Inge Lehmann: Danish Seismologist and Discoverer of the Earth’s Inner Core
Early Life and Education:
Inge Lehmann was born on May 13, 1888, in Østerbro, a district of Copenhagen, Denmark. Growing up in a family that valued education, she showed an early aptitude for mathematics and physics. Lehmann attended the Øster Farimagsgade School in Copenhagen and later enrolled at the University of Copenhagen, where she studied mathematics, physics, and chemistry.
In 1920, she earned her master’s degree in physical science and mathematics, and she continued her academic pursuits by attending the University of Cambridge in England to study under Sir Arthur Schuster.
Return to Denmark and Seismological Work:
In 1923, Lehmann returned to Denmark and began working at the Geodetic Institute of Denmark, where she became involved in seismological research. At that time, seismology was a relatively young field, and Lehmann’s work focused on analyzing seismic waves produced by earthquakes to understand the Earth’s interior.
Her initial research involved examining seismograms from distant earthquakes recorded in Denmark. In 1928, Lehmann published a paper on the P-wave shadow zone, an area on the Earth’s surface where P-waves (primary or compressional waves) from earthquakes were not detected. This phenomenon provided crucial information about the structure of the Earth’s interior.
Discovery of the Earth’s Inner Core:
In the early 1930s, while studying seismic waves from large earthquakes, Lehmann made a groundbreaking discovery. She observed that P-waves produced by earthquakes exhibited unexpected behavior as they traveled through the Earth’s core. Lehmann deduced the presence of a solid inner core within the Earth, distinct from the surrounding liquid outer core.
In 1936, Lehmann published her seminal paper, “P’, in which she presented her evidence for the existence of the Earth’s inner core. This discovery fundamentally changed scientists’ understanding of the Earth’s internal structure.
Career and Recognition:
Inge Lehmann continued her research at the Geodetic Institute, and in 1953, she became the institute’s director. She remained in this position until her retirement in 1958. Throughout her career, Lehmann’s contributions to seismology earned her international recognition.
In 1971, she received the Gold Medal of the Royal Astronomical Society, and in 1977, she was awarded the Emil Wiechert Medal of the German Geophysical Society. Lehmann’s work laid the groundwork for further advancements in the field of seismology and deepened our understanding of the Earth’s interior.
Legacy and Later Life:
Inge Lehmann’s legacy endures as one of the pioneering figures in seismology. Her discovery of the Earth’s inner core was a pivotal contribution to the understanding of the planet’s structure and dynamics.
Inge Lehmann passed away on February 21, 1993, in Copenhagen, Denmark, leaving behind a lasting impact on the field of geophysics. Her dedication to scientific inquiry and her groundbreaking contributions to seismology have solidified her place as a trailblazer in the study of the Earth’s interior.
