Results 31 to 40 of about 519 (182)

Consistent and Contrasting Aspects of the Geomagnetic Field Across Epochs With Distinct Reversal Frequencies Revealed by Modeling the Kiaman Superchron

Geochemistry, Geophysics, Geosystems, 2021
This work presents an extensive directional paleomagnetic database of the Kiaman reversed superchron. It is composed of 1,459 paleomagnetic directions from igneous rocks corresponding to 91 data sets (or paleomagnetic poles).
Daniele Brandt, Marcia Ernesto, Catherine Constable   +2 more
doaj   +1 more source

Persistent shallow magnetic inclination in the past 5 million years with implications for regional tectonics in the Philippines

Journal of Asian Earth Sciences: X, 2021
Despite the growing knowledge on geomagnetic paleosecular variations, the region around the Philippine archipelago remains to be a huge data gap in this regard. This work looked into rock magnetic information from
Decibel V. Faustino-Eslava, Hidetoshi Shibuya, Carla B. Dimalanta, Graciano P. Yumul, Jr., Jonathan T. Macuroy   +4 more
doaj   +1 more source

More stable yet bimodal geodynamo during the Cretaceous superchron?

Geophysical Research Letters, 2016
We report palaeomagnetic and 40Ar/39Ar dating results from two sequences of basaltic lava flows deposited at the same locality in western China, yet separated in time by ~50 Myr: one set lies within the Cretaceous normal superchron at 112–115 Ma and a ...
Florian Lhuillier, Stuart A. Gilder, Michael Wack, Kuang He, Nikolai Petersen, Brad S. Singer, Brian R. Jicha, Allen J. Schaen, Dylan Colon   +8 more
doaj   +1 more source

Mapping the Gauss Coefficients to the Pole and the Models of Paleosecular Variation.

Journal of geomagnetism and geoelectricity, 1995
The present magnetic field is usually described by models such as the IGRF which are described by Gauss coefficients obtained by spherical harmonic analysis of the geomagnetic field. The use of Gauss coefficients in paleosecular variation (PSV) studies will therefore make it possible to compare field structures obtained through paleomagnetism with ...
Kono, Masaru, Tanaka, Hidefumi
openaire   +2 more sources

New Archeomagnetic Directional Records From Iron Age Southern Africa (ca. 425–1550 CE) and Implications for the South Atlantic Anomaly

Geophysical Research Letters, 2018
The paucity of Southern Hemisphere archeomagnetic data limits the resolution of paleosecular variation models. At the same time, important changes in the modern and historical field, including the recent dipole decay, appear to originate in this region ...
Vincent J. Hare, John A. Tarduno, Thomas Huffman, Michael Watkeys, Phenyo C. Thebe, Munyaradzi Manyanga, Richard K. Bono, Rory D. Cottrell   +7 more
doaj   +1 more source

Paleomagnetic evidence for episodic construction of the Mamiyadake tephra ring

Earth, Planets and Space, 2023
Tephra rings that surround maar craters are typically inferred from field observations to have been emplaced rapidly over a time period of days to years and thus monogenetic, which is, however, rarely assessed quantitatively.
Yuki Yasuda
doaj   +1 more source

Black Sea paleosecular variation stack between 68.9 and 14.5 ka

, 2020
A full vector paleomagnetic record, comprising directional data and relative paleointensity (rPI), were derived from 16 sediment cores recovered from the southeastern Black Sea.
Liu, Jiabo, Arz, Helge Wolfgang, Nowaczyk, Norbert R   +2 more
core   +1 more source

Persistent high paleosecular variation activity in southern hemisphere for at least 10 000 years

, 2016
Direct observations of the geomagnetic field show that secular variation is strong in the Atlantic hemisphere, and comparatively reduced in the Pacific region. The dipole has been decaying since at least 1840 AD, driven by growth and migration of reverse
Constable, Catherine, Panovska, Sanja, Korte, Monika   +2 more
core   +1 more source

Secular variation and excursions of the Earth magnetic field during the Plio-Quaternary: New paleomagnetic data from radiometrically dated lava flows of the Colima volcanic complex (western Mexico)

Revista Mexicana de Ciencias Geológicas, 2018
Detailed rockmagnetic and paleomagnetic investigations were performed on selected lava flows from the Colima volcanic complex (CVC) located in the western sector of the Trans-Mexican Volcanic Belt. Reliable paleomagnetic directions were obtained from 21
Rafael García-Ruiz, Avto Goguitchaichvili, Miguel Cervantes-Solano, Abel Cortés-Cortés, Juan Morales-Contreras, Rafael Maciel-Peña, José Rosas-Elguera, José Luis Macías-Vázquez   +7 more
doaj   +1 more source

Hydrodynamic variations and human activities have influenced sediment fluxes in the pearl river delta since the late holocene

Frontiers in Earth Science, 2023
Climate change and human activity can both exert a role in the river discharge and sediment load in river deltas when the sea level remains relatively stable.
Xiaoqiang Yang, Shuang Wu, Shentang Shang, Yan Chen   +3 more
doaj   +1 more source