Relating to groundwater, especially water in the zone of saturation beneath the earth’s surface, often affecting caves or eruptions.

This year, July 10 was measured as the shortest day of the year, with a full rotation occurring 1.36 milliseconds faster than normal. Aug. 5 is expected to be the third-shortest day of the year ...

Tuesday, July 22 will be the second-shortest day of the year, as Earth completes a full rotation in less time than usual. The planet on Tuesday will experience a shorter rotation than the typical ...

Until 2020, the shortest "length of day" ever recorded by atomic clocks was -1.05 ms, meaning that Earth completed one daily rotation in 1.05 milliseconds less than 86,400 seconds.

In fact, experts say Tuesday, July 22, could end up being the shortest day of all of 2025. If that sounds familiar, it's because an earlier day in July was also expected to be uncharacteristically ...

The next two shortened days, though, will be be even more truncated. Scientists predicted a -1.38 ms "length of day" July 22, and a -1.51 ms "length of day" Aug. 5.