![Maui political map](https://wp-media.patheos.com/blogs/sites/186/2017/07/Maui_region_map_EN-1024x712.png)
The basic geology of Maui is pretty obvious: An older volcano to west-northwest, now much eroded, and a new and larger volcano to the south-southeast, connected by a plain formed by the confluence of their lava flows.
The larger, younger volcano to the east-southeast, Haleakalā (“house of the sun”), rises to a height of 10,023 feet (3,055 meters) above sea level. More dramatically, perhaps, it measures five miles (eight kilometers) from seafloor to summit, making it one of the world’s tallest mountains.
![The Hawaiian Islands -- geology](https://wp-media.patheos.com/blogs/sites/186/2017/07/Bathymetry_image_of_the_Hawaiian_archipelago-1024x791.png)
If the sea were a bit lower, or if the other connecting volcanic plains were a bit higher, Maui and Lana’i and Moloka’i and Kaho’olawe (and perhaps even Oahu_ would all be one single unified island. Omitting Oahu, geologists call that unit or assemblage Maui Nui, or “greater Maui.” In fact, just 20,000 years ago — not far back, geologically speaking — they were so unified.
Posted from Ka’anapali, Maui, Hawai’i