By Nehemiah Putnam
Active or Passive?
The Hawaiian islands are located on a "hot spot" on the Pacific Plate. Because this island is located on the Pacific Plate, there a vast amount of plate activity, causing this to have active beaches.
Primary or Secondary?
The Punalu'u Beach is a Secondary beach. The Hawaiian islands have been active for at least 70 million years. The beaches on the island are very old, causing this beach to be secondary. This beach was formed by volcanic activity from the Mauna Loa and the Kilauea volcanoes spilled over into the water and quickly cooling, breaking the granules down, giving it the black sand.
The Black Volcanic Sand
The sand color of Punalu'u Beach is black, due to volcanic activity (ash and lava spilling over) and is made up of basalt, andesite, and volcanic glass
Origin and Structure
Punalu'u Beach is the lagest black sand beach and the name literally means, "diving spring" when Hawaiians during the drought, would dive underneath to obtain fresh water. The waters of this beach are very choppy and the land is very rugged.