Carbonate Petrography

Carbonate petrography is the study of limestones, dolomites and associated deposits under optical or electron microscopes greatly enhances field studies or core observations and can provide a frame of reference for geochemical studies.

25 strangest Geologic Formations on Earth

The strangest formations on Earth.

What causes Earthquake?

Of these various reasons, faulting related to plate movements is by far the most significant. In other words, most earthquakes are due to slip on faults.

The Geologic Column

As stated earlier, no one locality on Earth provides a complete record of our planet’s history, because stratigraphic columns can contain unconformities. But by correlating rocks from locality to locality at millions of places around the world, geologists have pieced together a composite stratigraphic column, called the geologic column, that represents the entirety of Earth history.

Folds and Foliations

Geometry of Folds Imagine a carpet lying flat on the floor. Push on one end of the carpet, and it will wrinkle or contort into a series of wavelike curves. Stresses developed during mountain building can similarly warp or bend bedding and foliation (or other planar features) in rock. The result a curve in the shape of a rock layer is called a fold.

Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

We Are All Made of Stardust

We Are All Made of Stardust 

Where Do Elements Come From? 

Element factories in space.
Nebulae from which the first-generation stars formed consisted entirely of the lightest atoms, because only these atoms were generated by Big Bang nucleosynthesis. In contrast, the Universe of today contains 92 naturally occurring elements. Where did the other 87 elements come from? In other words, how did elements with larger atomic numbers (such as carbon, sulphur, silicon, iron, gold, and uranium), which are common on Earth, form? Physicists have shown that these elements form during the life cycle of stars, by the process of stellar nucleosynthesis. Because of stellar nucleosynthesis, we can consider stars to be “element factories,” constantly fashioning larger atoms out of smaller atoms. 
What happens to the atoms formed in stars? Some escape into space during the star’s lifetime, simply by moving fast enough to overcome the star’s gravitational pull. The stream of atoms emitted from a star during its lifetime is a stellar wind (figure above a). Some escape only when a star dies. A small or medium star (like our Sun) releases a large shell of gas as it dies, ballooning into a “red giant” during the process, whereas a large star blasts matter into space during a supernova explosion (figure above b). Most very heavy atoms (those with atomic numbers greater than that of iron) require even more violent circumstances to form than generally occurs within a star. In fact, most very heavy atoms form during a supernova explosion. Once ejected into space, atoms from stars and supernova explosions form new nebulae or mix back into existing nebulae.

Universe formation

Universe formation

We stand on a planet, in orbit around a star, speeding through space on the arm of a galaxy. Beyond our galaxy lie hundreds of billions of other galaxies. Where did all this “stuff” the matter of the Universe come from, and when did it first form? For most of human history, a scientific solution to these questions seemed intractable. But in the 1920s, unexpected observations about the nature of light from distant galaxies set astronomers on a path of discovery that ultimately led to a model of Universe formation known as the Big Bang theory. To explain these observations, we must first introduce an important phenomenon called the Doppler effect. We then show how this understanding leads to the recognition that the Universe is expanding, and finally, to the conclusion that this expansion began during the Big Bang, 13.7 billion years ago.

An Image of Our Universe

An Image of Our Universe

What Is the Structure of the Universe? 

Contrasting views of the universe drawn by artist hundreds of years ago.
Think about the mysterious spectacle of a clear night sky. What objects are up there? How big are they? How far away are they? How do they move? How are they arranged? In addressing such questions, ancient philosophers first distinguished between stars (points of light whose locations relative to each other are fixed) and planets (tiny spots of light that move relative to the backdrop of stars). Over the centuries, two schools of thought developed concerning how to explain the configuration of stars and planets, and their relationships to the Earth, Sun, and Moon. The first school advocated a geocentric model (figure above a), in which the Earth sat without moving at the centre of the Universe, while the Moon and the planets whirled around it within a revolving globe of stars. The second school advocated a heliocentric model (figure above b), in which the Sun lay at the centre of the Universe, with the Earth and other planets orbiting around it.

Mars Mission

Planet Earth seen from space

Earth axis has changed

The axis of rotation of Earth is the one that determines the season of our planet. Earth axis as believed previously is the 23.5 degrees which is known from a long time but it's not any more the same as before but has shifted not gradually. There is no reason to include for the shift but evidence can provide the shift. Earth’s Axis has modified where the evidence for it is right in front of us. The season has drifted more ahead. Few years back it, the winter start was from September with intense in December but not any more. The winter now has shifted from September to November with intense in January and February and yet is dragged a lot to April and May. There will in all probability be a lot of weather over future month. Possibly more into March and April. North east is being pounded with historic levels of “Snow hurricanes”. The sun that ought to never be farther north than the tropic of Cancer in middle Mexico or farther south than the Tropic of Capricorn in middle Australia is currently considerably on the far side those points. The sun is currently regarding 2000 miles too way north within the summer shining in our northern windows and too way south within the winter shining in their southern facing windows at sunrise and sunset. 

The orbit round the sun had probably altered the direction of the angle  observations and measurements of the abnormal position of the sun due to a big shift of our axis in Dec 2004 is currently verified.

However, it's additionally considerably shifted once more within the past year for the primary time since 2004. You can measure it for yourself when you see the sun position is too far north of your home in June (northern hemisphere) when it should never be north of the Tropic of Cancer and too far south in the winter.
Many people don't seem to be tuned in to true. You can look into the sun position and verify the weather changes.

Pluto complex geology revealed

As NASA’s New Horizons spacecraft barrels toward Pluto, rapidly approaching its close encounter on July 14, long-distance reconnaissance by the probe is revealing a fascinating surface geology. Far from being a bland, uniform surface, the dwarf planet seems to play host to a complex array of geological features that planetary scientists are already trying to decipher.

The New Horizons probe, hurtling ever closer to Pluto, is beginning to pick up clear signs of surface geology, including unusual polygon-shaped features and sharp transitions between bright areas and a dark region along the equator known as "the whale," project scientists said Friday.

The latest image was snapped Thursday while New Horizons was still 3.3 million miles from its target. As such, features are not yet in razor-sharp focus. But the clarity is steadily improving as New Horizons races toward Pluto at more than 31,000 mph.

The dark anti-polar cap we saw in the earlier, far-blurrier images is still a coherent if mysterious feature, a ragged patch stretching over 320 kilometres (200 miles). Its source is open to wild theorizing: a compositional change due to some To Be Determined process, a region that’s been melted and refrozen as larger crystals, a deposition spot within some temporary, nebulous atmosphere formed by stealing stray gases from Pluto, or something altogether different. Unlike the cantaloupe-texture hexagons of Pluto, Charon is home of circular features that are very likely craters. The most prominent suspected crater is a 96.5 kilometre (60 mile) diameter circle near the south pole. Bright rays radiating out from from it suggest it formed relatively recently, meaning sometime within the last billion years. The dark centre suggests the crater floor might be exposing a different type of icy material than coats most of the planet, or ice that refroze with larger, less-reflective grains after the impact. But the most interesting features of all are dark, linear areas: potential chasms. If they are chasms, we’re looking at gaping canyons that put Earth’s wimpy Grand Canyon in a corner of shame for being such a weak attempt at splitting the surface. However exactly we end up defining it, if it’s a fault or a surface disruption with depth of any type, it’s shocking us by revealing moon we thought would be near featureless and rather boring is actually home to some sort of geological activity. Or maybe Mass Effect was unintentionally truthful, and those are the flaws in otherwise perfect camouflage for a mass relay.

The "tail" of the dark equatorial region nicknamed the "whale" has what appears to be a large, lighter-coloured peninsula and tiny speck of light material, suggesting some kind of complex geology or broken landscape. A "polygonal feature" somewhat north of the equator could be crevasses with shapes governed by shearing minerals or some other, less obvious phenomenon.

Earth's axial tilt result in seasonal changes

Earth tilt angle is 23.5 degrees

Earth is tilted at an angle of 23.5 degree across its axis of rotation. This tilt is responsible for seasonal changes, without this there will be no seasonal changes but instead single season per area. The most direct sun rays hit areas would always be warmer. The increase in tilt of the Earth severe the the seasons. Winter becomes even more colder and summer becomes more warm. Nowadays tilt is 23.5 degree but it changes with a cycle of about 40,000 years the tilt varies between 22.1 and 24.5. Cooling of summers are thought to allow snow and ice formation on the high altitude areas which can stay for more time and becomes solid making massive ice sheets. Earth covered with more snow will reflect more sun light and Earth will becomes more and more cold. This is responsible for the ice age where Earth is covered with snow. 

The tilt as implies to the seasonal changes other factors that gives seasonal changes are the change in the rotation of Earth's orbit. The other is the precession, changes in axial precession increase seasonal contrast between northern and southern hemisphere. When northern hemisphere have summer southern will be away from sun which will be the winter season. 
Eccentricity is the change in Earth's orbital which can be away from sun or near the sun. When it is at the furthest distance from the sun, temperature will be cooler. The near sun orbital, heating process will be at peak warming up the Earth. Ice sheets will melt and transgression will occur, water level will rise. Changes in eccentricity affect the Earth sun distance, The shape of Earth becomes nearly circular from elliptical in a cycle that takes between 90,000 to 100,000 years. This cycle is called Milakovitch cycle which was after Milutin Milankovitch (1879-1958).