Scientists Say Earth Is Undergoing True Polar Wander, Bright Comet Streaking By Saturn Now, Will Be Visible Nov. 2013
October 2, 2012 – EARTH - True polar wander is a geophysical theory, a way of thinking about Earth processes that might happen and that these scientists believe do happen. The theory suggests that if an object of sufficient weight on Earth – for example, a supersized volcano or other weighty land mass – formed far from Earth’s equator, the force of Earth’s rotation would gradually pull the object away from the axis around which Earth spins. A supersized volcano far from Earth’s equator would create an imbalance, in other words. As explained at Princeton.edu: If the volcanoes, land and other masses that exist within the spinning Earth ever became sufficiently imbalanced, the planet would tilt and rotate itself until this extra weight was relocated to a point along the equator. That’s the theory of true polar wander. It would cause a movement of Earth’s land masses, but for a different reason than the reason the continents drift in the theory of plate tectonics (formerly called “continental drift”). In the theory of plate tectonics, the continents drift because Earth’s the layer of Earth underlying our planet’s crust (called the mantle) is convective. That is, it circulates, slowly – like water about to boil. In true polar wander, on the other hand, a similar-seeming movement of land masses on Earth’s crust happens in order to correct an imbalance of weight with respect to Earth’s spin. Scientists’ understanding of true polar wander overlaps with their understanding of plate tectonics in various ways. That’s understandable, since it’s all the same Earth. Scientists delving into true polar wander want to know when, in which direction, and at what rate the Earth’s solid exterior might be rotating due to true polar wander. To sort it out, they say, you would need a stable frame of reference to which observations of relative motion might be compared. Doubrovine and his team say they found one: volcanic hotspots. Oceanic hotspots form an island chain. As land plates drift, a successive of volcanoes form over the hotspot. In geology, hotspots are volcanic regions fed by Earth’s underlying mantle. For example, the Hawaiian Islands are believed to have formed over a hotspot in the mantle. The hotspot created a volcano, but then – as that land plate drifted over time, as described by the theory of plate tectonics – the volcano drifted, too, and was eventually cut off from the hotspot. Gradually, another volcano begins to form over the hotspot, right next to the first one. And then it moves on … and another one forms … and so on … and so on. Earth’s crust produces first one, then another volcano over the hotspot until a long chain of volcanoes forms, such as in Hawaii. Hotspots have long been used to understand the motion of tectonic plates. Doubrovine and colleagues went a step further in order to understand true polar wander. Instead of treating the hot spots as static – frozen in place at one spot above Earth’s mantle – their computer model let the hotspots’ positions drift slowly. According to these scientists, this drifting is what produced a model of a stable reference frame, which in turn let them draw conclusions about true polar wander. They say their model does a good job of matching observations of real hotspot tracks on Earth – the path drawn by each hotspot’s island chain – which gives them confidence their results about true polar wander are accurate.
46 Pilot Whales Stranded in Indonesia, 3 Alive
Indonesian officials say 46 pilot whales have beached themselves on a southern island. All but three have died.
Pramudya Harzani from the nonprofit Jakarta Animal Aid Network activists and local authorities were still trying to rescue the three surviving whales on Tuesday but they kept swimming back to shore.
He says he whales washed ashore late Monday in Raijua beach on Sabu, a small islet between Timor and Sumba islands in southern Indonesia.
District chief Gidon Bilibora says meat from the dead whales has been taken by locals for food, a common practice in the area.
Scientists believe the whales follow a group leader to shore when it gets sick, stranding them. Harzani says the stranding may have been partially caused by rapidly receding tides due to seasonal monsoons.
Brightest comet ever could make spectacular appearance 2013-2014
October 2, 2012 – SPACE – If astronomers’ early predictions hold true, the holidays next year may hold a glowing gift for stargazers—a super bright comet, just discovered streaking near Saturn. Even with powerful telescopes, comet 2012 S1 (ISON) is now just a faint glow in the constellation Cancer. But the ball of ice and rocks might become visible to the naked eye for a few months in late 2013 and early 2014—perhaps outshining the moon, astronomers say. The comet is already remarkably bright, given how far it is from the sun, astronomer Raminder Singh Samra said. What’s more, 2012 S1 seems to be following the path of the Great Comet of 1680, considered one of the most spectacular ever seen from Earth. “If it lives up to expectations, this comet may be one of the brightest in history,” said Samra, of the H.R. MacMillan Space Centre in Vancouver, Canada. So what makes a comet a showstopper? A lot depends on how much gas and dust is blasted off the central core of ice and rocks. The bigger the resulting cloud and tail, the more reflective the body may be. Because 2012 S1 appears to be fairly large—possibly approaching two miles (three kilometers) wide—and will fly very close to the sun, astronomers have calculated that the comet may shine brighter, though not bigger, than the full moon in the evening sky. First spotted late last week by Russian astronomers Artyom Novichonok and Vitali Nevski of the International Scientific Optical Network (ISON), comet 2012 S1 was confirmed by the International Astronomical Union on Monday. But while we know what 2012 S1 is, it’s still unclear where it came from. Its orbit suggests the comet may be a runaway from the Oort cloud, where billions of comets orbit about a hundred thousand times farther from the sun than Earth is. Right now, 2012 S1 appears to be about 615 million miles (990 million kilometers) from Earth, between the orbits of Saturn and Jupiter, astronomers say. As the sun’s gravity pulls the comet closer, it should pass about 6.2 million miles (10 million kilometers) from Mars—possibly a unique photo opportunity for NASA’s new Curiosity rover. Current orbital predictions indicate the comet will look brightest to us in the weeks just after its closest approach to the sun, on November 28, 2013—if 2012 S1 survives the experience. As the comet comes within about 1.2 million miles (2 million kilometers) of the sun, the star’s intense heat and gravity could cause the ice and rubble to break apart, scotching the sky show. “While some predictions suggest it may become as bright as the full moon and even visible during the day, one should be cautious when predicting how exciting a comet may get,” Samra said. “Some comets have been notorious for creating a buzz but failing to put on a dazzling display,” he said. “Only time will tell.”
Large explosion and CME on the farside of the Sun
September 28, 2012 – SPACE – A sunspot on the farside of the sun exploded on Sept. 27th, sparking a bright flare of extreme ultraviolet radiation and hurling a massive CME into space. Although the explosion occurred on the other side of the sun, it was visible by NASA’s 3-D app on cell phones around Earth.
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