Hermanus Magnetic Observatory: a historical perspective of geomagnetism in southern Africa

Pieter B Kotzé

doi:10.5194/hgss-9-125-2018

Abstract

Abstract. In this paper a brief summary will be given about the historical development of geomagnetism as a science in southern Africa and particularly the role played by Hermanus Magnetic Observatory in this regard. From a very modest beginning in 1841 as a recording station at the Cape of Good Hope, Hermanus Magnetic Observatory is today part of the South African National Space Agency (SANSA), where its geomagnetic field data are extensively used in international research projects ranging from the physics of the geo-dynamo to studies of the near-Earth space environment.

Highlights

IntroductionThe requirements of navigation during the era of exploration, rather than any scientific interest in geomagnetism, prompted the recording of geomagnetic field components at the Cape of Good Hope even before 1600 (Kotzé, 2007)
The requirements of navigation during the era of exploration, rather than any scientific interest in geomagnetism, prompted the recording of geomagnetic field components at the Cape of Good Hope even before 1600 (Kotzé, 2007).The importance of knowledge regarding the deviation of a compass needle from true north was sufficient motivation to establish a geomagnetic field recording station at the Cape in 1841
2 The early history of 1600 till 1932. This overview of geomagnetism and its historical development in southern Africa covers a period of approximately 400 years till present (Kotzé, 2007, 2015)

Summary

Introduction

The requirements of navigation during the era of exploration, rather than any scientific interest in geomagnetism, prompted the recording of geomagnetic field components at the Cape of Good Hope even before 1600 (Kotzé, 2007). INTERMAGNET (http://www.intermagnet.org, last access: 16 May 2018) observatories at Hartebeesthoek, Tsumeb and Keetmanshoop enable studies of secular variation patterns over southern Africa and the influence of the South Atlantic Magnetic Anomaly (e.g. Pavón-Carasco and De Santis, 2016) on the characteristics of the global geomagnetic field. This is a region where the Earth’s magnetic field is approximately 25 % weaker than at similar latitudes around the globe, allowing energetic particles from the radiation belts to penetrate the atmosphere to very low altitudes. The regional monitoring and research of the geomagnetic field in southern Africa are important in understanding the time-varying South Atlantic Anomaly and its subsequent influence on the morphology of the global field

The early history of 1600 till 1932

Magnetic field observations in southern Africa

Activities in other areas and disciplines

Science activities