One of the main geysers in the Lower Geyser Basin is Clepsydra Geyser, named for an ancient Greek word for water clock. When this geyser was named it erupted regularly at three minute intervals. It was altered during the 1959 earthquake and went into a "wild phase"; erupting almost continuously. It only pauses if nearby Fountain Geyser is active (a geyser that "reactivated" in the 1990s).