Sekiya Seikei (関谷 清景, 28 January 1855 – 8 January 1896), alternatively Sekiya Kiyokage, was a Japanese geologist, one of the first seismologists, influential in establishing the study of seismology in Japan and known for his model showing the motion of an earth-particle during an earthquake.

[2] In this position, he helped in the extension of the seismic survey in Japan and in the erection of seismographs throughout the country.

The wire diagram gives an illustration of the complicated movements of the ground during an earthquake, conveying the complexity of ground motion, both in terms of the vagaries of its geometric path and in its erratic accelerations.

Sekiya's original copper-wire model now resides in the Whipple Museum of the History of Science at Cambridge University.

"[5] After spending several months studying the new crater and the devastated areas subsequent to 1888 eruption of Mount Bandai, he published together with Y. Kikuchi a report in English (“The eruption of Bandai-san” Tokyo Imperial University College of Sciences Journal 3 (1890), pp 91–171), which is considered a classic in volcanology.