FIGURE 1: An array of sampling technologies were utilized
in the VERTIGO program to follow the fate of particles sinking from sunlit
surface waters through the ocean’s dimly lit twilight zone. In particular, Ken Buesseler and engineer Jim
Valdes designed a new-generation neutrally buoyant untethered vehicle called
the Twilight Zone Explorer, that is swept along with the currents and surfaces
periodically to relay data via satellite.
(Illustration by Jack Cook, Woods Hole Oceanographic Institution)