Composition: Kohala lava flows
Explanation: Waipi'o Valley is a large canyon cut by deep erosion and deepened by sea level changes. Rises in sea level have resulted in the current aggradation. Landslide scarps surrounding the valley are due to the effects of landslides on the steep walls of the valley. You can see deep landslide scars cut into the valley walls in the picture on the right.
Offshore Landslides
Explanation: As pressure continually builds up under the Hawaiian Islands large blocks of land begin to flow into the sea. As these blocks move large earthquakes can occur which can result in enormous waves and the movement of mass amounts of sediment. According to U.S.G.S. marine scientists 15 landslide deposits surround the Hawaiian islands. Since these mass movements of land do not occur frequently residents and tourists do not understand the danger these landslides can bring. They dramatically change the topography of the islands and surrounding sea while large areas of land are dumped into the sea.
"Recently, much attention has been paid to the instability of the Big Island and its catastrophic slides into the sea. Giant tsunami, hundreds of meters high, are visualized as lethal byproducts of these giant submarine landslides. Interpretations of seafloor topography suggest that submarine landslides have occurred repeatedly in the past around all of Hawaii's major islands. One scientifically controversial interpretation is that a giant tsunami 330 m (1,000 ft) high, triggered by a submarine landslide off the Kona coast, swept across Lana`i about 100,000 years ago.
There has been much media attention regarding these landslides and tsunamis. There was a report last March of Kilauea's south flank moving 7.1 cm/sec (2.8 inches/second) generated nationwide interest but exaggerated the rate by 22.4 million times; the actual maximum rate is about 10 cm/year (4 inches/year).
Before visiting Hawaii it is important to understand the dangers of the islands. Loose ground along trails and roadside stops can result in small landslides down the steep slopes of the volcanoes. It is important to travel with a group of experienced hikers and bring the appropriate supplies needed along the treacherous terrain.
Information from this page has come from the U.S.G.S. site
Links to papers on the topic:
Hydroacustic detection of submarine landslides on Kilauea volcano
Tsunami modeling from submarine landslides
Albion College geology students and professors created these web pages as a follow-up to our March 2003 Geology 210 Regional Field Geology class trip to Hawaii. The images, except where noted, are a product of our trip. We make them available for non-profit, educational uses. As a condition of use, we request that you inform the page author or Thom Wilch. Thank You.
Waipi'o Valley on the island of Hawaii
Photo by: Emily Ernsberger.
This picture is a Pali on Chain of Craters Road. It is generally showing a fault block (we are standing on it) that will possibly be part of a future submarine landslide.
Photo by: Thom Wilch
This is a picture from an article on submarine landslides and flank deformation on Kilauea. Click here for link to web site.
Photo from: http://www.geophysics.rice.edu