Richard Dixon Oldham is credited with discovering the two main types of body waves -- elastic shock waves that travel through the Earth during earthquakes. The first of these waves is called a P , or Primary wave, because, due to its rate of...

1858-1936 Irish geologist and seismologist who established the existence of Earth's core. Based on his landmark survey of the 1897 Assam earthquake, Oldham identified three types of seismic waves—primary (P-waves), secondary (S-waves),...

Richard Dixon Oldham (July 31, 1858 – July 15, 1936) was an Irish geologist who, in 1906, argued that the Earth must have a molten interior as S waves were not able to travel as quickly through liquids nor through the Earth's interior as through...