Scientists reveal that the rotation of Earth's core holds a clue to understanding global sea-level rise.© University of Alberta
Scientists are studying past changes in sea level to make accurate future predictions of this consequence of climate change, and they're looking down to Earth's core to do so.
"In order to fully understand the sea-level change that has occurred in the past century, we need to understand the dynamics of the flow in Earth's core," says
Mathieu Dumberry, a professor in the
Department of Physics at the University of Alberta.
The connection is through the change in the speed of Earth's rotation. Meltwater from glaciers not only causes sea levels to rise, but also shifts mass from the pole to the equator, which slows down the rotation. (Picture the Earth as a spinning figure skater. The skater moves his or her arms in to spin more quickly or out to slow down.) The gravity pull from the Moon also contributes to the slowdown, acting a little like a lever brake. However, says Dumberry, the combination of these effects is not enough to explain the observations of the slowing down of Earth's rotation: a contribution from Earth's core must be added.
One of only a few people in the world investigating changes in Earth's rotation, Dumberry contributed his expertise on Earth's core - mantle coupling to the study.
"Over the past 3,000 years, the core of the Earth has been speeding up a little, and the mantle-crust on which we stand is slowing down." As a consequence of Earth rotating more slowly, the length of our days is slowly increasing. In fact, a century from now, the length of a day will have increased by 1.7 milliseconds. This may not seem like much, but Dumberry notes that this is a cumulative effect that adds up over time.
Based on their work reconciling these discrepancies, the scientists involved in the study are confident in predicting sea levels to the end of the 21
st century. "This can help to better prepare coastal towns, for example, to cope with climate change," says Dumberry. "We're talking billions of dollars of infrastructure here." Dumberry notes that this study serves as a stimulus for more work to continue investigating the deep interior of our planet.
The findings, "Reconciling past changes in Earth's rotation with 20
th century global sea-level rise: Resolving Munk's enigma," were published in the Dec. 11 issue of the journal
Science Advances.
If earth rotation can slow from sea-level rise, does that also imply that sea-level can rise due to slowing of earth rotation?
It's interesting that yesterday afternoon I resolved to do some research on sea-level rising. Such is often the case for me, that an article on Sott and often various articles on on multiple news feeds will show up within a day and having to do with a subject that has my attention. I tend to pay closer attention when it happens.
I had been talking with my mother-in-law, who not says she "believes" in climate change. I wasn't interested in discussing climate change, only in her use of the word "believe." Belief has nothing to do with science, and climate change is supposed to be proven by science, so why is there any need for belief? Of course, being typically educated and ignorant, she was unable to move away from her "belief" in climate change, and to the extent that she was unable to even see that I wasn't asking about climate change. I wanted to know why she believes in "belief." But I digress.
First, anyone have an answer to the question about slowing rotation possibly causing sea-level rise?
Second, anyone experience synchronicity with Sott or other news feeds regarding topics of interest (and not just passing interest, but when a specific intention is made to follow up on a topic)?