Variability of the oxygen minimum zone associated with primary productivity and hydrographic conditions in the Eastern North Pacific during the last 1200 years

Sánchez, Alberto; Juárez, Miryam; Ortiz-Hernández, Ma. Concepción; Domínguez-Samalea, Yaima

doi:10.1016/j.dsr.2022.103810

Cited by 3 publications

(4 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, these factors do not appear to have been fundamental drivers of expanded OMZs during phosphatization events. Ocean primary productivity, by contrast, is likely to have been a major contributor to the expansion of OMZs in seamount regions, with high productivity driven by enhanced nutrient availability increasing biological oxygen consumption in the water column 12,40 . Barium in deepsea sediments is a potentially useful proxy for paleo-ocean productivity 41 , and its concentration in Fe-Mn crusts (by adsorption) is commonly positively correlated with the degree of primary productivity 42 .…”

Section: Drivers Of Phosphatization Eventsmentioning

confidence: 99%

“…Operating conditions comprised a 15 kV accelerating voltage, 20 nA probe current, and a 2 μm beam. The spectral lines, peak time, and off-peak background time used for the wavelength-dispersive spectroscopy (WDS) analyses were as follows: F, Na, Si, Al, P, Ca (Kα, 20, 10), Ti, Mn, Fe, Co (Kα,40,20). Analytical results were reduced using the ZAF correction routines.…”

Section: Electron Probe Micro-analyzer (Epma)mentioning

confidence: 99%

See 1 more Smart Citation

WITHDRAWN: Episodic intensification of marine phosphorus burial over the last 80 million years

Li,

Peng,

Poulton

et al. 2023

Preprint

View full text Add to dashboard Cite

Marine phosphatization events cause episodic carbonate fluorapatite (CFA) precipitation on seamounts, and are commonly linked to growth hiatuses in ferromanganese (Fe-Mn) crusts. However, the full record of these events and their paleoenvironmental implications remain poorly understood, in large part due to poor age constraints. Here, we apply U-Pb dating to CFA in Fe-Mn crusts from the Western Pacific seamounts, representing the Earth’s oldest oceanic crust. These data reveal six distinct phosphatization events, which are aligned with Sr isotope records in CFA and phosphorite from both the Western Pacific and the Atlantic. This newly established CFA chronology tightens the timespan of phosphatization events and refines the age framework of Fe-Mn crusts. We subsequently utilize a multiproxy approach to demonstrate that the phosphatization events occurred coeval with the expansion of oceanic oxygen minimum zones. The Western Pacific Fe-Mn crusts thus document major perturbations in global oceanic phosphorus cycling, which appear to have been driven by climate-induced increases in primary productivity.

show abstract

Section: Drivers Of Phosphatization Eventsmentioning

confidence: 99%

Section: Electron Probe Micro-analyzer (Epma)mentioning

confidence: 99%

WITHDRAWN: Episodic intensification of marine phosphorus burial over the last 80 million years

Li,

Peng,

Poulton

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…supporting our finding above (Wang et al, 2019;Sańchez et al, 2022). Wang et al (2019) also proposed that nutrient-rich, higher d 15 N subarctic water, which was caused by incomplete nitrate utilization in the subarctic region when the Aleutian low is strong, might have been transported into the SBB and was recorded by sediment d 15 N during the Little Ice Age period.…”

Section: The Effect Of Upwelling and Marine Productivity On The Varia...supporting

confidence: 86%

“…After the death of the phytoplankton, the organic matter with a high d 15 N signal via sinking particles is preserved in the marine sediment (Rayner et al, 2003;Wang et al, 2019). Under the circumstance of complete nitrate utilization (biological fractionation effects are negligible) and the absence of sedimentary diagenesis, such changes can be recorded in marine sedimentary d 15 N (d 15 N sed ) (Altabet et al, 1999;Emmer and Thunell, 2000;Thunell and Kepple, 2004;Ward, 2011;Horak et al, 2016;Davis et al, 2019;Margolskee et al, 2019;Wang et al, 2019;Sańchez et al, 2022). Hence, in regions where these conditions are met, d 15 N sed is accepted as a proxy for the integrated rates of denitrification and the volume of the ODZ: when the ODZ is expanded and the water column denitrification is intensified, the d 15 N sed increases (Emmer and Thunell, 2000;Tems et al, 2015;Horak et al, 2016;Davis et al, 2019;Wang et al, 2019;Sańchez et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Local and remote forcing on the interannual variations of the sedimentary δ15N in Santa Barbara Basin during the past 80 years

et al. 2022

Front. Mar. Sci.

View full text Add to dashboard Cite

Sedimentary nitrogen isotope (δ15Nsed) in Santa Barbara Basin (SBB) has been mostly interpreted as the record of the eastern tropical North Pacific (ETNP) intermediate water denitrification process. Nevertheless, debate remains regarding sources and control mechanisms of δ15Nsed signal in SBB. Multi-proxy analyses including δ15Nsed, total organic carbon (TOC), total nitrogen (TN), C/N ratio, and marine biomarkers were performed on a 46-cm sediment core (SBB-190629) collected from SBB in 2019. The core was dated with varve counting and 210Pb dating method, showing a depositional history of 1938–2019 CE with a sedimentation rate of 0.564 cm/year. The findings show that the δ15Nsed record (at ~0.25-year resolution) ranges from 6.24‰ to 7.43‰, which was affected by both local and remote forcing. The long-term variations of the SBB δ15Nsed signature show a general decreasing trend from 1940 to the late 1980s, low values during 1980~2000, and an increase afterward, which is thought to reflect changes in ETNP denitrification induced by the strength of tropical trade winds. Our results also reveal a series of abrupt annual to multiannual changes, superimposed on the long-term variation mentioned above. The SBB local δ15N signal (Δδ15NSBB) is accessed by using the deviation from the mean δ15N (Δδ15N) of SBB-190629 to subtract the Δδ15N of the ETNP. The Δδ15NSBB record compares well with redox-sensitive proxies (Re/Mo ratio and C29 stanol/stenol ratio) from the SBB bottom water and with the OCmarine content calculated based on the C/N ratio mixing model, indicating that the Δδ15NSBB is mainly controlled by bottom water denitrification, which was induced by the change of upwelling intensity and marine productivity. Since various climatic factors (e.g., El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and North Pacific Gyre Oscillation (NPGO)) have different impacts on the upwelling intensity (hence the marine productivity and denitrification) in SBB on different timescales, the influence of combined climatic factors on SBB denitrification is time dependent.

show abstract

Deoxygenation of the Eastern Tropical North Pacific over the last 1200 years

Domínguez-Samalea,

Rey-Villiers,

Sánchez

2024

Quaternary International

View full text Add to dashboard Cite

Variability of the oxygen minimum zone associated with primary productivity and hydrographic conditions in the Eastern North Pacific during the last 1200 years

Cited by 3 publications

References 54 publications

WITHDRAWN: Episodic intensification of marine phosphorus burial over the last 80 million years

WITHDRAWN: Episodic intensification of marine phosphorus burial over the last 80 million years

Local and remote forcing on the interannual variations of the sedimentary δ15N in Santa Barbara Basin during the past 80 years

Deoxygenation of the Eastern Tropical North Pacific over the last 1200 years

Contact Info

Product

Resources

About