Scientists Use Sandia’s Z Machine to Probe Early Earth Water Retention

At Sandia National Laboratories in Albuquerque, New Mexico, the Z machine generated a brief but immense electrical pulse that produced pressures comparable to those inside giant gas planets. Alisha Clark of the University of Colorado Boulder used this capability to study the behavior of water-laden molten glass as a stand-in for early Earth’s silicate melt. Her experiments showed that, under extreme pressure, the water-rich glass stiffens initially but then becomes easier to compress, a counter-intuitive response that could allow molten rock to lock in water.

This finding supports an alternative hypothesis that Earth’s original water was largely retained during its molten “magma ocean” stage, later released through volcanic activity. The work challenges the dominant view that Earth’s water arrived mainly from later cometary and asteroidal impacts. Only about ten percent of the Z machine’s annual shots are allocated to fundamental research, making this study a rare application of the device to planetary science.