Between 250.000 and 300.000 years ago the Kohala volcano experienced a truly massive landslide in which a part of the volcano fell into the ocean.
This landslide is responsible for the now famous sea cliffs on the windward Kohala shoreline but also triggered a giant tsunami that left marine deposits multiple 100 ft high on the other islands. Remnants from this landslide can still be found under water 81 miles (130 km) from the current coastline.