How Hawaii’s ‘necklace’ developed a bump in the middleApril 4th, 2009 - 2:04 pm ICT by ANI
Berlin, April 4 (ANI): A new research has suggested that a sharp bend in the middle of the Hawaii ‘necklace’ of islands is a result of a rapid drift of the region’s ‘hotspot’ in a southward direction between 80 and 40 million years ago before it came to a complete halt.
More than 80 undersea volcanoes and a multitude of islands are dotted along the Hawaii-Emperor seamount chain like pearls on a necklace.
A sharp bend in the middle is the only blemish.
This characteristic bend in the trail of the 5000-kilometer long Hawaii-Emperor seamount chain is one of the most striking topographical features of the earth, and is an identifying feature in representations of the Pacific Ocean floor.
The long-standing explanation for this distinctive feature was a change in direction of the Pacific oceanic plate in its migration over a stationary hotspot - an apparently unmoving volcano deep within the earth.
According to the results of an international research group, of which LMU Munich geophysicist Professor Hans-Peter Bunge was a member, however, the hotspot responsible for the Hawaii-Emperor seamount chain was not fixed.
Rather, it had been drifting quite distinctly southward.
Nearly 50 million years ago, it finally came to rest while the Pacific plate steadily pushed on, the combination of which resulted in the prominent bend.
Recent investigations also suggest that hotspots are less stationary than so far assumed.
An international research group, of which Professor Hans-Peter Bunge of the LMU Munich Department of Earth and Environmental Sciences was a member, took a closer look at certain evidence pointing towards substantial inherent motion of the underground volcanoes, and has now confirmed this evidence.
“Paleomagnetic observations suggest that the bend in the Hawaii-Emperor chain is not the result of a change in the relative motion of the Pacific plate,” Bunge states.
“On the contrary, it seems the hotspot had been drifting rapidly in a southward direction between 80 and 40 million years ago before it came to a complete halt,” he added.
If the trail of the Hawaiian hotspot is corrected to include this drift, the result implies a largely constant movement of the Pacific plate over the last 80 million years.
The bend ultimately came about as the hotspot started to slow down.
The driving force behind the migration of the hotspot is the circulation of material under the surface of our planet.
“The earth’s interior is in constant motion. Over geological timescales, this motion compares to the weather patterns in our atmosphere. These patterns can easily lead to a change in position of hotspots,” said Bunge. (ANI)
Tags: 50 million, blemish, bunge, change in direction, closer look, distinctive feature, emperor seamount chain, environmental sciences, geophysicist, hotspot, hotspots, international research group, lmu munich, million years, oceanic plate, pacific ocean floor, relative motion, sharp bend, topographical features, Undersea volcanoes