One of the best places for tourists and locals to go snorkling is Hanauma Bay. This is a State Park, and in recent years a lot of hard work has gone into making the Bay even cleaner and more attractive for both the visitors and the fish. Hanauma Bay is also fascinating for anyone who wants to walk along the shoreline for an hour or so. Here we see some of the attractions!
This is a view of Koko Crater, seen from the southern rim of Hanauma Bay. Notice the prominent erosional valleys on the flanks of Koko Crater. These indicate that the material from which this cone is constructed is easily eroded. As we will see at the coral inclusion image, this material is unconsolidated ash formed during violent steam explosions when the eruptions took place in shallow water.
The inner portion of Hanauma Bay is great for swimming and saying hello to the hundreds of colorful fish that frequent the Bay. Here we see a portion of the reef where the swimming is safe and gives both novices and experts a great chance to come face-to-face with the fish.
Walking along the coastline on the sides of Hanauma Bay one finds a feature called a "wave-cut platform", which is the flat layer of rock seen here. This platform is believed to have been formed by salt water protecting the loose rock that is near water level, while the crashing waves have eroded the less stable rock above the water line.
From here you can continue on to Stop 4 on the ground.
Return to Southeast Oahu Virtual Field Trip
Author: Peter Mouginis-Mark
Copyright by P. Mouginis-Mark
Curator: Lori Glaze