The northwest slope of Kohala volcano has few large stream vallies cut into it compared to the other parts of the volcano (see the following images). This is due to the "rain shadow" effect, with the trade winds bringing most rainfall to the northeastern side of the volcano. The port of Kawaihae is in the foreground. Photo by Scott Rowland.
Flying from west to east along the north coast of Kohala volcano, we see a large number of deeply dissected stream valleys cut into the flanks of the volcano. Photos by Scott Rowland.
Viewed from off-shore, the numerous deeply eroded valleys on the north shore of Kohala volcano are spectacular! In this rare almost cloud- free scene, we can see Waipio Valley at left and Waimanu Valley at right. At the back of the valleys, these are more than 800 meters deep. Notice that even the more gentle slopes of the volcano in between Waipio and Waimanu is starting to be be eroded.
The northern side of Kohala volcano, which is the oldest volcano on the Big Island, is deeply eroded by numerous large river valleys. Here we see the upper parts of Waimanu Valley (bottom center) and Waipio Valley (left).
This is another view of the northern slopes of Kohala volcano. The upper part of Honokane Valley is at bottom left. Notice the numerous small volcanic cones in the middle distance, and Kawaihae Bay at top right.
Copyright by P. Mouginis-Mark