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Structure of the Earth

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*****Country locations prior to continental drift 3D animation. *****Continental drift / Break up if Pangaea supercontinent-breakup-drove-evolution-2407903317. *****Continental drift / Watch the supercontinent of Pangea break up into our modern continents. (Gif by @LazaroGamio for @Axios.) Here’s what the world have looked like about 300 million years ago but with today’s political borders. (Pangea Politica, Massimo Pietrobon) Saturn's icy, ocean-bearing moon Enceladus may have tipped over in the distant past due to a collision w/ asteroid. Untitled. Credit: K.

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Cantner, AGI. By Mary Caperton Morton The basic story of Earth’s formation is familiar to most anyone who has taken a geology course: About 4.6 billion years ago, Earth formed when a rocky nucleus accreted dust and debris left over from the formation of our sun. At first, Earth did not look like a place that would eventually support life. But early on, the young, red-hot planet began laying the foundation for becoming a mature, hospitable “blue” planet. The nature of plate tectonics means that the process masks its own origin story: As new oceanic crust is formed at spreading centers, old crust is destroyed in subduction zones. “There’s a lot we don’t know about how these plate tectonics systems work in the present day,” says Leigh Royden, a geophysicist at MIT.

But even if we had a perfect understanding of modern plate tectonics, that wouldn’t necessarily tell us everything about how the process got started, says Taras Gerya, a geodynamicist at ETH Zürich in Switzerland. *****Time flies: Insect fossils in amber shed light on India's geological history. A new species of fungus gnat in Indian amber closely resembles its fossil relatives from Europe, disproving the concept of a strongly isolated Indian subcontinent.

*****Time flies: Insect fossils in amber shed light on India's geological history

Researchers have identified three new species of insects encased in Cambay amber dating from over 54 million years ago. In a new study published by PeerJ, researchers describe the new species of fungus gnats, which provide further clues to understanding India’s past diversity and geological history. The most interesting finding from the discovery of these new gnat species is related to India´s plate tectonic history: Palaeognoriste orientale in Cambay amber belongs to a group that has previously been reported from slightly younger Baltic amber only. Theconversation. If you could travel back in time 41,000 years to the last ice age, your compass would point south instead of north.

theconversation

That’s because for a period of a few hundred years, the Earth’s magnetic field was reversed. These reversals have happpened repeatedly over the planet’s history, sometimes lasting hundreds of thousands of years. We know this from the way it affects the formation of magnetic minerals, that we can now study on the Earth’s surface. Several ideas exist to explain why magnetic field reversals happen. One of these just became more plausible. *****Earth probably began with a solid shell (Earth's crust) .@LeaneEoin New projection of future continental drift. ¿Qué pasaría si te tiraras por un agujero que atravesara la Tierra? Via @MetaBallStudios. ***** Is Britain on the move? - Ordnance Survey Blog. OS Maps uses GPS to position you Australia has recently announced a 1.8m shift in its mapping coordinates, to compensate for the country’s 7.5cm shift north each year.

***** Is Britain on the move? - Ordnance Survey Blog

Inevitably the question is why, and could the same thing happen here? In Australia, the shift is to take into account the growing difference between maps (and the coordinate reference system they’re based on) and the system used by satellite positioning (GPS). It’s a fact that the world is constantly shifting on tectonic plates, but maps (and their users) like fixed coordinates that don’t change.

Before GPS, this was simple to achieve as most positioning and mapping was created from fixed ground points in a coordinate reference system tuned to a particular country. GPS is a global system and requires a coordinate reference system that has a good average fit to the whole Earth, and also has to change to keep up with the shifting of tectonic plates – it is effectively 4D (3D + time). OS Net locations across Britain. *****Why Mars could soon have rings like Saturn.

Early Mars may have had rings like Saturn, and might have them again, according to a new model.

*****Why Mars could soon have rings like Saturn

The research suggests that debris, pushed into space from an asteroid or other body, slammed into the red planet around 4.3 billion years ago and alternates between becoming a planetary ring and clumping up to form a moon. A theory exists that Mars’ large North Polar Basin or Borealis Basin, which covers about 40 percent of the planet in its northern hemisphere, results from that impact, sending debris into space. “That large impact would have blasted enough material off the surface of Mars to form a ring,” says Andrew Hesselbrock, a doctoral student in physics and astronomy at Purdue University. Stunningly beautiful jellyfish found while exploring The Enigma Seamount at a depth of ~3,700 meters.

Scientists still can't decide how water got to Earth. The Earth has been the blue planet for as many as 3.8 billion years.

Scientists still can't decide how water got to Earth

Ancient sedimentary rock deposits and lava that cooled into characteristic pillow shapes provide irrefutable evidence that liquid water has existed at the Earth’s surface for at least this long. But given how many barren rocks there are in the galaxy, Earth’s abundant oceans raise the question of where all that water came from. Geoscientists continue to debate two competing theories. From Pangaea to the present. Watch the continents evolve: 250 million years from Pangea to the present, ht: @amazingmap. *****Enceladus: Another smoking gun in the search for life in Enceladus’ ocean. This illustration shows Cassini diving through the Enceladus plume in 2015.Credits: NASA/JPL-Caltech Today, NASA-funded scientists announced a major new step in the search for life on Enceladus, Saturn’s sixth-largest moon, thanks to new data collected by the NASA/ESA Cassini mission.

*****Enceladus: Another smoking gun in the search for life in Enceladus’ ocean

Enceladus has attracted a lot of interest because it has an active pole that spews jets of material into outer space. During its last flyby over that pole, an instrument on board the Cassini spacecraft detected the presence of a biomarker—molecular hydrogen. *****Enceladus: Life on another planet? Ever since studies started suggesting that chemical reactions between water and rock on Saturn’s moon Enceladus could provide enough energy in the water to feed microbial life, scientists have been searching for proof that the right sort of reactions really do occur.

*****Enceladus: Life on another planet?

And during its last dive through the icy plumes that Enceladus erupts into space in October 2015, the Cassini spacecraft has finally managed to find it – in the form of molecular hydrogen. The finding, published in Science, means the moon can now be considered highly likely to be suitable to host microbial life. If Pangea was today... *****These are the five major extinctions of planet Earth.

Plate tectonics cannot explain dynamics of Earth and crust formation more than three billion years ago. The current theory of continental drift provides a good model for understanding terrestrial processes through history.

Plate tectonics cannot explain dynamics of Earth and crust formation more than three billion years ago

However, while plate tectonics is able to successfully shed light on processes up to 3 billion years ago, the theory isn't sufficient in explaining the dynamics of Earth and crust formation before that point and through to the earliest formation of planet, some 4.6 billion years ago. This is the conclusion of Tomas Naæraa of the Nordic Center for Earth Evolution at the Natural History Museum of Denmark, a part of the University of Copenhagen. His new doctoral dissertation has just been published by the journal Nature.

*****Meteor showers from space. What am I looking at?

*****Meteor showers from space

Meteor showers on Earth are caused by streams of meteoroids hitting our atmosphere. These meteoroids are sand- and pebble-sized bits of rock that were once released from their parent comet. Some comets are no longer active and are now called asteroids. This visualization shows these meteoroid streams orbiting the Sun, some stretching to the outer regions of the solar system. Select the meteor shower in the menu to see the corresponding meteoroid stream in space. This visualization is developed and hosted by Ian Webster. How can I see a meteor shower? Meteor showers are best seen on certain dark and clear nights. Where should I go next? If you like these sorts of interactive visualizations, take a look at Ian Webster's other tools, including Pluto, ancient Earth, or asteroids!

***Meteor in aurora: Cool! Lucky catch. Bright enough that its hard to see #aurora RT @amsmeteors Aurora & Fireball over AK: 3/22 11:30pm. Earth has a new continent called 'Zealandia', study reveals. Geologists used to think Earth had six continents, but a new study adds a seventh: “Zealandia.” Recent satellite data and rock samples are behind the conclusion. New Zealand and New Caledonia are part of the new continent, which is about as big as greater India. The new continent could have economic and geopolitical implications. Kids are frequently taught that seven continents exist: Africa, Asia, Antarctica, Australia, Europe, North America, and South America.

Geologists, who look at the rocks (and tend to ignore the humans), group Europe and Asia into its own supercontinent — Eurasia — making for a total of six geologic continents. *****GPlates Portal: Visualisation of tectonics. 20 Things You Didn't Know About "Inner Earth" 1. In 1692 Edmond Halley (of comet fame) proposed that the Earth is hollow. Below the outer crust where we live, he pictured two concentric shells and a core about the size of Mercury, all floating in a luminous gas. *****Sea floor spreading and magnetic anomalies (kinaesthetic) with L6 Geols □ *****Geological time cartoon graphic: This fabulous Earth history graphic by Ray Troll is wonderful for teaching #FossilFriday #scicomm #geology.

These fossils are possibly the oldest known evidence for life on Earth. *****Earth's interior temperature 60 degrees hotter than previously thought, student accidentally finds. Posted Earth's interior temperature is about 60 degrees Celsius hotter than previously thought and could explain how tectonic plates move on Earth's surface, research by a 28-year-old United States PhD student has found. PhD student Emily Sarafian stumbled upon the discovery while researching the melting point of mantle rock — the layer between Earth's crust and its core. "While we did not necessarily set out to measure the mantle temperature, our experimental results on the melting point of mantle rock showed us the new mantle temperature," Ms Sarafian told ABC News. "In fact, mantle must be 60 degrees Celsius hotter than current estimates.

That's a very significant jump. " Life on Earth began earlier than thought - @BBCPallab gets close to some extremely old fossils. Blood Falls in #Antarctica are a sign of extraordinary microbial life deep below ground. Australian rocks suggest early Earth may not have had #plate #tectonics. Via @CosmosMagazine. Europe and Africa are so close geographically: here is the strait of Gibraltar, where they all but touch each other. What Does a Meteor Sound Like? - D-brief. (Credit: Cylonphoto/Shutterstock) When a meteor screams through our upper atmosphere, it’s a silent show for us here on the ground.

Potential new continent, "Zealandia", could shake up our understanding of land. Simulation of two planets colliding. How does ‘Zealandia’ affect our understanding of what a continent is? *****Earth has a new continent called 'Zealandia', study reveals. *****Meet Zealandia, the underwater continent that New Zealand sits on. Ancient jars found in Judea reveal Earth's magnetic field is fluctuating, not diminishing. What to expect when the Earth's magnetic field goes into reverse. Battling sexism and dissension, Marie Tharp changed how we understand the Earth. *****It's Alive! Algae Survive 16 Months Exposure To Space. *****Biscuit models of plate margins. Map of every known meteorite that has fallen on earth.

Ink blot impacts: Dark spots in this pic show recent impact craters that occurred between 2008 & 2014 on Mars. Why Numbers Matter [Episode 2: Do Maps Lie?] Twitter. Devastation detectives try to solve dinosaur disappearance. This is how the Magnus Effect works. Simulation of two planets colliding. An animated map of global wind and weather. *****Pressure: 8,145m deepest fish 8,800m pressure equivalent to 40 jumbo jets on your head #challengerdeep.

*****Pressure: An interactive journey to the bottom of the sea. Martian Mantle Models Pave the Way for NASA's InSight Lander. The #Moho is the boundary between the mantle and crust. #Ophiolites allow us to see this at the surface, seen here at the Lizard, #Cornwall. Heat from Earth’s core could be underlying force in plate tectonics. Twitterverse, anyone knows what has happened to the Paleomap Project or knows of any other GIS data source for shapefiles of Pangea & Co?

July 30, 1920: Marie Tharp, the Woman who discovered the Backbone of Earth - Scientific American Blog Network. A little bit of #WednesdayWisdom from Alfred Wegener, regarded as the father of #PlateTectonics. A good summary of what a geologist does! NASA's step by step plan for an asteroid impact. Read more. New candidate for 'missing element' in Earth's core. ***Walter Pitman and the Smoking Gun of Plate Tectonics. Pangaea map with modern political borders. Molten iron river discovered speeding beneath Russia and Canada. Iron 'jet stream' detected in Earth's outer core. NASA Is Unprepared to Defend Earth From Comets - The Atlantic. Construtive plate margins: Symmetrical and Asymmetrical Spreading. Plates - understanding the tectonic jigsaw pieces. - GEOetc. The Meeting That Gave Birth to the Idea of Global Tectonics. Nickel clue to 'dinosaur killer' asteroid. Japan Sends Long Electric Whip Into Orbit, To Tame Space Junk.

How deep the ocean really is. Rejoined continents [This Dynamic Earth, USGS] All The Meteorites That Have Been Seen Falling to Earth Since 2500 BC. Ancient Space Dust Washes Up in Rooftop Gutters - Seeker. Space dust from the dawn of our solar system has been collected from city rooftop gutters. Fireball over Siberia today, temporarily turned night to day. The Limits of Life Beneath Deep Sea Hydrothermal Vents - The Extremo Files : The Extremo Files. Ancient rocks hold evidence for life before oxygen.

*Technosphere (anthropocene): A planet's worth of human-made things has been weighed. History of Earth in the context of a football field. Awesome G-Force demonstration. Plate Boundaries and Natural Hazards. Born today 1922: Stanley Runcorn. Discovered Earth's magnetic reversals. This was key to plate tectonic discovery. Jupiter shepherding the asteroid belt, preventing them falling in towards the inner planets. Create a model Earth Foldable (3D) interactive notebook for Geography and Physics by TRJ - Teaching Resources. Geological Map of the Ocean Floor. Distance to the Centre of the Earth. Why Is the Ocean Salty?

Scientists just figured out where a massive chunk of Earth's crust disappeared to. Walking Through Time: Scotland’s Lost Asteroid… the backstory. 240 million years ago to 250 million years in the future. Continental Drift: 3.3 Billion Years. Greatest Discoveries. Geologic Column: The notion of mantle plumes. Earth Layers.