GEOMAGIA50.v3: 1. general structure and modifications to the archeological and volcanic database

Abstract

Background: GEOMAGIA50.v3 is a comprehensive online database providing access to published paleomagnetic, rock magnetic, and chronological data from a variety of materials that record Earth's magnetic field over the past 50 ka.Findings: Since its original release in 2006, the structure and function of the database have been updated and a significant number of data have been added. Notable modifications are the following: (1) the inclusion of additional intensity, directional and metadata from archeological and volcanic materials and an improved documentation of radiocarbon dates; (2) a new data model to accommodate paleomagnetic, rock magnetic, and chronological data from lake and marine sediments; (3) a refinement of the geographic constraints in the archeomagnetic/volcanic query allowing selection of particular locations; (4) more flexible methodological and statistical constraints in the archeomagnetic/volcanic query; (5) the calculation of predictions of the Holocene geomagnetic field from a series of time varying global field models; (6) searchable reference lists; and (7) an updated web interface. This paper describes general modifications to the database and specific aspects of the archeomagnetic and volcanic database. The reader is referred to a companion publication for a description of the sediment database. Conclusions:The archeomagnetic and volcanic part of GEOMAGIA50.v3 currently contains 14,645 data (declination, inclination, and paleointensity) from 461 studies published between 1959 and 2014. We review the paleomagnetic methods used to obtain these data and discuss applications of the data within the database. The database continues to expand as legacy data are added and new studies published. The web-based interface can be found at http:// geomagia.gfz-potsdam.de.

Solar activity during the Holocene: the Hallstatt cycle and its consequence for grand minima and maxima

“…Here we used the GEOMAGIA50.v3 database (Donadini et al 2006;Korhonen et al 2008;Brown et al 2015) to which we added recent archeo-and paleointensity results (Cai et al 2014(Cai et al , 2015Cromwell et al 2015;de Groot et al 2015;Di Chiara et al 2014;Gallet et al 2008Gallet et al , 2009Gallet & Al Maqdissi 2010;Hong et al 2013;Kapper et al 2015;Kissel et al 2015;Osete et al 2015;Shaar et al 2015;Stillinger et al 2015). Concerning the data compiled in this version of GEOMAGIA, the Mesopotamian data from Nachasova & Burakov (1995 were modified according to .…”

“…In addition, and because quite a large number of additional intensity data have recently been collected, an updated mean VADM curve was also produced for the purpose of the present study. For this we used the GEOMAGIA50.v3 data base (Brown et al 2015), to which we added or modified about 390 individual intensity data points (see more details in Appendix A). The new data compilation contains 4764 intensity values dated to between 7000 BC and 2000 AD.…”

The HISTMAG database: combining historical, archaeomagnetic and volcanic data

“…The structure of HISTMAG database is strongly aligned with those of GEOMA-GIA50.v3 (Brown et al 2015a, http://geomagia.gfz-potsdam.de/, last accessed February 2017) and the compilation by Jonkers et al (2003), which contribute the major part to the global data collection. Therefore, we will focus on new database fields describing the records as well as new features of database handling in Section 2, while the technical details and the common metadata framework is presented in the associated manual of HISTMAG database (Supplementary Materials A).…”

“…HISTMAG database is strongly influenced by the main collections regarding historical data from the last ∼500 yr (Jonkers et al 2003) and archaeomagnetic and volcanic records (Brown et al 2015a) covering the last 50 kyr. Therefore, most fields have been adopted from the two compilations.…”

“…Since then, a variety of different palaeointensity protocols as well as quality checks and corrections (for anisotropy, alteration, cooling rate dependence) have emerged. The reader is referred to, for example, Brown et al (2015a) or Paterson et al (2014), and references therein for a detailed discussion.…”