He is known as the father of seismology and is noted for his explanation of the Lisbon Earthquake of 1755 using math instead of religion.
He created the first seismometer using pendulums. The seismometer functioned by recording the relative motion of the two pendulums to the Earth.
He was an influence to modern seismology because of his attempts to determine the velocity of a seismic waves in 1906.
He was a geologist with little passion yet was the first to discover p-waves and s-waves in seismograms. He also discovered the Earth's core using seismic waves.
He used a horizontal pendulum to measure the changes of gravity in the Earth when he discovered it actually swung to seismic waves of an earthquake in Japan. He was the first to take a measurement from such a great distance.
Inge Lehmann was from Denmark and was the discoverer of the Earth's inner core. During an earthquake she observed that some P-waves were deflected by the core. She then made her observation that there was something the P-waves bounced off of.
He created the Richter magnitude scale which is still in use now. The scale uses whole numbers and decimals where the amount of energy is thirty-one times the number representation.