10Be flux in Antarctica during the last 800 000 years and interpretation
type: Dataset
description: The polar ice cores, in addition to improving our understanding of the climate, give access to beryllium-10 (10Be) fallout, an isotope of cosmogenic origin created by the interaction of Galactic Cosmic Rays with the upper atmosphere. Its production rate depends on the intensity of the primary cosmic rays, which are modulated by solar activity and the Earth's magnetic field. 10Be therefore provides information on these two parameters. It has allowed, among others, the improvement of ice cores chronologies thanks to absolute stratigraphic markers linked to remarkable events of the geomagnetic field as the Laschamp excursion or the Brunhes-Matuyama reversal.EPICA Dome C (75° 06' S, 123° 21' E) is a 3270~m ice core drilled in East Antarctica. It offers a complete climate record over the last 800 000 years (kyr BP). In the framework of the PhD, 2200 10Be samples were measured between 2384 m (269 kyr BP) and 2627 m (355 kyr BP) deep. This continuous sequence provides, on the one hand, the opportunity to study the solar activity during the interglacial period of the Marine Isotope Stage (MIS) 9.3, where the resolution reaches ~20 years. Our results contrast with those during the Holocene, with the noted absence of the de Vries cycle (210 years) in our 10Be profile. On the other hand, this sequence allowed us to verify that the classical estimate of snow accumulation obtained by the dating models of ice cores is correct to within 20% during the succession of glacial – interglacial cycles.These measurements were combined with those previously performed under the responsibility of Grant Raisbeck (publication in preparation). This allows to dispose of a continuous and detailed profile (resolution: 20 to 250 years) between 200 and 800 kyr BP on the EPICA Dome C ice core. The observed 10Be flux variations compare well with changes in the intensity of the geomagnetic field recorded in marine sediments. From this observation, it is possible to propose a synchronization of these pr…
landing page: https://theses.hal.science/tel-00954293
identifier: NNT: 2013PA112199
keyword: activite-solaire
keyword: antarctica
keyword: antarctique
keyword: beryllium-10
keyword: carotte-de-glace
keyword: champ-magnetique-terrestre
keyword: climat
keyword: climate
keyword: earth-magnetic-field
keyword: ice-core
keyword: infoeu-reposemanticsdoctoralthesis
keyword: sdustusciences-of-the-universe-physicsearth-sciences
keyword: solar-activity
keyword: theses
issued: 2026-05-06T04:24:22.823395
modified: 2026-05-06T04:24:22.823401
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

10Be flux in Antarctica during the last 800 000 years and interpretation
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00954293
issued: 2026-05-06T04:24:22.853307
modified: 2026-05-06T04:24:22.808732