |
dc.identifier.citedreference | Griffith, E., M. Calhoun, E. Thomas, K. B. Averyt, A. M. Erhardt, T. J. Bralower, M. Lyle, A. Olivarez Lyle, and A. Paytan ( 2010 ), Export productivity and carbonate accumulation in the Pacific Basin at the transition from a greenhouse to icehouse climate (late Eocene to early Oligocene), Paleoceanography, 25, PA3212, doi: 10.1029/2010PA001932. | en_US |
dc.identifier.citedreference | Horn, M., C. P. Beucher, R. S. Robinson, and M. Brzezinski ( 2011a ), Nitrogen and silicon dynamics during the last deglaciation, Earth Planet. Sci. Lett., 310, 334 – 339. | en_US |
dc.identifier.citedreference | Horn, M., R. S. Robinson, T. A. Rynearson, and D. Sigman ( 2011b ), Nitrogen isotopic relationship between diatom‐bound and bulk organic matter of cultured polar diatoms, Paleoceanography, 26, PA3208, doi: 10.1029/2010PA002080. | en_US |
dc.identifier.citedreference | Kalansky, J., R. S. Robinson, and B. N. Popp ( 2011 ), Insights into nitrogen cycling in the western Gulf of California from the nitrogen isotopic composition of diatom‐bound organic matter, Geochem. Geophys. Geosyst., 12, Q06015, doi: 10.1029/2010GC003437. | en_US |
dc.identifier.citedreference | Katz, M. E., B. S. Cramer, J. R. Toggweiler, G. Esmay, C. Liu, K. G. Miller, Y. Rosenthal, B. S. Wade, and J. D. Wright ( 2011 ), Impact of Antarctic Circumpolar Current development on Late Paleogene ocean structure, Science, 332, 1076 – 1078. | en_US |
dc.identifier.citedreference | King, K., Jr. ( 1977 ), Amino acid survey of recent calcareous and siliceous deep‐sea microfossils, Micropaleontology, 23 ( 2 ), 180 – 193. | en_US |
dc.identifier.citedreference | Kroger, N., R. Deutzmann, and M. Sumper ( 1999 ), Polycationic peptides from diatom biosilica that direct silica nanosphere formation, Science, 286 ( 5442 ), 1129 – 1132. | en_US |
dc.identifier.citedreference | Macko, S. A., and M. L. F. Estep ( 1984 ), Microbial alteration of stable nitrogen and carbon isotopic compositions of organic matter, Org. Geochem., 6, 787 – 790. | en_US |
dc.identifier.citedreference | Macko, S. A., M. L. Fogel, M. H. Engel, and P. E. Hare ( 1986 ), Kinetic fractionation of stable nitrogen isotopes during amino acid transamination, Geochim. Cosmochim. Acta, 50, 2143 – 2146. | en_US |
dc.identifier.citedreference | Martin, E. E., and H. D. Scher ( 2004 ), Preservation of seawater Sr and Nd isotopes in fossil fish teeth: Bad news and good news, Earth Planet. Sci. Lett., 220 ( 1–2 ), 25 – 39. | en_US |
dc.identifier.citedreference | Martinez‐Garcia, A., D. M. Sigman, H. Ren, R. F. Anderson, M. Straub, D. Hodell, S. L. Jaccard, T. I. Eglinton, and G. H. Haug ( 2014 ), Iron fertilization of the Subantarctic Ocean during the Last Ice Age, Science, 343, 1347 – 1350. | en_US |
dc.identifier.citedreference | Middelburg, J. J., K. Soetaert, P. M. J. Herman, and C. H. R. Heip ( 1996 ), Denitrification in marine sediments: A model study, Global Biogeochem. Cycles, 10 ( 4 ), 661 – 673, doi: 10.1029/96GB02562. | en_US |
dc.identifier.citedreference | Moore, T. C. ( 2013 ), Erosion and reworking of Pacific sediments near the Eocene‐Oligocene boundary, Paleoceanography, 28, 263 – 273, doi: 10.1002/palo.20027. | en_US |
dc.identifier.citedreference | Moore, T. C., B. S. Wade, T. Westerhold, A. M. Erhardt, H. K. Coxall, J. Baldauf, and M. Wagner ( 2014 ), Equatorial Pacific productivity changes near the Eocene‐Oligocene boundary, Paleoceanography, 29, 825 – 844, doi: 10.1002/2014PA002656. | en_US |
dc.identifier.citedreference | Moore, T. C., Jr., S. Kamikuri, A. M. Erhardt, J. Baldauf, H. K. Coxall, and T. Westerhold ( 2015 ), Radiolarian stratigraphy near the Eocene–Oligocene boundary, Mar. Micropaleontol., 116, 50 – 62. | en_US |
dc.identifier.citedreference | Morales, L. V., D. M. Sigman, M. G. Horn, and R. S. Robinson ( 2013 ), Cleaning methods for the isotopic determination of diatom bound nitrogen in non‐fossil diatom frustules, Limnol. Oceanogr. Methods, 11, 101 – 112. | en_US |
dc.identifier.citedreference | Morales, L. V., J. Granger, B. X. Chang, M. Prokopenko, B. Plessen, R. Gradinger, and D. M. Sigman ( 2014 ), Elevated 15N/14N in particulate organic matter, zooplankton, and diatom frustule‐bound nitrogen in the ice‐covered water column of the Bering Sea eastern shelf, Deep Sea Res., Part II, 109, 100 – 111. | en_US |
dc.identifier.citedreference | Olivarez Lyle, A., and M. Lyle ( 2006 ), Organic carbon and barium in Eocene sediments: Possible controls on nutrient recycling in the Eocene equatorial Pacific Ocean, in Proceedings of the Ocean Drilling Program, Scientific Results, edited by P. A. Wilson et al., Ocean Drill. Program, College Station, Tex. | en_US |
dc.identifier.citedreference | Pagani, M., J. C. Zachos, K. H. Freeman, B. Tipple, and S. Bohaty ( 2005 ), Marked decline in atmospheric carbon dioxide concentrations during the Paleogene, Science, 309, 600 – 603. | en_US |
dc.identifier.citedreference | Palike, H., et al. ( 2012 ), A Cenozoic record of the equatorial Pacific carbonate compensation depth, Nature, 488 ( 7413 ), 609 – 614. | en_US |
dc.identifier.citedreference | Pearson, P. N., G. L. Foster, and B. S. Wade ( 2009 ), Atmospheric carbon dioxide through the Eocene–Oligocene climate transition, Nature, 46, 1110 – 1113, doi: 10.1038/nature08447. | en_US |
dc.identifier.citedreference | Rafter, P. A., and C. Charles ( 2012 ), Pleistocene equatorial Pacific dynamics inferred from the zonal asymmetry in sedimentary nitrogen isotopes, Paleoceanography, 27, PA3102, doi: 10.1029/2012PA002367. | en_US |
dc.identifier.citedreference | Rafter, P. A., D. M. Sigman, C. D. Charles, J. Kaiser, and G. H. Haug ( 2012 ), Subsurface tropical Pacific nitrogen isotopic composition of nitrate: Biogeochemical signals and their transport, Global Biogeochem. Cycles, 26, GB1003, doi: 10.1029/2010GB003979. | en_US |
dc.owningcollname | Interdisciplinary and Peer-Reviewed |
Files in this item
Remediation of Harmful Language
The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.
Accessibility
If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.