Timeline/Background Information

International Geophysical Year Logo https://www.nasa.gov/centers-and-facilities/johnson/65-years-ago-the-international-geophysical-year-begins/

July 1, 1957: Official Commencement of the Internation Geophysical Year

On July 1, 1957, the International Geophysical Year officially began, launching an 18-month period of synchronized global observation involving scientists from 67 nations. This massive endeavor, proposed by Lloyd Berkner and Sydney Chapman, was timed to coincide with the maximum of solar cycle 19 to observe solar-terrestrial interactions. The collaboration bridged Cold War divides, facilitated the free exchange of data through newly created World Data Centers, and laid the political and scientific groundwork for the Antarctic Treaty signed in 1959 (Korsmo, 2007; O’Connell, 2020; Uri, 2022).

IGY research stations in the Arctic by participating countries. Image Credit: (Lyubovtseva et. al., 2020)

1957-1958: Meteorology

During the IGY, the goal of meteorology research was to get more information across the globe to provide more accurate estimates of global weather patterns, wind systems and movement of atmospheric energy (Wexler, 1957). By May 1957 there was over 1603 functioning meteorology research stations and this number increase to almost 4000, that exchanged observational data (Martin, 1958). The stations were equipped with instruments for measuring ozone, silver clouds, and atmospheric electricity at high altitudes for comprehensive research on a variety of meteorological topics (Lyubovtseva et. al., 2020). The stations also launched balloons equipped with weather instruments that could return information to Earth. These stations drastically increase the ability to understand and predict weather by furthering technology and knowledge that allows for more precise weather monitoring (Lemaire, 2021). All of this collaborative research has since led to significant advancements in meteorology.

American and Soviet scientists in Antarctica. Image Credit: (Lyubovtseva et. al., 2020)

1958: Anthropogenic Warming

The IGY program included comprehensive research on the composition and chemical transformations in the Earth’s atmosphere, the studies of its radioactivity, the electrical conductivity, the photochemical ozone-productive cycles, aerosol, and carbon dioxide measurements. As a result, there appeared a reasonable assumption that the increases in carbon dioxide, methane, and nitrous oxide levels in the atmosphere are associated with anthropogenic activity (Lyubovtseva et. al, 2020). We can now see the changes in our global climate and the warming since the IGY, in recent research, eventually leading to the proposed Anthropocene. There have been many ways suggested to define the Anthropocene. The Anthropocene Working Group proposed defining it as an epoch with a GSSP in the varve deposited in 1952 at Crawford Lake (McCarthy et al., 2025). This was the location chosen by the Anthropocene Working Group to conduct research on the possible new epoch.

1958: Gravity Measurements

During the IGY, all expeditions in the Arctic and Antarctic made gravity measurements. A major area with limited gravity data was within the oceans, so this became an area for focus during the IGY. On October 16, 1957 measurements on the bottom of the ocean were made with satisfactory results were made using a bathyscaph. Understanding gravity measurements on Earth are important for our knowledge of the interior and shape of the Earth. Satellites can also be used for gravity measurements, something scientists began as a result of further technology after the IGY.

Scientists were able to identify gravity anomalies and gain evidence for other related theories, such as isostasy and eventually plate tectonics. All of the research and measurements taken during the IGY laid better foundation for future investigation into gravity and gravitational processes (Woollard, 1958).

Daily magnetogram on October 4, 1957 at a geomagnetic observatory in Moscow. Image Credit: (Lyubovtseva et. al., 2020)

1957-1958: Geomagnetism

Observations of the Earth's magnetic field were carried out at 276 stations across all parts of the globe, equipped with magnetic variometers and quartz magnetometers. For the first time, observations were made at a height of several hundred kilometers by rockets and satellites (Lyubovtseva et. al, 2020). This extensive research and observation of Earth's geomagnetism lead to the first comprehensive map of earths magnetic field. Additionally, it contributed to the discoveries of Van Allen radiation belts which surround the Earth at hundreds and thousands of kilometers, by the instruments of explorer satellites in 1958 (Britannica, n.d.). Geomagnetic research during the IGY helped with broader understanding of earths processes and physical phenomena.

Diagram of ionosphere affects how radio waves travel through Earth’s atmosphere

Image Credit: NOAA

1957–1958: Ionosphere Physics

The ionosphere corresponds to the upper part of the Earth's atmosphere, extending from approximately 60 km to above 1,000 km. The solar ultraviolet and X-ray spectrum ionizes it. The ionized region can reflect and bend radio wave transmissions. This has made the ionosphere critical for long-distance radio communications and satellite transmission (Kelley, 2009; NASA, 2023). During the IGY, one area that researchers were keen on understanding was the way the ionosphere changed globally due to solar activity, especially with the high solar year of 1957. The IGY provided the first operational global observing system for the ionosphere, integrating ionosondes, radio sounding, sounding rockets, and the early satellites. Such measurements allowed for the detection of organized electron density patterns over latitude, time, and magnetic disturbances (Davies, 1990; Liu et al., 2021). Contemporary research has built upon discoveries from the IGY era, utilizing satellite networks, changes in the ionosphere, and space weather interference with navigation systems, which is being conducted by satellites employing GPS technology. Currently, space weather forecasting algorithms owe their lineage to the global ionosphere, which was created during the IGY.

Auroras are produced by solar particles colliding with gases in Earth’s upper atmosphere

Image Credit: NASA

1957–1958: Auroras

Aurorae are atmospheric light manifestations caused by the interaction of charged particles emitted from the Sun with the Earth’s upper atmosphere along magnetic field lines, leading to excited atoms causing green, red, or violet light, especially found in polar regions (Chamberlain, 1961; Akasofu, 1968). As a consequence of increased auroral activity associated with high levels of solar activity, one of the main reasons for conducting the IGY was to study aurorae from a global perspective within the IGY solar MAXIMUM, when solar activity was at its highest. During the IGY, networks of auroral cameras, magnetometers, and rocket observatories were established around the Arctic and Antarctica. Not only did these observatories show the relationship of auroras to geomagnetic storms and the transport of solar wind energy into the Earth’s magnetic field (Akasofu, 1968; Lockwood, 2019), but they also established the foundation for the current use of auroras in space weather forecasts to shield satellites, communication networks, and the power grid from the effects of geomagnetic storms.

Airglow observed over Auvergne, France, showing faint atmospheric emissions in the upper atmosphere.

Image Credit: Clame Reporter, CC BY-SA 4.0, via Wikimedia Commons

1957–1958: Airglow

Airglow consists of a faint emission of light from chemical reactions in Earth's upper atmosphere that occur over the globe, both in the daytime and nighttime. Unlike in the case of auroras, it does not appear only at high latitudes, but it reflects the ongoing process of energy transfer involving oxygen, nitrogen, and hydroxyl molecules in the mesosphere and thermosphere. Although airglow is subtle to human perception, it brings critical information on the composition, temperature, and circulation pattern of the atmosphere. During IGY, scientists acknowledged airglow as a tool for studying the upper atmosphere on a global scale, particularly during heightened solar activity in 1957. The IGY coordinated ground-based photometers, spectrographs, and sounding rocket experiments that would measure airglow intensity and spectral characteristics at several latitudes. Such observations enabled hemispheric comparisons of atmospheric conditions and the determination of how solar radiation affected upper-atmospheric chemistry and energy balance. By relating airglow measurements to other IGY atmospheric observations, new insights were obtained on atmospheric tides, wave motion, and long-range energy transport. This international effort established foundational knowledge that continues to support modern studies of satellite drag, space-weather interactions, and long-term changes in Earth's upper atmosphere.

Scientists use high-altitude balloons to collect valuable data on cosmic rays.

Image Credit: NASA/BPO

1957: Cosmic Rays

Cosmic Rays are particles that travel across the universe near the speed of light. Originating from supernovas, and produced by our Sun, cosmic rays are constantly bombarding Earth. Luckily for us, they are mostly blocked by the Earth’s atmosphere and magnetic field (Howell, 2023). After the discovery of cosmic rays by Victor Hess in 1912, scientists began to learn the nature of primary and secondary radiation from instrument recordings across the globe. This data collection included using ionization chambers carried by balloons, similar to atmospheric balloon experiments we see today. The IGY coordinated the study of these cosmic rays, timed with the solar maximum in 1957. This way, scientists could study energetic solar particles and their effects along with cosmic rays at the same time. Tracing the trajectories of primary cosmic rays in the Earth’s magnetic field created the precision needed when collecting data across geographic locations. This international collaboration linked observations from data across all different latitudes and altitudes (Stoker, 2009).

Example image of sunspot tracings taken during the IGY.

Image Credit: (Denig, 2016)

1957: Solar Activity

The International Geophysical Year was perfectly timed to coincide with the peak of the 11-year cycle of sunspot activity. We now know this as the solar cycle, driven by the Sun’s magnetic field as it flips around every 11 years, impacting the activity on the surface. The number and location of sunspots change throughout the solar cycle, thus the solar cycle is also called the sunspot cycle (Dobrijevic, 2022). Solar cycle 19, which actually was the strongest solar cycle on record, had the largest observed count of 285 sunspots. The IGY produced systematic global scientific collaboration monitoring sunspots, solar flares, and geomagnetic storms, and linking them to the beautiful auroras we see on Earth (Denig, 2016).

1957: Mapping the Mid-Atlantic Rift Valley

Tharp and Heezen’s Physiographic Map of the North Atlantic Ocean Floor

https://www.lib.uchicago.edu/collex/exhibits/marie-tharp-pioneering-oceanographer/1957-atlantic-ocean-map/

Throughout 1957, geologist Marie Tharp and Bruce Heezen of the Lamont Geological Observatory (Columbia University) produced the first physiographic map of the North Atlantic Ocean floor. By analyzing echo-sounding profiles, Tharp identified a continuous V-shaped rift valley running along the axis of the Mid-Atlantic Ridge, a finding initially dismissed by Heezen, until he correlated it with earthquake epicenter data. This visualization provided critical empirical evidence that the Earth's crust was pulling apart at the ridges, leading directly to the acceptance of plate tectonics and continental drift theory (Heezen et al., 1959; O’Connell, 2021; Tharp, 1999).

Diagram of Seismic Wave Behaviour Through the Interior of the Earth

https://lin0214.wordpress.com/2018/03/18/measuring-the-interior-of-the-earth/

1957–1958: Seismic "X-Raying" of the Earth and Earth Tides

Throughout the IGY, seismologists utilized a standardized global network of instruments to "X-ray" the Earth's interior, refining the model of the planet’s structure into a crust, mantle, and core, while confirming the outer core is liquid by observing the blockage of secondary (S) waves. Furthermore, gravimeters installed globally detected "Earth tides", the daily rise and fall of the solid crust by several inches due to the gravitational pull of the moon and sun, proving the Earth is not a rigid body but a flexible spheroid subject to gravitational stress (Hough, 2008; UNESCO, 1957).

Bathymetric Map of the Arctic Ocean https://www.researchgate.net/figure/nternational-Bathymetric-Chart-of-the-Arctic-Ocean-annotated-with-topographic-capital_fig1_356491895

July 1957 – 1958: Arctic Ocean Heat Budget and Submarine Ridges

From July 1957 through 1958, scientists led by Norbert Untersteiner (University of Washington) and Kenneth Hunkins (Lamont Geological Observatory) aboard Drifting Station Alpha conducted the first comprehensive study of the Arctic sea ice heat budget and ocean floor. They determined that equilibrium ice thickness is maintained by bottom accretion balancing top-surface ablation, and they discovered the Alpha Ridge, a massive submarine mountain range. These findings revolutionized the understanding of the Arctic Basin's topography and the thermodynamic relationship between sea ice and the ocean (Cabaniss et al., 1965; Hunkins, 1960; Untersteiner, 1961).

Model of Sputnik 1.

Image Credit: Courtesy NASA/JPL

October 4th, 1957: First Man-made object in Space

During the IGY, the United States and Soviet Union both announced their intentions on sending satellites into orbit around the Earth. Funny enough, the United States first announced their satellite goal on July 29th, 1955, and only four days later, the Soviet Union did the same. The difference is that while the U.S. worked publicly, the Soviets worked in secret to gain the upper hand in this race. Eventually, Sputnik was successfully launched into orbit on October 4th, 1957. (Uri, 2022).

Laika, the first animal in space, during preflight testing on Sputnik 2.

Image Credit: Courtesy NASA/JPL

November 3rd, 1957: First Animal in Space

The chief designer of the Soviet Union’s early space program, Sergei P. Korolev, was later directed to develop Sputnik 2 carrying the world’s bravest dog, Laika. Sputnik 2 was successfully launched on November 3rd, although poor Laika quickly overheated in the cabin and did not survive the journey (Uri, 2022).

Launch of Explorer 1 on board the Jupiter C rocket designed by Wernher von Braun.

Image Credit: Courtesy NASA/JPL

January 31st, 1958: First Satellite in Orbit with Scientific Equipment

The U.S. was finally successful with the launch of Explorer 1. Sputnik had no scientific equipment on it, whereas the U.S. Explorer 1 included a cosmic-ray detector, five temperature sensors, and two micrometeoroid detectors. This satellite discovered Van Allen trapped radiation belts, revealing the Earth's magnetosphere, due to a lower cosmic ray count than interpreted. Following on May 15th, 1958, Sputnik 3 launched carrying 12 scientific instruments to study the Earth’s upper atmosphere, magnetic fields, radiation environment, and cosmic dust, however the tape recorder failed thus no data was acquired. These rocket and satellite launches famously kickstarted the Space Age, leading to new scientific discoveries, and the development of aerospace technologies (Uri, 2022).

Modern Scientists Visually Analyzing an Ice Core https://www.bas.ac.uk/media-post/how-antarctic-ice-cores-give-us-clues-about-earths-future-climate/

January 1958: Deep Ice Core Drilling at Byrd Station

In January 1958, a team from the U.S. Army Snow, Ice and Permafrost Research Establishment (SIPRE), including glaciologist Anthony Gow and project leader E.W. Marshall, successfully drilled the first deep ice core in Antarctica at Byrd Station to a depth of 309 meters. Using a modified Failing 1500 rotary drill rig with cold compressed air to prevent melting, the team recovered continuous cores that allowed for the detailed stratigraphic analysis of annual snow accumulation and density. This achievement marked the beginning of modern deep ice core science, establishing the techniques necessary to reconstruct Earth’s climate history from entrapped atmospheric gases (Langway, 2008; Patenaude et al., 1959).

Depth cross section of West Antarctic https://www.antarcticglaciers.org/antarctica-2/west-antarctic-ice-sheet-2/marine-ice-sheets/

January 28, 1958: Discovery of the West Antarctic Marine Ice Sheet

During the austral summer of 1957-1958, geophysicist Charles Bentley of the University of Wisconsin led a traverse party from Little America V to Byrd Station, utilizing seismic explosions to sound the depths of the ice. This expedition discovered that the West Antarctic Ice Sheet was much thicker than previously thought (up to 3,000 meters) and that the underlying bedrock lay thousands of meters below sea level, defining it as a "marine ice sheet" susceptible to instability. This work also identified the Bentley Subglacial Trench, the lowest point on Earth's surface not covered by the ocean (Behrendt, 2007; Bentley, 1964; University of Wisconsin-Madison, 2017).

Exaggerated representation of Earth’s pear-shape geodesy https://space.asu.cas.cz/~bezdek/vyzkum/rotating_3d_globe/rotating_3d_globe/private/fig06/rotating_3d_globe_preview_Geoid_height_EGM2008_nmax500_-20_-5_px0650.png

March 17, 1958: The Pear-Shaped Earth

On March 17, 1958, the U.S. launched Vanguard 1, the first satellite powered by solar cells, equipped with a Minitrack beacon for precise orbital tracking. By analyzing perturbations in the satellite's orbit, John A. O’Keefe, Ann Eckels, and R. K. Squires of NASA discovered that the Earth is not a perfect oblate spheroid but has a distinct third zonal harmonic, often described as "pear-shaped," with the North Pole being slightly higher and the South Pole flatter than previously believed. This geodetic discovery implied significant stress differences in the Earth's interior and a mechanical strength in the mantle greater than previously assumed (NASA, 2015; O'Keefe et al., 1959).

Visualization of Upper and Subsurface Ocean Current Behaviour https://artsandsciences.fsu.edu/article/subsurface-ocean-mixing-near-equator-significantly-affects-climate-understanding

April – June 1958: Mapping the Cromwell Current

During the "Dolphin Expedition" in the spring of 1958, oceanographer John Knauss of the Scripps Institution of Oceanography conducted the first comprehensive measurements of the Pacific Equatorial Undercurrent (Cromwell Current) using modified Roberts current meters and taut-wire buoys. Knauss confirmed that this subsurface current, located at depths of 50 to 100 meters, transports approximately 40 million cubic meters of water per second eastward, comparable to the Gulf Stream, and is a permanent feature of the equatorial circulation rather than a transient phenomenon. This discovery fundamentally altered the understanding of ocean dynamics, revealing the complexity of subsurface circulation and its role in biological productivity (Knauss, 1960; Knauss, 1966; Weisberg, 2001).

Basic Diagram of a Cesium Atomic Clock https://www.britannica.com/technology/atomic-clock

August 1958: Definition of the Atomic Second

In August 1958, William Markowitz of the U.S. Naval Observatory and Louis Essen of the National Physical Laboratory (UK) published results linking the frequency of the cesium atom to Ephemeris Time, utilizing data collected during the IGY via the Markowitz Moon Camera program. By simultaneously observing the moon to determine Ephemeris Time and monitoring cesium clocks, they determined the frequency of the cesium transition to be 9,192,631,770 cycles per second. This finding laid the groundwork for the modern definition of the second (SI unit) adopted in 1967, enabling the precise global time synchronization required for satellite navigation and modern geodesy (Dick, 2020; Jones & McCarthy, 2001; Markowitz et al., 1958).

Front Cover of Atlantic Ocean Atlas of Temperature and Salinity Profiles and Data

https://app.amanote.com/v4.5.10/research/note-taking?resourceId=zqEm4nMBKQvf0BhixrV0

1960 (Post-IGY): Publication of Atlantic Ocean Temperature and Salinity Atlas

By the end of the IGY, oceanographers had collected enough standardized data to allow Frederick Fuglister of the Woods Hole Oceanographic Institution to compile the Atlantic Ocean Atlas of Temperature and Salinity Profiles. This work provided the first comprehensive, synoptic visualization of the Atlantic's hydrography, mapping the distinct "signatures" of water masses such as the Antarctic Bottom Water and North Atlantic Deep Water. These profiles were essential for establishing the modern understanding of the thermohaline circulation (the global conveyor belt) and for providing a 1950s baseline against which modern ocean warming is measured (Fuglister, 1960; Roemmich et al., 2012).