Studies of past climate change indicate that the AMOC has slowed a number of times, in surprisingly short periods, causing substantial cooling of Europe. Because of that, the potential future decline of the current is of considerable interest.
But scientists have found that the AMOC does more than just keep northern Europe habitable. Its effects can extend far beyond that.
"The new data from Mauna Kea, along with other findings from geological archives preserved in oceans and lakes in many other areas, show that the decline of the AMOC basically caused climate changes all over the world," Clark said. "These connections are pretty remarkable, a current pattern in the North Atlantic affecting glacier development thousands of miles away in the Hawaiian Islands.
"The global impact of the AMOC changes," Clark added, "was just massive."
The formation, size and movement of glaciers can provide valuable data, he said, because these characteristics reflect current and historic changes in temperature, precipitation or both.
The study concludes that the growth of the Mauna Kea glacier caused by the AMOC current changes was a result of both colder conditions and a huge increase of precipitation on Mauna Kea triple that of the present that scientists believe may have been caused by more frequent cyclonic storm events hitting the Hawaiian Islands from the north.
The findings were supported by measurements of an isotope of helium being produced in boulders left by the Mauna Kea glacier thousands of years ago. The amount of this helium isotope reveals when the boulders were finally uncovered by ice and exposed to the atmosphere.
The deposits containing the boulders are the only record of glaciation in the north
|Contact: Peter Clark|
Oregon State University