Recording Fidelity of Relative Paleointensity Characteristics in the North Pacific Ocean

North Pacific Ocean sediments are important archives of geomagnetic field and paleoenvironmental evolutions, yet late Quaternary sedimentary sequences in the North Pacific Ocean are less explored because of generally low sedimentation rates and the challenge of dating sediments deposited below the calcite compensation depth. Core NP02 sediments from the North Pacific Ocean contain three visible tephra layers, which are identified as the To-Of, Spfa-1, and Kt-3 tephra, respectively. An age model for core NP02 is established based on tephra correlation and one radiocarbon date, which gives a mean sedimentation rate of similar to 11.6 cm/kyr. Magnetic analyses suggest the dominance of two remanence carriers; detrital vortex state and biogenic single domain magnetite. Variable depth offsets between the relative paleointensity (RPI) signals carried by the two remanence carriers adds a negligible age error (<0.5 kyr) to the core NP02 RPI record. Pronounced RPI amplitude variations are observed, and the Rockall and Laschamp excursions are identified in the core NP02 RPI record based on the age model. The fidelity of the core NP02 RPI record is further verified by comparison with other RPI stacks and records, and we demonstrate that the RPI variations can assist in chronology refinement.

Automated summary

Studies have shown that sediments from core NP02 in the North Pacific Ocean have an average sedimentation rate of around 11.6 cm/kyr, with detrital vortex state and biogenic single domain magnetite as dominant remanence carriers. The age model based on tephra correlation and radiocarbon dating confirms the reliability of the core NP02 relative paleointensity (RPI) record, with negligible age error added by depth offsets between remanence carriers. RPI variations in the core NP02 record, including the Rockall and Laschamp excursions, can help refine chronology and are consistent with other RPI stacks and records.