Geology by the millions

LIHUE — Kauai’s landscape has quite a story to tell.

The estimated 5-million-year-old island is slowly sinking and drifting 3.5 inches per year toward Japan, so it’s always changing.

To look at its past, a young Kauai looked more like the volcanic, higher elevated Big Island. Millions of years from now, it will resemble the atolls of Midway and Kure, which are sunken islands where coral reefs are the only things breaking the sea’s surface.

“That’s Kauai’s future,” said Chuck Blay, looking ahead about 10 million years down the line when the island is under water. “There won’t be any lava rocks above sea level.”

The geologist Blay is presenting a talk on the history of Kauai as explained though its landscape.

Mahaulepu, on the island’s south side, has preserved the longest documented range of geologic history to be found anywhere in the state. Lava rocks date 5 million years old and sand dunes are 400,000 years old. The islands are gigantic volcanic mountains and the waters around Kauai drop 18,000 feet, meaning “these are the largest mountains on Earth, no question.”

“To me it’s like a time machine demonstrating 30 million years of geological evolution,” Blay said about the islands.

Learning about Kauai’s geological history can also lend a new perspective on what people consider history in general. For a lot of people, it can be hard to grasp geological years compared to the thousands of years modern humans have been around.

On Kauai, they’ve been here for 1,200 years, Blay said. And when they were introduced there weren’t any land mammals or land reptiles, only plants, birds and insects.

“What is history and how do we define it? Some people think history is when we started writing things down. What about history before history?” Blay said. “I am going to use the island as an example on how we determine time, how we deal with time.”

The free lecture, presented by The Kauai Historical Society, is at 6:30 p.m. Jan. 22 at the main hall of Island School, 3-1875 Kaumualii Highway in Lihue.



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