Seafloor spreading is thought to proceed as a succession of ‘quantum’ events of extension, involving earthquakes and [magma] intrusions.” Related Story Underwater Lightning Still Baffles ScientistsBy “quantum,” Royer meant that these events are separate and distinct from each other. “Spreading segments undergo decades of quiescent stretching as abutting transforms accrue displacements by frequent slip events,” Royer said. “The stresses that build up in the MOR segment are released during quantum events of seafloor spreading that involve both [magma intrusion] and fault slip. This may be the primary mechanism by which MOR normal faults accumulate displacement, potentially explaining their seismic moment deficit.”