Herrero Bervera, E.

Tema, Evdokia

English

Institutional Research Information System University of Turin

Tuesday, 15 December 201513:40 - 18:00Moscone South - Poster HallHawaii is an ideal place to study the secular variation (SV) of the Earth's magnetic field in centralPacific region, thanks to its long and continuous volcanic activity. We present here a compilation ofwell-dated palaeomagnetic data from Hawaiian lava flows that allow a complete description of the fullgeomagnetic field vector (declination, inclination and intensity) in this area. All available radiocarbonages have been uniformly calibrated using the IntCal13 calibration curve and the most probableradiocarbon ages have been used for further considerations. A total of 323 directional and 98intensity data have been collected for the last 10 000 years, most of them coming from the Big Island(data from lava cores have not been included). The data cover almost continuously the last 5millennia while data from older periods are still scarce. The directional data are well consistent witheach other while the intensity data are less abundant and show a higher dispersion. For the last 5000years, where the majority of the data are concentrated, continuous secular variation curves for bothdirection and intensity have been calculated using the moving window technique with windows of 200years shifted by 100 years. The obtained curves clearly show some characteristic features of thegeomagnetic field variation in the central Pacific. Low inclination values are well documented around500 AD, 1000 BC and 2500 BC while high inclinations are observed around 3000 BC and 1500 AD.Declination shows an eastward trend from 1000 AD to the present while a declination low isregistered around 500 BC. The intensity curve is highly influenced by the important dispersion of thereference data points. The obtained curves have been compared with the predictions of theCALS10k.1b and pfm9k.1a global geomagnetic field models. Such comparison shows a good generalagreement even though the models show much smoother variations mainly regarding intensity.Nevertheless, both the Hawaiian SV curves and the pfm9k.1a model show abrupt variations in bothdirection and intensity of the field around 300-100 BC which seems to be a very interesting feature ofthe geomagnetic field in the Pacific region.AuthorsEvdokia TemaUniversity of TurinEmilio Herrero-BerveraUniversity of Hawaii at ManoaView Related EventsSession: Reconstructing the Secular Variation of the Earth's Magnetic Field in the Past: RecentMethodological Advances and New Palaeomagnetic and Archaeomagnetic Data III PostersGP23A-1293: Full Vector Geomagnetic Field Variation during the Holoceneregistered by Hawaiian Lava Flow2015 AGU Fall Meeting https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/652971 of 2 12/01/15 12:04 PMSection/Focus Group: Geomagnetism and PaleomagnetismDay: Tuesday, 15 December 20152015 AGU Fall Meeting https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/652972 of 2 12/01/15 12:04 PM

Full vector geomagnetic field variation during the Holocene registered by Hawaiian lava flows

https://iris.unito.it/bitstream/2318/1567118/1/2015%20AGU%20Fall%20Meeting_Abstract%20Hawaiian%20data.pdf

Full vector geomagnetic field variation during the Holocene registered by Hawaiian lava flows

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