High-resolution paleomagnetic secular variations and relative paleointensity since the Late Pleistocene in southern South America

Lisé-Pronovost, Agathe; St‐Onge, Guillaume; Gogorza, Claudia; Haberzettl, Torsten; Préda, Michel; Kliem, P.; Francus, Pierre; Zolitschka, Bernd

doi:10.1016/j.quascirev.2012.05.012

Cited by 42 publications

(33 citation statements)

References 93 publications

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“…Additional sediment records that were not used in the CALS10k.2 and HFM.OL1.A1 models have been employed in GGF100k. They mostly come from lakes covering the past 10 ka and beyond, for example, Lake Yogo (Hyodo et al, ); Beppu Bay (Ohno et al, ); Shikoku, Japan Sea (Ohno et al, ); Sun‐Moon Lake, Taiwan (Lee et al, ); Lake Tangra Yumco, Tibetan Plateau (Henkel et al, ); MD06‐3040, China Sea (Zheng et al, ); Mavora Lakes, New Zealand (Turner et al, ); LPA and PTA03, Laguna Potrok Aike, Argentina (Gogorza et al, ; Kliem et al, ; Lisé‐Pronovost et al, ); and Indonesian records from South Makassar Basin and Celebs Sea (Lund et al, ).…”

Section: Resultsmentioning

confidence: 99%

“…In Figure b predictions of the model with smoothing kernels are compared with sediment records from nearby locations to illustrate their effect on the model. The model captures not only some high‐frequency variations present in the raw ODP 1089 record but also variations from nearby locations, for instance, 21‐pc02 record (Channell et al, ; Stoner et al, ), and the very detailed LPA sediment record (Lisé‐Pronovost et al, ) with estimated T s s of 110 years has pronounced effects over its whole duration of 0–50 ka. In Figure c we show how a model that does not take account of the smoothing in the forward model in all three components has generally larger residuals than one that does.…”

Section: Modeling Methodsmentioning

confidence: 99%

“…(a) The three components of ODP 1089 are smoothed with T s s = 1,000 years, and the smoothed records are used to build a model with and without smoothing kernels. (b) Predictions at the ODP 1089 location are compared with intensity data from nearby locations (21‐pc02, South Atlantic, Stoner et al, , ; and LPA, Laguna Potrok Aike in Argentina, Lisé‐Pronovost et al, ) to check their influence on the model with implemented smoothing kernels. (c) Comparison of residuals of the two models to the smoothed ODP 1089 data (gray dots in subplot a) used to constrain the models; that is, predictions of the model with smoothing kernels are smoothed with T s s = 1,000 years, and individual epoch predictions are used for the model without smoothing kernels.…”

Section: Modeling Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Extending Global Continuous Geomagnetic Field Reconstructions on Timescales Beyond Human Civilization

Panovska

Constable

Korte

2018

Geochem Geophys Geosyst

141

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Study of the late Quaternary geomagnetic field contributes significantly to understanding the origin of millennial‐scale paleomagnetic secular variations, the structure of geomagnetic excursions, and the long‐term shielding by the geomagnetic field. A compilation of paleomagnetic sediment records and archeomagnetic and lava flow data covering the past 100 ka enables reconstruction of the global geomagnetic field on such long‐term scales. We use regularized inversion to build the first global, time‐dependent, geomagnetic field model spanning the past 100 ka, named GGF100k (Global Geomagnetic Field over the past 100 ka). Spatial parametrization of the model is in spherical harmonics and time variations with cubic splines. The model is heavily constrained by more than 100 continuous sediment records covering extended periods of time, which strongly prevail over the limited number of discrete snapshots provided by archeomagnetic and volcanic data. Following an assessment of temporal resolution in each sediment's magnetic record, we have introduced smoothing kernels into the forward modeling when assessing data misfit. This accommodates the smoothing inherent in the remanence acquisition in individual sediment paleomagnetic records, facilitating a closer fit to both high‐ and low‐resolution records in regions where some sediments have variable temporal resolutions. The model has similar spatial resolution but less temporal complexity than current Holocene geomagnetic field models. Using the new reconstruction, we discuss dipole moment variations, the time‐averaged field, and paleomagnetic secular variation activity. The new GGF100k model fills the gap in the geomagnetic power spectrum in the frequency range 100–1,000 Ma−1.

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Section: Resultsmentioning

confidence: 99%

Section: Modeling Methodsmentioning

confidence: 99%

Section: Modeling Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Extending Global Continuous Geomagnetic Field Reconstructions on Timescales Beyond Human Civilization

Panovska

Constable

Korte

2018

Geochem Geophys Geosyst

141

View full text Add to dashboard Cite

show abstract

“…E,F). The ODP site 1233 PSV record has been correlated to eight other PSV records throughout the Southern Hemisphere (Lisé‐Pronovost et al ., ) giving precedence to its use as a regional reference record. The fit to the LCB record is quite good, except for the anomalous inclination shallowing in the top 10–20 cm (Fig.…”

Section: Resultsmentioning

confidence: 99%

Geophysical and geochemical constraints on the age and paleoclimate implications of Holocene lacustrine cores from the Andes of central Chile

Tiner

Negrini

Antinao

et al. 2018

J Quaternary Science

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A Holocene paleoclimate record was constructed using two lacustrine cores from the high‐elevation Chilean Andes at ∼30°S latitude. Coarser and more poorly sorted grain‐size distributions and higher C/N ratios were interpreted as evidence for increased storm activity. Wet conditions prevailed from ∼10.8 to 9.5k cal a BP, then transitioned to dry conditions from ∼9.5 to 5.7k cal a BP interrupted by stormy conditions from ∼8.3 to 7.6k cal a BP. Wet conditions returned from ∼5.7k cal a BP to the present, interrupted by aridity from ∼4.1 to 2.2k cal a BP. This paleoclimate record is consistent with others from the region. The wet periods were probably caused by the influence of the Southern Westerlies, while dry conditions resulted from the influence of the Southeast Pacific Anticyclone. The increased storminess from ∼8.3 to 7.7k cal a BP may have been sourced from latitudinal shifts in the Intertropical Convergence Zone and subsequent weakening of the Westerlies, allowing the incursion of convective storms from east of the Andes. This sequence of events is consistent with synoptic conditions during modern easterly sourced storm activity. It is also consistent with modeling studies of the effect on the Southern Hemisphere of the rapid cooling of the North Atlantic Ocean during the 8.2‐ka event.

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“…A significant number of records are also available from the PANGAEA (Diepenbroek et al, 2002) and the Ocean Drilling Program (ODP) and International Ocean Discovery Program (IODP) databases (http://www-odp.tamu.edu/database/). In recent years, there have been a number of new corings (e.g., Collins et al, 2012;Channell et al, 2012aChannell et al, , 2012bLis e-Pronovost et al, 2013;Nilsson et al, 2011;Nowaczyk et al, 2012;Xiao et al, 2016;Yang et al, 2012) that significantly enhance global data coverage. These studies provide high-resolution paleointensity and directional records that will facilitate the construction of global, time-dependent models of the 0-100 ka geomagnetic field.…”

Section: Introductionmentioning

confidence: 99%

Global and Regional Assessments of Paleosecular Variation Activity Over the Past 100 ka

Panovska

Constable

Brown

2018

Geochem Geophys Geosyst

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We present a global compilation of paleomagnetic data spanning the past 100 ka. Sediment data comprise 61,687 declinations, 70,936 inclinations, and 69,596 relative paleointensities. Many sites are located in the northern Atlantic and western Pacific, with approximately twice as many data from the Northern Hemisphere as from the Southern Hemisphere. The 14,954 volcanic and archeomagnetic data are sparse, especially in the Southern Hemisphere. Directional and intensity information are aggregated under the paleosecular variation (PSV) index to assess occurrence of excursions over the past 100 ka. The Laschamp excursion (∼41 ka) is clearly defined across globally distributed sediment records with an average duration of 1,300 years. Regional stacks obtained using bootstrap resampling show a more pronounced Laschamp excursion in the Northern Hemisphere than in the Southern, and in the Atlantic Hemisphere compared with the Pacific. No anomalous indices occurred around the Mono Lake excursion or other periods in the bootstrap curves. This may result from low sedimentation rates, discrepancies in age scales, large age errors, and/or the lack of global character of any transitional events. These data and associated new uncertainty estimates for the sediment records provide a good foundation for global, time‐dependent, spherical harmonic field modeling for the past 100 ka.

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High-resolution paleomagnetic secular variations and relative paleointensity since the Late Pleistocene in southern South America

Cited by 42 publications

References 93 publications

Extending Global Continuous Geomagnetic Field Reconstructions on Timescales Beyond Human Civilization

Extending Global Continuous Geomagnetic Field Reconstructions on Timescales Beyond Human Civilization

Geophysical and geochemical constraints on the age and paleoclimate implications of Holocene lacustrine cores from the Andes of central Chile

Global and Regional Assessments of Paleosecular Variation Activity Over the Past 100 ka

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