Inge Lehmann: the Danish scientist who discovered Earth has a solid inner core

[Judi Lynn]

Between 1929 and 1939, seismologist Inge Lehmann compared various data sets from earthquakes to conclusively prove what was at the Earth's core.

By Brian Clegg
29th May, 2020 at 00:00

On 17 June 1929, at around 10:17 local time, a 7.3-magnitude earthquake struck the South Island of New Zealand. Waves from the quake were recorded on seismometers around the world, notably in Frankfurt, Copenhagen, Baku, Sverdlovsk and Irkutsk.

These devices consisted of a heavy weight, suspended from a frame.

When the Earth and the frame vibrated, the inertia of the weight prevented it from moving with them, creating a difference in motion that could be captured by a pen on a rolling sheet of paper.

The first accurate seismometers responded to up and down movements in a horizontal arm, but shortly before the New Zealand earthquake, a new kind of seismometer using a vertically suspended weight came into play, and these proved crucial in the discovery.



More:
https://www.sciencefocus.com/planet-earth/inge-lehmann-who-discovered-earth-has-a-solid-inner-core/

[bobbieinok]

1. Thanks for posting. Info about yet another 'unknown' woman scientist

[bobbieinok]

2. Wow! She lived to be over 104----1888 to1993 per wikipedia

[soothsayer]

3. Awesome