PLANETARY ORIGINS AND CORRELATIONS WITH MOLTEN ROCK

2018-04-11 14:13:56 Cedric Dent 기자

A lay understanding of what molten rock is doesn’t really suggest that it’s as important as it is, but it’s very significant to origin studies in the broad sense of the phrase, as evidenced by two very recently published studies that illustrate as much. The significance of molten rock can best be exemplified in areas like oceanography, geology and astronomy, and this is because it’s one of the main things scientists look at when they’re trying to study the evolution of not animals necessarily but the world on which they live as well as other worlds around ours. We study other planets in manners somewhat similar to how we study earth, and this can very often involve molten rock for a variety of reasons.

One oceanographer, Christopher Kincaid, is held in very high esteem in the global scientific community for his work at the University of Rhode Island’s Graduate School of Oceanography. His most notable research over the years has dealt with Earth’s fluid circulation between the planet’s interior and the coastal ocean because it’s given us an excellent, very comprehensive idea of how fluids drain on earth. At the university, Kincaid even has his own (per se) Viscous Geophysical Fluid Dynamics Laboratory on the university’s Bay Campus, and that’s where he built the Ridge Zone Replicator with the invaluable help of a graduate student named Loes van Dam.

The Ridge Zone Replicator is a new apparatus for which van Dam’s newly published study actually utilized in such a way that it best demonstrates the most insightful uses. Even though molten rock is ideal for the scientific study of the earth in the most general sense, it’s become increasingly difficult to obtain, which is why van Dam decided to use mass amounts of corn syrup to simulate the flows of molten rock. The way earth’s molten rock flows beneath ocean ridges is what gives oceanographers such valuable insight into how Earth evolved as a planet over time, and in its paucity, if a substitute can be drummed up, then that insight isn’t as scarce.

“Corn syrup behaves similarly to molten rock,” according to van Dam. “Its flow in laboratory minutes resembles molten rock’s flow over millions of years in the real world.” As such, the 23-year-old grad student helped Kincaid build the RZR last summer in order to run experiments on tectonic plates. The RZR holds about 165 gallons of corn syrup or three full barrels’ worth. These plates, of course, are actually simulated to scale, and van Dam made those out of six polyurethane belts, which are all motor-driven. We’re talking about the kind of motor that can, indeed, pull a car.

The RZR moves the corn syrup at the turn of a knob in a way that corresponds with whatever characteristics Kincaid and van Dam want it to mimic relative to mid-ocean ridges that they model for accuracy. “We find interesting features in the flow patterns, depending on the speed and directions of the plate motion, and the different ridge geometries,” van Dam explains. “The flows from linear ridge sections look much more simple than the flows from more jagged ridge sections.” Kincaid adds that, as far as he knows, van Dam’s is the first-in-kind study in that it simulates every likely syrup response to the entire tectonic plate range of motion seen at mid-ocean ridges. Thus far, scientists have found it difficult to render this kind of simulation, relying primarily on computer sims that inadequately represent ridge movement.

“Our research on these flows tells us something about volcanic activity at mid-ocean ridges and the way the seafloor looks in these places. In the process, we’re learning about how the Earth evolves,” van Dam adds, and without any corn syrup at all, which should come as no surprise, other researchers are learning groundbreaking things about how Earth’s moon likely formed, too. Shattering old suppositions, the new theory is that it formed from a cloud of molten rock, possibly prior to the formation of Earth itself.

The groundbreaking moon theory comes from a research team at the University of California, Davis. They call this molten rock cloud a synestia, which is just a ring of debris comprised in large part of molten rock, which comes together after a protoplanet collision. In the context of specifically our moon, this theory posits that said collision would have to have been not only massive but super early in the history of our solar system. The team theorizes that the moon formed within, perhaps, only a few dozen years of the collision while the synestia was continually cooling and shrinking, and the Earth would’ve come to be a whole millennium later.

“The new work explains features of the moon that are hard to resolve with current ideas,” according to Sarah Stewart, a co-author on the published study and an Earth and Planetary Sciences professor at UCD. “The moon is chemically almost the same as the Earth, but with some differences. This is the first model that can match the pattern of the moon’s composition,” which is the other groundbreaking part of the study in addition to the theory itself, which is something of a head-scratcher. A synestia, mind you, is hypothetical in and of itself; Stewart came up with that concept in 2017 with the help of Simon Lock, a graduate student from Harvard University and a co-author on the study.

These are essentially examples from two very recent studies that show how integral molten rock is to, at the very least, the studies of origins of our world and its moon. Given the chemical likeness between Earth and its moon, there’s bound to be a lot of overlap when determining why molten rock is significant to the origin studies of both.

[researchpaper 리서치페이퍼=Cedric Dent 기자]

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