In December 2021, the agonic line crossed the Royal Observatory of Madrid on its westward drift. The previous crossing by the agonic line, drifting eastward, is not accurately dated because declination measurements of that time are scarce. After collecting the data obtained in the Iberian Peninsula over the last 500 years and reducing them to ROM coordinates, a geomagnetic declination curve was generated. As a result, the previous cross ing been the agonic line was dated around the year 1652.

The DC-powered service of the Berlin suburban railways disturbed the observations in Potsdam and Seddin. A suitable location for the establishment of a new observatory was found near the small town of Niemegk. The "Adolf-Schmidt-Observatorium für Erdmagnetismus Niemegk" was officially opened on 23 July 1930, Adolf Schmidt’s 70^th.  The observations started on 1 January 1932. The Niemegk measurement series spans 92 years, only interrupted at the end of World War II.

This paper deals with historical auroral photographs taken at the Sodankylä Geophysical Observatory (Finland) in 1927–1929. These photos are the first ones taken in Finland. The work was a co-operation with the Norwegian auroral team and Carl Störmer. The auroral material was recently found in the archive of the Finnish Meteorological Institute and is now published for the first time for the international scientific community.

Due to anthropogenic disturbances on the Potsdam Magnetic Observatory, a sub-observatory was installed in 1907 in the village of Seddin. Only variometer recordings were performed there. The launch of the DC-powered service of the Berlin suburban railway in 1928 influenced the observations in Potsdam and Seddin. The absolute measurements were moved to Seddin, and a new observatory was planned in Niemegk. Seddin Observatory closed in 1932.

Gauß, Weber and Humboldt initiated the systematic observation of the Earth’s magnetic field in Germany. The first geomagnetic observatories were installed in Munich, Berlin and Wilhelmshaven. The Potsdam Magnetic Observatory was officially opened on 1 January 1890. Due to anthropogenic disturbances, a sub-observatory was installed in 1907 in the village of Seddin. The launch of the DC-powered service of the Berlin suburban railway system in 1928 terminated the observations in Potsdam.

Kakioka Magnetic Observatory (KMO) has been monitoring the geomagnetic field and electric field at Kakioka, Japan, since 1913. It has promoted a variety of observations and research activities. In 1972, KMO developed the Kakioka Automatic Standard Magnetometer (KASMMER) system, which enabled them to provide geomagnetic field data of the highest quality. Today, KMO operates a network of observatories in Japan and maintains the observations with the longest history in East Asia.

This paper is a paraphrased summary of the book published in Finnish on the 100th anniversary of the Sodankylä Geophysical Observatory in 2013 (edited by Heikki Nevanlinna, 2017). The history of the Geophysical Observatory in Sodankylä (SGO) is described by the personalities who have run it and have shaped the observatory. Thereafter, we describe the history from a technical point of view, i.e., what the measurements were and which instruments were primarily used at the observatory.

From the perspective of the social history of science and transnational history, this paper reviews the development of the Institute of Geophysics at the Chinese Academy of Sciences (IGCAS). The scientific development of IGCAS and typical examples in several branches of geophysics, which include atmospheric science, seismology, and space physics, are summarized. The experience and lessons in the development of this institute and its effect on geophysics in China are explored.

The historical development of the Geophysical Service of Austria, comprising the national geomagnetic, gravimetric and seismological services as well as the Applied Geophysics Section located at the Zentralanstalt für Meteorologie und Geodynamik (ZAMG) in Vienna in Austria, is presented. Achievements, changes and challenges of the department from its modest beginning in 1851 until 2020 are described, including the Conrad Observatory.

A historical review of the establishment of the Haldde Observatory in Bossekop, Kaafjord, Finnmark, in northern Norway is presented together with some of the scientific outcomes of the efforts and the aftermath of this enterprise that led to the establishment of the University of Tromsø in 1968 and finally the inauguration of the Haldde Observatory as a historic site by the European Physical Society in 2018.

Researching, compiling and analysing geophysical ideas and measurements in historical periods will contribute to the historical development of earth science. Also, this is important for geophysicists working on time-dependent (historical) data and revealing the physical properties of the earth. This paper focuses on the earth and its sciences (with concepts, ideas and measurements) in classical Islamic science in the Ottoman Empire and the evolution of these thoughts and concepts.

The Jicamarca Radio Observatory is a research facility of the Geophysical Institute of Peru, located near the city of Lima, that has been conducting observations and studies of the equatorial ionosphere for more than 50 years. In these notes we focus to the period of its construction and roughly the first decade of its operation (1960–1974). We emphasize observational and instrumental developments that shaped the capabilities of one of the most powerful incoherent scatter radars in the world.

The article describes the history of Andøya Rocket Range (now Andøya Space Center) from its inception in 1962 until today. From the first sounding rocket launch, ARR/ASC has developed into an important company on both the national and international scene. Its activities encompass scientific studies of the Arctic upper atmosphere with sounding rockets and advanced ground-based instruments, education in space science and technology, and technological services required for such activities.

In this paper a brief summary will be given of 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 with a wide range.

This paper discusses an historical record of the ocean tide made by the astronomer Manuel Johnson (a future President of the Royal Astronomical Society) at St. Helena in 1826–27. It describes how the measurements were made using a tide gauge of an unusual design, which recorded the heights of the high and low tides well, although information on their times were not so accurate. Johnson’s work is not well known. One objective of the present research was to make his measurements more accessible.

Colonial era Colaba-Alibag MO, operational since 1841, contains valuable information on geomagnetic phenomena of different periodicities. First Indian director Nanabhoy Moos compiled Colaba data and interpreted them radically differently, echoing current understanding. Moos rejected terrestrial origins for magnetic storms and tried to bind together meteorological, seismological and geomagnetic realms. Colaba instruments have historical and scientific significance. Move to Alibag was incidental.