Category Geology

WHAT IS EARTH MADE OF?

The structure of Earth can be divided into three parts: the crust, the mantle and the core. Made up from mainly oxygen and silicon, the crust is the outermost layer. It is the familiar landscape on which we live: rocks, soil and seabed. Beneath the crust is the mantle, a layer almost 3000 km deep. It is made of metal silicates, sulphides and oxides. This layer is so hot that the rock often flows like sticky road tar – only very, very slowly. Below the mantle is a core of metal, mostly iron, sulphur and nickel. The outer portion of the core is so very hot that the metal is always molten. The Earth’s magnetic field is created here. Earth’s inner core is even hotter – estimated to be around 6000 °C – but the metal is solid because pressure within the inner core is extreme, so the metal cannot melt.

1: The Core

The composition of the Earth begins with the inner parts of the planet. The Earth’s core is the densest part of the planet. It is made up of iron and nickel, and the core is so hot that is heats the rest of the planet around it. The core has chosen how the planet will be heated, and the core of the planet determines the equilibrium of the planet itself.

2: The Magma

The magma underneath the Earth’s surface spins around the world as it keeps the crust warm. The warmth of the magma can be felt in certain parts of the world where the ground is very close to the magma. The magma can be found rising out of the surface of the Earth at volcanoes and underwater cracks in the crust. The magma is the lifeblood of the Earth even though it is quite a scary thing to encounter today.

3: The Crust

The crust of the Earth is the ground that everyone walks on today. The crust is much thinner than the other components of the Earth, but it manages to support all the life on the planet. The Earth’s surface is covered with the crust completely, but much of the Earth’s surface is covered in water. Citizens of the Earth may never explore the floor of the sea, but that area is still a part of the Earth’s crust.

4: Magnetism

The magnetism of the Earth that helps it stay attached to the sun in orbit comes directly from the core. The core’s construction keeps the magnetism of the Earth going in ways that scientists do not understand completely. The magnetism created by the core also helps the Earth create a gravitational field that keeps everyone on the planet.

Credit: AES

Picture credit: Google

HOW DO WE KNOW WHAT EARTH’S INSIDE LOOK LIKE?

Scientists have worked this out from the vibrations from earthquakes and underground explosions. This data is pictured with lines on 3D maps to help scientists understand the structure of Earth’s core.

Core, mantle, and crust are divisions based on composition. The crust makes up less than 1 percent of Earth by mass, consisting of oceanic crust and continental crust is often more felsic rock. The mantle is hot and represents about 68 percent of Earth’s mass. Finally, the core is mostly iron metal. The core makes up about 31% of the Earth.

CRUST AND LITHOSPHERE

Earth’s outer surface is its crust; a cold, thin, brittle outer shell made of rock. The crust is very thin, relative to the radius of the planet. There are two very different types of crust, each with its own distinctive physical and chemical properties.Oceanic crust is composed of magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro. Sediments, primarily muds and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore where it comes off the continents in rivers and on wind currents.

MANTLE
The two most important things about the mantle are: (1) it is made of solid rock, and (2) it is hot. Scientists know that the mantle is made of rock based on evidence from seismic waves, heat flow, and meteorites. The properties fit the ultramafic rock peridotite, which is made of the iron- and magnesium-rich silicate minerals. Peridotite is rarely found at Earth’s surface.Scientists know that the mantle is extremely hot because of the heat flowing outward from it and because of its physical properties. Heat flows in two different ways within the Earth: conduction and convection. Conduction is defined as the heat transfer that occurs through rapid collisions of atoms, which can only happen if the material is solid. Heat flows from warmer to cooler places until all are the same temperature. The mantle is hot mostly because of heat conducted from the core. Convection is the process of a material that can move and flow may develop convection currents.

CORE
At the planet’s center lies a dense metallic core. Scientists know that the core is metal for a few reasons. The density of Earth’s surface layers is much less than the overall density of the planet, as calculated from the planet’s rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85 percent iron metal with nickel metal making up much of the remaining 15 percent. Also, metallic meteorites are thought to be representative of the core.If Earth’s core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because S-waves stop at the inner core. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core.

Credit: Lumen Learning

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11-year-old boy finds 30,000-year-old woolly mammoth?

YEVGENY Salinde, an 11-year-old Russian boy, has found a 30,000-year old perfectly preserved mammoth carcass near his home in Russia’s far north. Experts believe this is the second most well preserved mammoth specimen ever discovered. A similar find like this hasn’t been encountered in a century.

Paleontologists did not only find a skeleton, like initially expected, but a complete carcass – skin, meat, fat hump, organs and a tusk. Scientists estimate the mammoth was 15 to 16 years old when it succumbed in the summer because it lacked an undercoat and had a large.

The total weight of the remains is more than 500 kg, and that includes the right half of the body with soft tissue, skin and hair, skull with one ear, a tusk, various bones and even reproductive organs, the Dolgano-Nentsky administration website announced.

It is believed to be the second best preserved mammoth discovery and the best mammoth find since 1901, when another mammoth was discovered near Beryozovka River in Yakutia, the paper reported.

Zhenya discovered the body 3 kilometres from Sopkarga polar meteorological station, where he lives with his family.

His parents informed scientific experts about the discovery after which the mammoth was taken to Dudinka in a helicopter and put in an ice chamber there. After the remains are studied, Zhenya the mammoth will move to Taymyr natural history museum as a showpiece.

Credit : NDTV

Picture Credit : Google 

What is doomsday fiction?

Imagine a world wrecked by a natural disaster, devastated by nuclear war, or destroyed by a pandemic. While this may sound all too familiar because of the prevailing COVID-19 pandemic, apocalypse fiction is a literary genre that has existed for many years. A subset of science fiction, apocalyptic and post-apocalyptic fiction, also known as doomsday fiction, imagines what life will be like at the end of the world.

How it began

An apocalypse is an event that results in mass destruction and change. Although apocalyptic themes exist in many religious texts, the 20th and 21st centuries have given rise to this genre. The aftermath of World War I, World War II, and the nuclear arms race proved to be fertile ground for writers and filmmakers to conjure up a world plagued by zombies, murderous robots, climate change and even a nuclear holocaust

Apocalyptic vs Post- Apocalyptic

Apocalyptic and post apocalyptic literature is set in a time period where the earth as we know it is coming to an end. An apocalyptic novel or film tells the story of the end of the world, unfolding during the timeline of the story. For example, the 2004 film, “The Day After Tomorrow shows what happens when a sudden worldwide storm plunges the entire planet into a new ice age. On the other hand, post-apocalyptic works portray life in the wake of a cataclysmic event. They focus on how the characters deal with the consequences of a disaster. A 2007 film “1 am Legend” starring Will Smith, is a good example. It follows Robert Neville, a scientist who is the last human survivor of a plague in the whole of New York, as he attempts to find a way to reverse the effects of the human-made virus.

Popular examples

Books written under this genre can be broadly classified (based on their themes) into post-disaster wastelands zombie apocalypse, nature gone wrong, machines taking over the world, and dystopian worlds. Here are a few examples.

Post-disaster wastelands

  • “The Stand” by Stephen King
  • “The Mad Max” film series by James McCausland and George Miller

Zombie Apocalypse

  • World War Z by Max Brooks
  • “The Walking Dead”, a graphic novel series by Robert Kirkman, Tony Moore, and Charlie Adlard

Dystopian worlds

  • “The Hunger Games” by Suzanne Collins
  • “Divergent” by Veronica Roth

Machines taking over

  • “The Maze Runner by James Dashner
  • The Big Melt” by Ned Tillman

 

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