West Molokaûi Volcano, sometimes called Mauna Loa for the census-designated place, is an extinct shield volcano comprising the western half of Molokaûi island in the U.S. state of Hawaii.
It was formed in two volcanic phases during the Pleistocene epoch of the Quaternary period in the Cenozoic Era.
The first formed the broad tholeiitic shield volcano of West Molokaûi that ended 1.89 million years ago. The second volcanic phase produced postshield alkalic volcanics 1.76 million years ago. There is no evidence for a rejuvenated phase of the West Molokaûi Volcano, whilst the East Molokaûi Volcano does.
West Molokaûi overlaps the western flank of East Molokaûi Volcano, a much larger shield volcano comprising two-thirds of Molokaûi. Two distinct rift zones are present on the western flank of the volcano, forming a v shape. A third rift zone possibly extended eastward towards the modern day East Molokaûi Volcano. A collapse occurred around (uncertain) years ago on the eastern/north eastern flank of the volcano and lava flows from East Molokaûi had filled in the open space, connecting the two volcanoes above surface (also known as the Molokaûi Saddle). The cliffs of the eastern side of West Molokaûi is the only remaining evidence for this land slip. Keep note that the West Molokaûi slip is completely separate from the much larger slip of the East Molokaûi Volcano.