Oahu Dissolving? Researchers Say Island Erosion Increasing

Researchers studying the impact of erosion on the Hawaiian Islands have found that Oahu is eroding at a faster rate than the other islands with the majority of the erosion occurring in non-traditional ways.

Researchers from Brigham Young University in Utah spent two months trying to uncover the rate of erosion of the popular vacation destination.

"We tried to figure out how fast the island is going away and what the influence of climate is on that rate," Steve Nelson, a Brigham Young University geologist, wrote in a press release. "More material is dissolving from those islands than what is being carried off through erosion."

Nelson and his team found varying levels of erosion depending on where they recovered their samples given that precipitation on the island varies widely. The team also discovered that areas with large amounts of precipitation, which led to an increase in groundwater, increased the rate of erosion by several factors.

The researchers measured the amount of solids dissolved in both surface and groundwater from 45 streams and 30 springs and wells located throughout the island.

They found that groundwater was able to hold between three and 12 times the amount of dissolved materials compared to the amount of dissolved solids that are contained in water runoff.

This led researchers to find that underground springs and aquifers were responsible for eroding most of the island from the inside, rather than water runoff eroding the surface of the island.

"All of the Hawaiian Islands are made of just one kind of rock," Nelson said. "The weathering rates are variable, too, because rainfall is so variable, so it's a great natural laboratory."

Oahu, along with the other Hawaiian Island are located over a ocean hot spot, an open vent on the ocean floor that allowed lava to build up and eventually create the islands seen today. While researchers admit that Oahu is eroding at a fast rate, geologically speaking, it will still take millions of years before the islands will once again be overtaken by the ocean.