Recording Fidelity of Relative Paleointensity Characteristics in the North Pacific Ocean

Gai, Congcong; Liu, Yanguang; Shi, Xuefa; Sun, Chenguang; Jiang, Xiaodong; Liu, Jianxing; Zhong, Yi; Liu, Qingsong

doi:10.1029/2021jb022068

Cited by 5 publications

(2 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This implies that there is no remarkable difference in DRM fixing depth between the magnetizations carried by the magnetofossil and detrital components. This supports the inference of some previous works that tried to separate remanent magnetization carried by the two components (Gai et al., 2021; Ouyang et al., 2014).…”

Section: Discussionsupporting

confidence: 91%

“…It is considered that different RPI recording efficiency between these two components may be responsible for the climatic contamination, which is likely originated from their different acquisition efficiencies of natural remanent magnetization (NRM) and the normalizers usually used for RPI estimations, namely the anhysteretic remanent magnetization (ARM) and the isothermal remanent magnetization (IRM). Some previous studies using Pacific marine sediments proposed that RPI recording efficiency of the magnetofossil component is lower than that of the detrital component, and that increasing proportion of the magnetofossil component causes underestimation of RPI (Gai et al., 2021; Inoue et al., 2021; Li et al., 2022). This explains frequently reported anti‐correlation between RPI and the ratio of ARM susceptibility to saturation IRM ( k ARM /SIRM) (Hofmann & Fabian, 2009; Inoue et al., 2021; Li et al., 2022; Sakuramoto et al., 2017; Yamazaki et al., 2013), as k ARM /SIRM is a proxy for the proportion of the magnetofossil to detrital components (Egli, 2004; Yamazaki, 2008; Zhang et al., 2022) as well as magnetic grain size (Banerjee et al., 1981; King et al., 1982).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Difference in Relative Paleointensity Recording Efficiency of Magnetic Mineral Constituents in a Sediment Core Off Chile

Yamazaki

Shimono

et al. 2023

JGR Solid Earth

View full text Add to dashboard Cite

Progress of relative paleointensity (RPI) estimations using marine sediments has greatly contributed to better understanding of the behavior of the past geomagnetic field. To enhance further the reliability of RPI estimations, we must overcome the problem that climatically induced variations of magnetic‐mineral assemblages in sediments may influence RPI records. Two major constituents of magnetic‐mineral assemblages in marine sediments are magnetofossils and detrital magnetic minerals, and the latter consists of silicate‐hosted magnetic inclusions and unprotected magnetic minerals. It is necessary to understand different RPI recording efficiencies among those constituents to tackle the problem, but previous evaluations were inconclusive. We studied this issue using a sediment core taken from the southeast Pacific Ocean. Rock‐magnetic investigations revealed that the magnetic mineral assemblage of this core during the last ∼900 ka is a mixture of low‐coercivity magnetofossils and middle‐coercivity detrital unprotected partially oxidized magnetite. Natural remanent magnetization (NRM) vs. isothermal remanent magnetization (IRM) demagnetization diagram showed strong convex curvature, and RPI signals carried by the two components could be separated by calculating RPI from the gradients of 20–40 and 70–160 mT segments. We confirmed that RPI recording efficiency of magnetofossils is lower than that of detrital unprotected magnetites/maghemites. Because of the marginal overlap between the coercivity ranges of the two components, changes in their relative abundance do not influence RPI estimations. This condition is ideal for RPI estimations, and the resulted RPI curve closely coincides with that of the PISO‐1500 stack despite changes in the relative abundance of the two components.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Difference in Relative Paleointensity Recording Efficiency of Magnetic Mineral Constituents in a Sediment Core Off Chile

Yamazaki

Shimono

et al. 2023

JGR Solid Earth

View full text Add to dashboard Cite

show abstract

Paleoclimate evolution of the North Pacific Ocean during the late Quaternary: Progress and challenges

Zhong¹,

Lu²,

Wilson³

et al. 2023

Geosystems and Geoenvironment

View full text Add to dashboard Cite

Heterogenous westerly shifts linked to Atlantic meridional overturning circulation slowdowns

Gai,

Wu,

Roberts

et al. 2023

Commun Earth Environ

View full text Add to dashboard Cite

The mid-latitude westerly winds are a major component of the global atmospheric circulation and a dominant factor in mid-latitude climate change. Understanding their behaviour and the controls on their variations under different climate background states is essential for assessing climate system feedback. Here we present a midlatitude North Pacific Ocean aeolian dust record from core NP02 through the last glacial cycle, during which extreme and abrupt climatic oscillations occurred. We find low dust contents during Heinrich stadials 2, 4, 5, and 5a that we attribute using proxy-model comparison to westerly transportation path changes associated with Atlantic meridional overturning circulation (AMOC) reductions, which caused North Atlantic cooling and modified the westerly wave train pattern, particularly over the Tibetan Plateau. The finding that AMOC variations had significant impacts on the westerlies half-way around the world, through ocean-atmosphere interactions, improves understanding of large-scale westerly sensitivity to different climate states.

show abstract

Recording Fidelity of Relative Paleointensity Characteristics in the North Pacific Ocean

Abstract: As the largest ocean in the world, the Pacific Ocean preserves abundant information about geomagnetic field and paleoenvironmental evolutions (e.g.

Cited by 5 publications

References 104 publications

Difference in Relative Paleointensity Recording Efficiency of Magnetic Mineral Constituents in a Sediment Core Off Chile

Difference in Relative Paleointensity Recording Efficiency of Magnetic Mineral Constituents in a Sediment Core Off Chile

Paleoclimate evolution of the North Pacific Ocean during the late Quaternary: Progress and challenges

Heterogenous westerly shifts linked to Atlantic meridional overturning circulation slowdowns

Contact Info

Product

Resources

About