The Heirtzler fracture zone is an undersea fracture zone located south of New Zealand, near Antarctica, that has been estimated to have been a propagator region of the PacificâÂÂAntarctic Ridge for 5âÂÂ6 million years.
The presumed seismically and tectonically active portion of this fracture zone is known as the Heirtzler transform fault and divides a portion of the Pacific-Antarctic Ridge where spreading rates increase towards its axial north from /year over a distance of . The Heirtzler transform fault portion has areas of gravity highs, and as well as its larger propagating region, it has to the southeast a smaller Pacific-Antarctic Ridge propagator that may have started about one million years ago, with both associated with clockwise changes in spreading direction.
The feature was named for James R. Heirtzler, a geophysicist who was a pioneer in geomagnetics studies. The name was proposed by the LamontâÂÂDoherty Geological Observatory (now the LamontâÂÂDoherty Earth Observatory), and was approved by the Advisory Committee on Undersea Features in 1993.