On the island of Mauna Kea in Hawaii, boulders that were deposited by an ancient glacier were found and have provided evidence toward global change. Particularly a slowdown of the North Atlantic Ocean current system which scientists believe to be a major concern of climate change. A new study has found geochemical clues near the summit of Mauna Kea that shows ancient glacier formation, influence of the most recent ice age, major storms in Hawaii, and impacts of a distant climatic event that changed much of the world.
Mauna Kea had a large glacial ice cap of about 70 kilometers until about 14,500 years ago, but now it has all disappeared. At 13,803 feet, Mauna Kea, is in a way the tallest mountain in the world because it rises 30,000 feet from the sea floor. It once feature a large glacier on its peak at the height of the last ice age thousands of years ago. As the ice age ended, and the global climate changed , the glacier slowly melted away. However, the new research found that the glacier began to re-advance to almost its ice-age size. The findings were supported by the measurements of an isotope of helium being produced in the boulders left by the glaciers years ago. The amount of this helium isotope reveals when the boulders were finally uncovered by ice and exposed to the atmosphere.
That is really cool to hear about the glaciers atop Mauna Kea. I have never really thought about glaciers being in Hawaii because it is, after all, a tropical island. I wonder where else glaciers formed that we do not know about.