Four‐Dimensional Paleomagnetic Dataset: Plio‐Pleistocene Paleodirection and Paleointensity Results From the Erebus Volcanic Province, Antarctica

Asefaw, Hanna; Tauxe, Lisa; Koppers, Anthony A. P.; Staudigel, Hubert

doi:10.1029/2020jb020834

Cited by 9 publications

(41 citation statements)

References 81 publications

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“…We note that Asefaw et al. (2021) combined some sites; in our analysis, however, we still use the original, uncombined sites. Furthermore, we do not use the age constraint of <5 Ma and k ‐cutoff.…”

Section: Datasets and Approachmentioning

confidence: 99%

“…As basis for our analysis, we use four paleomagnetic datasets derived from lavas from Mongolia (van Hinsbergen et al., 2008), Norway (Haldan et al., 2014), Turkey (van Hinsbergen et al., 2010), and Antarctica (Asefaw et al., 2021). We chose these datasets because they consist of a particularly large number of paleomagnetic sites (with n ≥ 6 samples per site) and cover a broad range of paleolatitudes and ages.…”

Section: Datasets and Approachmentioning

confidence: 99%

“…Finally, we use 107 sites with n = 6 from lavas of Plio‐Pleistocene age of the Erebus volcanic province in Antarctica at a latitude of ∼75°S (Asefaw et al., 2021; A21). We did not reinterpret this data set and use the published interpretations, but only use sites with n = 6.…”

Section: Datasets and Approachmentioning

confidence: 99%

“…Based on Monte Carlo simulations, a minimum number of five independently oriented samples was deemed necessary to estimate k reliably (Tauxe et al., 2003). Others suggest that three (Meert et al., 2020), four (Cromwell et al., 2018; Lippert et al., 2014), or six (Asefaw et al., 2021) samples are needed. Most paleomagnetic studies collected six to eight samples per lava site.…”

Section: Introductionmentioning

confidence: 99%

“…Each paleomagnetic direction represents a paleomagnetic component determined with the principal component analysis of Kirschvink (1980) that is interpreted by the expert as the characteristic remanent magnetization (ChRM). Each of these components comes with a maximum angular deviation (MAD) value that describes component uncertainty, and MAD values of 15° are typically used as reliability filter (McElhinny & McFadden, 2000), although smaller angles (e.g., 5°, Asefaw et al (2021)) are also used. The total scatter in a paleomagnetic data set then consists of within-site and between-site scatter (McElhinny & McFadden, 1997), whereby the uncertainties in paleomagnetic directions or VGPs are typically not propagated through the different levels of the hierarchical framework and directions/VGPs are typically given unit weight in the calculation of a mean direction/paleopole (e.g., Heslop & Roberts, 2020;Irving, 1964).…”

Section: Introductionmentioning

confidence: 99%

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Influence of Data Filters on the Position and Precision of Paleomagnetic Poles: What Is the Optimal Sampling Strategy?

Gerritsen

Vaes

Hinsbergen

2022

Geochem Geophys Geosyst

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Paleomagnetic poles, or paleopoles, quantify the past position of rocks relative to the geomagnetic pole and constrain tectonic reconstructions and apparent polar wander paths (APWPs; e.g., Besse & Courtillot, 2002;Torsvik et al., 2012). The calculation of paleopoles relies on the assumption that the time-averaged geomagnetic field approximates a geocentric axial dipole (GAD), but is complicated by short-term deviations from this field (e.g., Cromwell et al., 2018; Oliveira et al., 2021) known as paleosecular variation (PSV). To obtain a paleopole, paleomagnetists therefore average virtual geomagnetic poles (VGPs), whereby every VGP is then assumed a "spot reading": an instantaneous reading of the past geomagnetic field collected from a rock unit ("site") that represents an increment of geological time, such as a lava flow (Butler, 1992;Tauxe et al., 2010). However, not every VGP represents an accurate spot reading because artifacts may be introduced by measuring errors or remagnetization (e.g., Bilardello et al., 2018;Butler, 1992;Irving, 1961Irving, , 1964. Therefore, the paleomagnetic community commonly uses a set of data filters to acquire a set of reliable spot readings and to objectively eliminate outliers and unreliable data. However, these filters vary between authors and were not determined by studies aiming to constrain paleopoles.The studies that established the data filters, investigated PSV and geomagnetic field behavior by determining the between-site scatter of a set of VGPs (e.g.,

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Section: Datasets and Approachmentioning

confidence: 99%

Section: Datasets and Approachmentioning

confidence: 99%

Section: Datasets and Approachmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Influence of Data Filters on the Position and Precision of Paleomagnetic Poles: What Is the Optimal Sampling Strategy?

Gerritsen

Vaes

Hinsbergen

2022

Geochem Geophys Geosyst

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Paleointensity Estimates From the Pleistocene of Northern Israel: Implications for Hemispheric Asymmetry in the Time‐Averaged Field

Tauxe

Asefaw

Behar

et al. 2022

Geochem Geophys Geosyst

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Twenty‐two sites, subjected to an IZZI‐modified Thellier‐Thellier experiment and strict selection criteria, recover a paleomagnetic axial dipole moment (PADM) of 62.2 ± 30.6 ZAm2 in Northern Israel over the Pleistocene (0.012–2.58 Ma). Pleistocene data from comparable studies from Antarctica, Iceland, and Hawaii, re‐analyzed using the same criteria and age range, show that the Northern Israeli data are on average slightly higher than those from Iceland (PADM = 53.8 ± 23 ZAm2, n = 51 sites) and even higher than the Antarctica average (PADM = 40.3 ± 17.3 ZAm2, n = 42 sites). Also, the data from the Hawaiian drill core, HSDP2, spanning the last half million years (PADM = 76.7 ± 21.3 ZAm2, n = 59 sites) are higher than those from Northern Israel. These results, when compared to Pleistocene results filtered from the PINT database (http://www.pintdb.org) suggest that data from the Northern hemisphere mid‐latitudes are on average higher than those from the southern hemisphere and than those from latitudes higher than 60°N. The weaker intensities found at high (northern and southern) latitudes therefore, cannot be attributed to inadequate spatiotemporal sampling of a time‐varying dipole moment or low quality data. The high fields in mid‐latitude northern hemisphere could result from long‐lived non‐axial dipole terms in the geomagnetic field with episodes of high field intensities occurring at different times in different longitudes. This hypothesis is supported by an asymmetry predicted from the Holocene, 100 kyr, and 5 million year time‐averaged geomagnetic field models.

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MCADAM: A Continuous Paleomagnetic Dipole Moment Model for at Least 3.7 Billion Years

Bono

Paterson

Biggin

2022

Geophysical Research Letters

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The evolution of Earth's deep interior since core formation (Nimmo, 2015) >4 billion years ago (Ga) remains a topic of considerable study. Obtaining information of the deep interior is generally restricted to present-day observations. Alternatively, insights on processes occurring before the modern era require sampling geologic materials that formed at, or were transported to, Earth's surface. However, the geomagnetic field is generated in the liquid fraction of Earth's core through the geodynamo, and changes in the morphology, strength and variability in the geodynamo may reflect the evolution of core processes and the pattern of heat flux across the core-mantle boundary. The geomagnetic field is also a critical component for Earth's habitability (Rodríguez-Mozos & Moya, 2017) due to the protective envelope provided by the magnetosphere against atmospheric erosion by charged solar particles. It is speculated that changes in the paleomagnetosphere may have contributed to substantial changes in the evolution of life (e.g., Meert et al., 2016).Paleomagnetic studies offer the potential to help close this gap: when rocks bearing magnetic carriers form, the geomagnetic field imparts a remanent magnetization that under ideal circumstances can be robustly preserved for billions of years. The strength of the geodynamo can be described by the magnitude of the dipole moment, the first-degree spherical harmonic component of the field, which should reflect ∼90% of the surface field signal. A fundamental question regarding Earth's dynamo is how the dipole moment has changed over long timescales (≫millions of years). Paleointensities measured from the same geologic time (e.g., from the same cooling-unit, referred to as a "site") can be related to paleointensities from other locations by transforming the paleointensity (B) into a virtual (axial) dipole moment (V(A)DM) using the following equation (Smith, 1967):

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Four‐Dimensional Paleomagnetic Dataset: Plio‐Pleistocene Paleodirection and Paleointensity Results From the Erebus Volcanic Province, Antarctica

Cited by 9 publications

References 81 publications

Influence of Data Filters on the Position and Precision of Paleomagnetic Poles: What Is the Optimal Sampling Strategy?

Influence of Data Filters on the Position and Precision of Paleomagnetic Poles: What Is the Optimal Sampling Strategy?

Paleointensity Estimates From the Pleistocene of Northern Israel: Implications for Hemispheric Asymmetry in the Time‐Averaged Field

MCADAM: A Continuous Paleomagnetic Dipole Moment Model for at Least 3.7 Billion Years

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