1889-1960

German-American geophysicist who demonstrated Earth's outer core to be liquid and calculated the boundary between it and the solid mantle above to be at a depth of 2,900 km (1,802 miles), now called the Gutenberg discontinuity. In collaboration with Charles Richter, Gutenberg worked to derive more accurate earthquake travel time curves, redetermine major earthquake epicenters, and to quantify interrelationships between magnitude, intensity, energy, and acceleration of vibrations within the earth. Gutenberg also extended the Richter scale to deep-focus shocks.