Crustal thickness and Moho character of the fast-spreading East Pacific Rise from 9°42′N to 9°57′N from poststack-migrated 3-D MCS data
Nedimovic, Mladen R.
Carbotte, Suzanne M.
Canales, J. Pablo
Mutter, John C.
MetadataShow full item record
KeywordEast Pacific Rise; Oceanic crust; Moho discontinuity; Multichannel seismic data; 3-D reflection imaging
We computed crustal thickness (5740 ± 270 m) and mapped Moho reflection character using 3-D seismic data covering 658 km2 of the fast-spreading East Pacific Rise (EPR) from 9°42′N to 9°57′N. Moho reflections are imaged within ∼87% of the study area. Average crustal thickness varies little between large sections of the study area suggesting regionally uniform crustal production in the last ∼180 Ka. However, individual crustal thickness measurements differ by as much as 1.75 km indicating that the mantle melt delivery has not been uniform. Third-order, but not fourth-order ridge discontinuities are associated with changes in the Moho reflection character and/or near-axis crustal thickness. This suggests that the third-order segmentation is governed by melt distribution processes within the uppermost mantle while the fourth-order ridge segmentation arises from midcrustal to upper-crustal processes. In this light, we assign fourth-order ridge discontinuity status to the debated ridge segment boundary at ∼9°45′N and third-order status at ∼9°51.5′N to the ridge segment boundary previously interpreted as a fourth-order discontinuity. Our seismic results also suggest that the mechanism of lower-crustal accretion varies along the investigated section of the EPR but that the volume of melt delivered to the crust is mostly uniform. More efficient mantle melt extraction is inferred within the southern half of our survey area with greater proportion of the lower crust accreted from the axial magma lens than that for the northern half. This south-to-north variation in the crustal accretion style may be caused by interaction between the melt sources for the ridge and the Lamont seamounts.
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 15 (2014): 634–657, doi:10.1002/2013GC005069.
Suggested CitationArticle: Aghaei, Omid, Nedimovic, Mladen R., Carton, Helene, Carbotte, Suzanne M., Canales, J. Pablo, Mutter, John C., "Crustal thickness and Moho character of the fast-spreading East Pacific Rise from 9°42′N to 9°57′N from poststack-migrated 3-D MCS data", Geochemistry, Geophysics, Geosystems 15 (2014): 634–657, DOI:10.1002/2013GC005069, https://hdl.handle.net/1912/6711
Showing items related by title, author, creator and subject.
Evidence from diatom-bound nitrogen isotopes for subarctic Pacific stratification during the last ice age and a link to North Pacific denitrification changes Brunelle, Brigitte G.; Sigman, Daniel M.; Cook, Mea S.; Keigwin, Lloyd D.; Haug, Gerald H.; Plessen, Birgit; Schettler, Georg; Jaccard, Samuel L. (American Geophysical Union, 2007-03-02)In a piston core from the central Bering Sea, diatom microfossil-bound N isotopes and the concentrations of opal, biogenic barium, calcium carbonate, and organic N are measured over the last glacial/interglacial cycle. ...
Amino acid compound specific isotope values for micronekton from R/V Kilo Moana KM1109, KM1123, KM1407, KM1418, and other cruises in the Central North Pacific, Station ALOHA, Tropical Pacific, 2007-2014 Popp, Brian N.; Benitez-Nelson, Claudia; Blum, Joel; Drazen, Jeffrey C.; Hannides, Cecelia; Seraphin, Kanesa (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2019-03-18)This dataset contains amino acid compound specific concentrations in micronekton collected during R/V Kilo Moana cruises around the ALOHA observatory (KM1407, KM1418, KM2011, and a few other undocumented cruises). For more ...
Amino acid compound specific isotope values for particles from R/V Kilo Moana KM1407 and KM1418 in the Central North Pacific, Station ALOHA, Tropical Pacific, Feb and Sept. 2014 Popp, Brian N.; Benitez-Nelson, Claudia; Blum, Joel; Drazen, Jeffrey C.; Hannides, Cecelia; Seraphin, Kanesa (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: firstname.lastname@example.org, 2019-03-18)This dataset contains amino acid compound specific nitrogen isotope ratios in particles collected during R/V Kilo Moana cruises around Station ALOHA (KM1407 and KM1418). For more information about the ALOHA observatory ...